NTI Trinirt TX, Tx51-151 Operating Instructions Manual

Trinity Tx

Model Numbers: Tx 51 - 151
Version Date: 2013-06-20

INSTALLATION AND OPERATION INSTRUCTIONS FOR
TRINITY Tx BOILER

TABLE OF CONTENTS

HAZARD SYMBOLS AND DEFINITIONS

Danger Sign: Indicates a hazardous situation which, if not avoided, will
result in serious injury or death.

Warning Sign: Indicates a hazardous situation which, if not avoided,
could result in serious injury or death.

Caution Sign plus Safety Alert Symbol: Indicates a hazardous situation
which, if not avoided, could result in minor or moderate injury.

Caution Sign without Safety Alert Symbol: Indicates a hazardous
situation which, if not avoided, could result in property damage.

Notice Sign: Indicates a hazardous situation which, if not avoided,
could result in property damage.

This Boiler must be installed by a licensed and trained Heating
Technician or the Warranty is Void. Failure to properly install this

unit may result in property damage, serious injury to occupants, or possibly death.

NEW PRODUCT LINE

High Efficiency

Condensing Gas Boiler

H

NTI # 84874

2

Trinity │Installation and Operation Instructions Tx Series

Read Before Proceeding

If you do not follow these instructions exactly, a fire or explosion may result causing
property damage, serious injury or death.

FOR YOUR SAFETY, READ BEFORE OPERATING_

A) This boiler does not have a pilot. It is equipped with an ignition device which automatically lights the

burner. Do not try to light the burner by hand.

B) BEFORE OPERATING smell all around the boiler area for gas. Be sure to smell next to the floor
because some gas is heavier than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS:

• Do not try to light any boiler.

• Do not touch any electric switch.

• Do not use any phone in your building.

• Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.

• If you cannot reach your gas supplier, call the fire department.

C) Use only your hand to turn the gas “shutoff” valve. Never use tools. If the handle will not turn by hand,

don't try to repair it, call a qualified service technician. Force or attempted repair may result in a fire or
explosion.

D) Do not use this boiler if any part has been under water. Immediately call a qualified service technician

to inspect the boiler and to replace any part of the control system and any gas control which has been
under water.

OPERATING INSTRUCTIONS_

1. STOP! Read the safety information above very carefully.

2. Set the thermostat to lowest setting. Turn off all electric power to the boiler.

3. This boiler does not have a pilot. It is equipped with an ignition device which automatically lights the

burner. Do not try to light the burner by hand.

4. Turn the manual gas valve to the OFF position. Remove front access panel.

5. Wait five (5) minutes to clear out any gas. Then smell for gas, including near the floor. If you smell gas,

STOP! Follow “B” in the safety information above. If you don't smell gas, go to the next step.

6. Turn the manual gas valve ON. Wait an additional five (5) minutes smelling for gas.

7. Replace the front access panel.

8. Set thermostat to highest setting. Turn on all electric power to the boiler.

9. Ignition sequence is automatic. Combustion will occur after a brief fan purge.

10. If ignition does not occur, follow the instructions “To Turn Off Gas To Boiler” and call your service

technician or gas supplier.

TO TURN OFF GAS TO THE BOILER_

1. STOP! Read the safety information above very carefully.

2. Turn off all electric power to the boiler.

3. Turn the manual gas valve to the OFF position.

Crystalline Silica - Certain components confined in the combustion chamber may

contain this potential carcinogen. Improper installation, adjustment, alteration, service or
maintenance can cause property damage, serious injury (exposure to hazardous materials) or death. Refer to
Section 15.0 for information on handling instructions and recommended personal protective equipment.
Installation and service must be performed by a qualified installer, service agency or the gas supplier (who must
read and follow the supplied instructions before installing, servicing, or removing this boiler. This boiler
contains materials that have been identified as carcinogenic, or possibly carcinogenic, to humans).

Void Warranty - This Boiler must have water flowing through it whenever the burner is

on or it will damage the unit and void the warranty. Failure to follow these instructions
may result in serious injury or death.

Tx Series Installation and Operation Instructions │Trinity

3

Energy Saving Feature - This boiler is equipped with a feature that saves energy by

reducing the boiler water temperature as the heating load decreases. This feature is
equipped with an override which is provided primarily to permit the use of an external energy management
system that serves the same function. THIS OVERRIDE MUST NOT BE USED UNLESS AT LEAST ONE
OF THE FOLLOWING CONDITIONS IS TRUE :

 An external energy management system is installed that reduces the boiler water temperature as the heating

load decreases.

 This boiler is not used for any space heating.
 This boiler is part of a modular or multiple boiler system having a total input of 300,000 BTU/hr or greater.
 This boiler is equipped with a tankless coil.

1.0 INTRODUCTION
General Installation Requirements

The installation of your NTI Trinity Tx gas boiler must conform to the requirements of this manual, your local
authority, and the National Fuel Gas Code ANSI Z223.1 and or CAN/CGA B149 Installation Codes. Where

required by the Authority, the installation must conform to the standard for “Controls and Safety Devices for

Automatically Fired Boilers ANSI/ASME CSD-1.
This document pertains to the correct installation and operation of NTI Trinity boiler model Tx. The instructions

detailed in this document supersede any and all previous instructions provided by NTI, written or otherwise.
Each unit is provided with the following:

1. Installation and Operating Instructions,

2. Trinity Users’ Manual, and

3. Natural Gas to LP Conversion Kit*
* The conversion kit is required to convert the boiler so it will safely operate with Propane Gas.

Read and understand this entire document prior to proceeding with the installation of the
Trinity Tx. Failure to follow the instructions outlined in this document will result in

property damage, serious injury or death.

User Responsibilities

This boiler must be installed and serviced by a qualified installer or service technician. This boiler must be
serviced and inspected annually when operating in normal residential applications. Demanding applications or
extreme conditions (i.e. when operating with LP-Propane) may require more frequent service and inspection. As
the User/Owner of this equipment, you are responsible for ensuring the maintenance is performed at the required
intervals (see Section 14 – Annual Maintenance and Inspection).

Failure to have the boiler properly serviced and inspected on a regular basis by a qualified
service technician may result in property damage, serious injury or death.

Failure to keep the Vent and Combustion Air Intake clear of ice, snow, and other debris
may result in property damage, serious injury, or death.

Installer Responsibilities

As the installing technician it is your responsibility to ensure the installation is performed in accordance with this
instruction manual as well as any applicable local or National installation codes. It is also your responsibility to
inform the User/Owner of their obligation with respect to the above description under “User Responsibilities”.
Failure to follow this warning could result in fire, serious injury, or death.

4

Trinity │Installation and Operation Instructions Tx Series

Failure to use the appropriate Natural to LP Conversion Kit and Orifice when operating
the Trinity Tx to operate with Propane will result in extremely dangerous burner

operation leading to property damage, serious injury or death. Refer to section titled ATTENTION:
LIQUEFIED PETROLEUM (LP) PROPANE for applicable conversion kit and LP orifice numbers.

ATTENTION: LIQUEFIED PETROLEUM (LP) PROPANE

The Trinity Tx is factory set to operate with Natural Gas. BEFORE OPERATING WITH PROPANE, the
specified LP Conversion Kit and Orifice must be installed to convert the boiler so it will operate safely with
LP Propane. The correct kit and LP orifice is listed below (Each kit comes with conversion instructions).

Liquefied Petroleum (LP) propane gas is heavier than air; therefore, it is imperative that your Trinity Tx boiler
is not installed in a pit or similar location that will permit heavier than air gas to collect. Local Codes may
require boilers fueled with LP gas be provided with an approved means of removing unburned gases from the
room. Check your local codes for this requirement.

Natural to LP Propane Conversion Kit_
Model Number Kit Number LP Orifice
Tx51 84867-1 3.5mm
Tx81 84867-2 3.8mm
Tx101 84867-3 4.2mm
Tx151(C) 84867-4 5.05mm

Boiler Vent / Air-Inlet Piping

The Trinity Tx is certified as a “Category IV” boiler, and requires a “Special Venting
System” designed for pressurized venting. The exhaust gases must be piped directly to

the outdoors using the vent materials and rules outlined in these instructions. Failure to follow these instructions
will result in serious injury or death.

5

IN THE STATE OF MASSACHUSETTS ONLY

(a) For all horizontally vented gas fueled equipment installed in every dwelling, building or structure used in whole or

in part for residential purposes, including those owned and operated by the Commonwealth and where the side wall
exhaust vent termination is less than seven (7) feet above finished grade in the area of the venting, including but not
limited to decks and porches, the following requirements shall be satisfied:

1. INSTALLATION OF CARBON MONOXIDE DETECTORS At the time of installation of the side wall

horizontal vented gas fueled equipment, the installing plumber or gas fitter shall observe that a hard wired
carbon monoxide detector with an alarm and battery back-up is installed on the floor level where the gas
equipment is to be installed and on each additional level of the dwelling, building or structure served by the
equipment. It shall be the responsibility of the property owner to secure the services of qualified licensed
professionals for the installation of hard wired carbon monoxide detectors.

a. In the event that the side wall horizontally vented gas fueled equipment is installed in a crawl space or an

attic, the hard wired carbon monoxide detector with alarm and battery back-up may be installed on the next
adjacent floor level.

b. In the event that the requirements of this subdivision can not be met at the time of completion of

installation, the owner shall have a period of 30 days to comply with the above requirements; provided,
however, that during said 30 day period a battery operated carbon monoxide detector with an alarm shall
be installed.

2. APPROVED CARBON MONOXIDE DETECTORS Each carbon monoxide detector as required in accordance

with the above provisions shall comply with NFPA 720 and be ANSI/UL 2034 listed and IAS certified.

3. SIGNAGE A metal or plastic identification plate shall be permanently mounted to the exterior of the building

at a minimum height of eight (8) feet above grade directly in line with the exhaust vent terminal for the
horizontally vented gas fueled heating boiler or equipment. The sign shall read, in print size no less than one­half (1/2) inch in size, “GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUCTIONS”
(plate included with boiler).

4. INSPECTION The state or local gas inspector of the side wall horizontally vented gas fueled equipment shall

not approve the installation unless, upon inspection, the inspector observes carbon monoxide detectors and
signage installed in accordance with the provisions of 248 CMR 5.08(2)(a)1 through 4.

(b) EXEMPTIONS: The following equipment is exempt from 248 CMR 5.08(2)(a)1 through 4:

1. The equipment listed in Chapter 10 entitled “Equipment Not Required To Be Vented” in the most current

edition of NFPA 54 as adopted by the Board; and

2. Product Approved side wall horizontally vented gas fueled equipment installed in a room or structure separate

from the dwelling, building or structure used in whole or in part for residential purposes.

(c) MANUFACTURER REQUIREMENTS – GAS EQUIPMENT VENTING SYSTEM PROVIDED: When the

manufacturer of Product Approved side wall horizontally vented gas equipment provides a venting system design or
venting system components with the equipment, the instructions provided by the manufacturer for installation of the
equipment and the venting system shall include:

1. Detailed instructions for installation of the venting system design or the venting system components; and

2. A complete parts list for the venting system design or venting system.

(d) MANUFACTURER REQUIREMENTS – GAS EQUIPMENT VENTING SYSTEM NOT PROVIDED:

When the manufacturer of a Product Approved side wall horizontally vented gas fueled equipment does not provide
the parts for venting the flue gases, but identifies “special venting systems”, the following requirements shall be
satisfied by the manufacturer:

1. The referenced “special venting system” instructions shall be included with the appliance or equipment

installation instructions; and

2. The “special venting system” shall be Product Approved by the Board, and the instructions for that system shall

include a parts list and detailed installation instructions.

(e) A copy of all installation instructions for all Product Approved side wall horizontally vented gas fueled equipment,

all venting instructions, all parts list for venting instructions, and/or all venting design instructions shall remain with
the appliance or equipment at the completion of the installation.

Tx Series Installation and Operation Instructions │Trinity

6

DESCRIPTION

Tx51

Tx81

Tx101

Tx151

Tx151C

CSA Input Modulation

1

[MBH]

9.2-46

16.4-82

20.2-101

30.2-151

30.2-151

DOE Heating Capacity

1,2

[MBH]

42

75

92

138

138

Net I=B=R Rating

1,2

[MBH]

36

65

80

120

120

DOE AFUE2 [%]

93.1

Water Connections – NPT [in.]

1

3/4

Gas Connection - NPT, in.

½

Vent/Air-inlet Pipe Diameter
[in.] 3

2 or 3

Dimensions H x W x D [in.]

31-1/4 x 18 x 16

Approx. Boiler Weight
with Water [lbs.]

77

79

86

87

98

Approx. Boiler Water Content

[Gallons]

0.5

0.6

0.7

0.8

1

Electrical Rating

120V/1Ph/60Hz/less than 12A

Notes:

1

Listed Input and Output ratings are at minimum vent lengths at an altitude of 0-2000ft. Numbers will be lower with

longer venting and/or altitudes greater than 2000ft.

2

Ratings based on standard test procedures prescribed by the U.S. Department of Energy.

3

Trinity Tx requires a special venting system, use only vent materials and methods detailed in these instructions.

Elevations

2001 ft [610 m]

3000 ft [914 m]

4000 ft [1219 m]

4500 ft [1372 m]

5000 ft [1524 m]

In Canada 1

de-rate by 10%

de-rate by 10%

de-rate by 10%

de-rate by 10%

de-rate % may vary

In USA 2

-

de-rate by 4%

de-rate by 8%

de-rate by 8%

de-rate by 12%

Notes:

1

Canada: Altitudes between 2000-4500 ft [610-1372 m], de-rate by 10%. Consult local authorities for de-rating

capacities for altitudes above 4500 ft [1372 m].

2

USA: De-rate capacity by 4% for every 1000 ft [305 m] over 2000 ft [610 m].

Trinity │Installation and Operation Instructions Tx Series

2.0 SPECIFICATIONS

Table 2-1 Trinity Tx Specifications

Wall mounting of unit requires two people to lift the boiler into place. Failure to follow
these instructions may result in property damage or personal injury.

High Altitude Operation

The Trinity is designed to operate at its maximum listed capacity in installations located at 0-2000ft above Sea
Level. Since the density of air decreases as elevation increases, maximum specified capacity should be de-rated
for elevations above 2000 ft [610 m] in accordance with Table 2-2.

Table 2-2 De-rate % for High Altitudes

Combustion – At elevations above 2000 feet, the combustion of the boiler must be

checked with a calibrated combustion analyzer to ensure safe and reliable operation. It is
the Installers responsibility to check the combustion and to adjust the combustion in accordance with
Section 9.0. Failure to follow these instructions may result in property damage, serious injury, or death.

7

Model No.

Clearances

Dimensions - inches [mm]

Front

Top

Sides

Back

Bottom

Flue Pipe

Trinity Tx

Minimum

24 [610] 1

12 [305]

4 [102]

0

9 [229]

1 [25]

Recommended

36 [914]

24 [610]

12 [305]

0

24 [610]

1 [25]

Notes:

1

6” if surface is removable allowing a minimum of 24” [610 mm] clearance (i.e. closet installation). See Ventilation Air
Opening dimensions in Figure 3-1.

Tx Series Installation and Operation Instructions │Trinity

3.0 BOILER LOCATION

In all cases, the Trinity Tx must be installed indoors in a dry location where the ambient temperature must be
maintained above freezing and below 100F [38C]. All boiler components must be protected from dripping,
spraying water, or rain during operation and servicing. Consider the proximity of system piping, gas and
electrical supply, condensate disposal drain, and proximity to vent termination when determining the best boiler
location.

Boiler Area Ventilation Air Openings

If boiler area clearances are less than the recommended clearances specified in Table 3-1, the boiler area must be
ventilated (Exception: if the boiler area/room has a volume of 150 ft3 or greater, ventilation of the boiler room is
not required). Each ventilation air opening must meet the minimum requirements of 1 in2 per 1000 Btu/hr, but
not less than 100 in2. The lower ventilation opening must be located within 6” of the floor while the upper
opening must be located 6” from the top of the space.

approved CPVC, Polypropylene or Stainless Steel vent pipe and fittings can be used. See Table 4-4 for a list of
approved materials. Under all circumstances, the minimum clearances listed in Table 3-1 must be provided.

Closet Installations

For closet installations it is necessary to provide two ventilation air openings as shown in Figure 3-1, each
providing a minimum area equal to 1 in2 per 1000 Btu/hr, but not less than 100 in2 and within 6” of the top and
bottom of the closet door. See Table 3-1 for minimum clearances.

Alcove Installations

Alcove installations have the same minimum clearances as closet installations, except the front must be
completely open to the room at a distance no greater than 18” [457 mm] from the front of the boiler and the
room is at least three (3) times the size of the alcove. Provided these conditions are met, the boiler requires no
extra ventilation air openings to the space. See Table 3-1for minimum clearances.

Residential Garage Installations

When installed in a residential garage, mount the boiler a minimum of 18” [457 mm] above the floor. Locate or
protect the boiler so it cannot be damaged by a moving vehicle. Check with your local authorities for other
possible regulations pertaining to the installation of a boiler in a garage.

Wall Mounting Installations

The Tx is provided with integrated wall mounting brackets. Refer to Figure 3-2 for instructions and illustrations
on wall mounting.

Table 3-1 Minimum Clearances for Installation and Service

Water or flood damaged components must be replaced immediately with new factory-

approved components as failure to do so may result in fire, serious injury, or death.

If the "Boiler Area" does not meet the recommended clearances listed in Table 3-1, and if

the boiler area has a volume less than 150 ft3, it is considered a Closet or Alcove. In US /

Canada, PVC vent pipe and fittings shall not be used within the closet or alcove; only

Closet/alcove installations in US and Canada require approved CPVC, Polypropylene or
Stainless Steel vent and air-inlet pipe and fittings (see Table 4-4); PVC is not permitted.

Failure to follow these instructions may result in damage or serious injury.

8

Figure 3-1 Closet Installation, Minimum Clearances

(Non-Combi Model Shown)

Ventilation Air Openings
are not required if the
boiler area meets the
Recommended Clearances
listed in Table 3-1.

Bottom ventilation opening
Max. 6” above floor / bottom

Top ventilation opening
Max. 6” below ceiling / top

Sides = 4”

Front = 6”

(if removable)

Removable surface /
closet door

Ventilation air opening
1in2 per 1000 Btu/hr,
min. 100in

2

Ventilation air opening
1in2 per 1000 Btu/hr,
min. 100in

2

Min. 1” clearance for hot

water and vent pipes

Bottom = 9”

Top = 12”

Trinity │Installation and Operation Instructions Tx Series

9

Figure 3-2 Wall Mounting Instructions

 Leave the Top Wall-mount Bracket (A) intact

and remove the Bottom Wall-mount Bracket
(B) that is attached to the bottom-back of the

appliance. Save mounting hardware for Step 4.

 Secure Bottom Bracket (B), removed from the

bottom back of the boiler in Step 1, to a solid
wall using field supplied lag screws (anchors
when mounting to a concrete wall) that are
adequate to support the weight of the appliance
(refer to Table 2-1 Specifications). Ensure the
bracket is level and flush to the wall. Mounting
holes to be on the bottom with flange pointed
upward and angled away from the wall.

 Mount the appliance to the wall by aligning the

two wall mount brackets, Top Bracket (A)
with the Bottom bracket (B). Slide the top
bracket fastened to the boiler down over the
wall-mounted bracket until it hooks.

 Once the appliance is resting securely on the

wall, attach the L-shaped Bracket (C) to the
underside of the appliance using the mounting
hardware removed in Step 1. Next anchor the
L-shaped Bracket (C) to the wall as shown
using field supplied hardware.

Failure to follow instructions may
result in fire, serious injury, or death.

This unit requires two people to lift it
or damage and injury may result.

Top Bracket (A)

Bottom

Bracket (B)



Bottom
Bracket (B)





L-shaped Bracket (C)

shipped with boiler kit box



Wall

Boiler

Ensure Bracket
(A) fully inserts
into Bracket (B)

(B)

(A)

Tx Series Installation and Operation Instructions │Trinity

10

Trinity │Installation and Operation Instructions Tx Series

4.0 GENERAL VENTING

The Trinity Tx is certified as a “Category IV” boiler requiring a “Special Venting System” designed for
pressurized venting. The Exhaust Vent must be piped to the outdoors, using the vent materials and rules outlined
in this section. Under no conditions may this unit vent gases into a masonry chimney, unless it is vacant, and
utilizes the approved venting material and rules described in this section.

Direct Vent Installation (Best Practice)

When installed as a Direct Vent boiler the combustion air-inlet must also be piped directly to the outdoors using
the methods described in this section and in accordance with the National Fuel Gas Code, ANSI Z223.1 (U.S.) or
CSA B149.1 (Canada) and local requirements.

Installation Using Indoor Combustion Air

When the installation uses Indoor Combustion Air (i.e. piping is not directly connecting the appliance air-inlet
fitting to the outdoors), the combustion air-inlet is drawn from Indoors or Outdoors via the appliance area using
the methods described in this section and in accordance with the National Fuel Gas Code, ANSI Z223.1 (U.S.) or
CSA B149.1 (Canada) and local requirements.

appliances may result in personal injury or death.
Indoor Combustion Air - Opening Size and Location: The methods detailed below for determining Opening

Size and Location for accessing indoor combustion air, shall be used when the air infiltration rate is adequate, i.e.
greater than 0.4 ACH (air changes per hour) and when the boiler area and communicating spaces have a
minimum volume of 50 cubic ft per 1000 Btu/hr. If the air infiltration rate is known to be less that 0.4 ACH,
refer to the National Fuel Gas Code for further guidance.

1. Combined spaces on the same story – Each opening shall have a minimum free area of 1 in.2/1000 Btu/hr

of the total input rating of all appliances in the space, but not less than 100 in.2. One opening shall
commence within 12 in. of the top, and one opening shall commence within 12 in. of the bottom, of the
enclosure, see Figure 4-1a. The minimum dimension of air openings shall be not less than 3in.

2. Combined spaces in different stories – The volumes of spaces in different stories shall be considered as

communicating spaces where such spaces are connected by one or more openings in doors or floors having a
total minimum free area of 2 in.2/1000 Btu/hr of total input rating of all appliances.

Outdoor Combustion Air – Opening Size and Location: Outdoor combustion air shall be provided through
opening(s) to the outdoors in accordance with the methods detailed below. The minimum dimension of air
openings shall not be less than 3in.

1. Two Permanent Openings Method – Two permanent openings, one commencing within 12in. of the top,

and one commencing within 12in. of the bottom of the enclosure, shall be provided. The openings shall
communicate directly, or by ducts, with the outdoors or spaces that freely communicate with the outdoors, as
follows:

a. Where communicating with the outdoors or where communicating to the outdoors through vertical ducts,

each opening shall have a minimum free area of 1 in.2/4000 Btu/hr of total input rating of all appliances
in the enclosure; see Figures 4-1b and 4-1c.

b. Where communicating with the outdoors through horizontal ducts, each opening shall have a minimum

free area of 1 in.2/2000 Btu/hr of total input rating of all appliances in the enclosure; see Figure 4-1d.

Vent and Air-inlet are to be piped separately. The Trinity Tx cannot share a common vent
or air-inlet with multiple boilers. Failure to comply will result in serious injury or death.

The boiler shall be located so as not to interfere with proper circulation of combustion,
ventilation, and dilution air.

Make up air requirements for the operation of exhaust fans, kitchen ventilation systems,

clothes dryers, and fireplaces shall be considered in determining the adequacy of a space

to provide combustion air requirements. Failure to ensure adequate make up air to all

11

Figure 4-1(a) Indoor Air

Figure 4-1(b) Two Vertical Ducts

Figure 4-1(c) Two Vertical Ducts

Figure 4-1(d) Two Horizontal Ducts

Figure 4-1(e) One Duct Options

Opening (within

1ft of ceiling)

Opening (within

1ft of floor)

Exhaust Vent

Opening

Opening

Exhaust Vent

Ventilation Louvers
(each end of attic)

Ventilated & unheated
crawl space

Exhaust Vent

Ventilation Louvers
(each end of attic)

Opening

Opening (duct

extended to within

1ft of floor)

Exhaust Vent

Opening (within

1ft of ceiling)

Opening (within

1ft of floor)

Exhaust Vent

Ventilation Louvers
(each end of attic)

Opening Option B

(within 1ft of ceiling)

Opening Option A

Tx Series Installation and Operation Instructions │Trinity

2. One Permanent Opening Method – One permanent opening, commencing within 12 in. of the top of the

enclosure, shall be provided. The appliance shall have clearances of at least 1 in. from the sides and back
and 6 in. from the front of the appliance. The opening shall directly communicate with the outdoors or shall
communicate through a vertical or horizontal duct to the outdoors or spaces that freely communicate with the
outdoors (see Figure 4-1e) and shall have a minimum free area of the following:
a. 1 in.2/3000 Btu/hr of the total input rating of all appliances located in the enclosure, and
b. Not less than the sum of the areas of all appliance vent connectors in the space.

3. Combination Indoor and Outdoor Combustion Air – The use of a combination of indoor and outdoor

combustion air shall be in accordance with the following:
a. Indoor Openings – where used, openings connecting the interior spaces shall comply with “Indoor

Combustion Air – Opening and Size and Location” described above.

b. Outdoor Openings – Outdoor opening(s) shall be located in accordance with “Outdoor Combustion Air

– Opening Size and Location” described above.

c. Outdoor Opening(s) Size – The outdoor opening(s) size shall be calculated in accordance with the

following:

i. The ratio of interior spaces shall be the available volume of all communicating spaces divided by the

required volume (i.e. 50 cubic ft per 1000 Btu/hr if 0.4 ACH or greater).

ii. The outdoor size reduction factor shall be 1 minus the ratio of interior spaces.

iii. The minimum size of outdoor opening(s) shall be the full size of outdoor opening(s) calculated in

accordance with “Outdoor Combustion Air – Opening Size and Location” described above, multiplied
by the reduction factor. The minimum dimension of air openings shall not be less than 3 in.

12

Products to Avoid

Contaminated Sources to Avoid

Antistatic fabric softeners, bleaches, detergents, cleaners

Laundry facilities

Perchloroethylene (PCE), hydrocarbon based cleaners

Dry cleaning facilities

Chemical fertilizer, herbicides/pesticides, dust, methane gas

Farms or areas with livestock and manure

Paint or varnish removers, cements or glues, sawdust

Wood working or furniture refinishing shops

Water chlorination chemicals (chloride, fluoride)

Swimming pools, hot tubs

Solvents, cutting oils, fiberglass, cleaning solvents

Auto body or metal working shops

Refrigerant charge with CFC or HCFC

Refrigerant repair shops

Permanent wave solutions

Beauty shops

Fixer, hydrochloric acid (muriatic acid), bromide, iodine

Photo labs, chemical / plastics processing plants

Cement powder, crack fill dust, cellulose, fiber based insulation

Concrete plant or construction site

Trinity │Installation and Operation Instructions Tx Series

Combustion Air-inlet Contamination

Be careful not to locate the air-inlet termination in an area where contaminants can be drawn in and used for
combustion. Combustion air containing dust, debris or air-borne contaminants will drastically increase the
required maintenance and may cause a corrosive reaction in the Heat Exchanger which could result in premature
failure, fire, serious injury, or death. See Table 4-1 for a list of areas to avoid when terminating air-inlet piping:

Table 4-1 Corrosive Products and Contaminant Sources

Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this

or any other boiler. Failure to follow instructions may result in serious injury or death.

It is BEST PRACTICE to pipe the combustion air-inlet directly to the outdoors (Direct

Vent installation) to avoid contamination often contained in indoor air.

Flammable Solvents and Plastic Piping

Due to the extremely flammable characteristics of most glues, cements, solvents and primers used in the process
of joining plastic vent and air-inlet pipe, explosive solvent vapors must be evacuated from the vent and air-inlet
prior to start-up. Avoid using excess cement or primer that may lead to pooling inside the pipe assembly. Freshly
assembled piping assembly should be allowed to cure for a minimum of 8 hours before applying power to the gas
fired boiler. Refer to Mandatory Pre-commissioning Procedure for Plastic Venting in this section.

to reduce these risks. Failure to follow these instructions can cause explosions, property damage, injury or death.

Mandatory Pre-commissioning Procedure for Plastic Venting (PVC or CPVC)

1) Working with the power turned off to the boiler, completely install the vent and air intake system, securely

cementing joints together. If possible, allow primers/cements to cure for 8 hours before firing the burner. If
curing time is less than 8 hours, proceed with Steps 2 through 6.

2) Maintain the boiler gas supply shut-off valve in the off position.

3) Remove the cable from the Spark Ignition Electrode and Ignition Controller.

4) Turn power on to the boiler and apply a heat demand.

5) Allow for 3 complete trials for ignition, consisting of pre and post purge of the combustion blower, until an

ignition lockout occurs. Repeat the process two more times (i.e. 9 complete ignition sequences in total).

6) Turn power off and reconnect the cable to the Spark Ignition Transformer.

Flammable Cements and Primers – It is the installers’ responsibility to familiarize

themselves with the hazards associated with explosive solvents and to take all precautions

Do not apply power to the boiler prior to Step 4 in the Mandatory Pre-commissioning

Procedure for Plastic Venting.

Spark Ignition Circuit - Maintain a safe distance (2 inches minimum) from the spark

ignition circuit to avoid injury from electrical shock.

13

Tx Series Installation and Operation Instructions │Trinity

Near Boiler Vent/Air-inlet Piping

The Trinity Tx employs universal Vent and Air-inlet appliance adapters that accept either 3” PVC/CPVC or 3”
Polypropylene (PPs) venting, without the need for additional adapters. The appliance adapters incorporate two
seals, one for the larger diameter PVC/CPVC pipe (3.5” OD), and one for the smaller diameter PPs pipe (3.15”
OD). The exhaust/vent adapter uses a toothed-ring to prevent the vent pipe from being pulled out once it is
inserted.

PVC/CPVC Piping – Remove the lower gasket and toothed-ring from the exhaust adapter to avoid damage from
flue gas condensate; the 3” PVC/CPVC has an outside diameter of 3.5” and will seat into the upper portion of the
adapter. Ensure the upper gasket and toothed-ring are in place and properly positioned prior to installation.
Ensure the venting system does not apply a load or strain on the boiler flue outlet adapter; recommend using two
elbows to create a “swing joint” to reduce potential strain on vent piping and cemented joints. See Figure 4-2(a).

PPs Piping – 3” PPs has an outside diameter of 3.15” and will seat into the lower portion of the adapter. Ensure
the lower gasket and toothed-ring are in place and properly positioned prior to installation Ensure the venting
system does not apply a load or strain on the boiler flue outlet adapter; recommend using an elbow with an offset
to reduce potential strain on vent piping and cemented joints. See Figure 4-2(b).

Stainless Steel Piping – The Trinity Tx has been tested and approved for use with DuraVent – FasNSeal AL29-
4C Stainless Steel Special Gas Vent. Venting with FasNSeal will require DuraVent adapter part number 300715
(contact DuraVent at 1-800-835-4429 or www.duravent.com). Remove the lower gasket and toothed-ring from
the appliance exhaust adapter to avoid damage from flue gas condensate; the DuraVent adapter has an outside
diameter of 3.5” and will seat into the upper portion of the appliance adapter. Ensure the upper gasket and
toothed-ring are in place and properly positioned prior to installation. Ensure the venting system does not apply
a load or strain on the boiler flue outlet adapter; recommend using two elbows to create a “swing joint” to reduce
potential strain on vent piping and cemented joints. See Figure 4-2(c).

Gasket Seating - Improper seating can cause leakage and eventual failure of the sealing

gasket. Ensure the vent pipe is adequately beveled prior to inserting into the boiler flue

adapter. Failure to follow these instructions may result in serious injury or death.

Toothed-Ring - Failure to ensure the toothed-ring is properly in place and securing the

exhaust vent pipe to the appliance adapter may result in serious injury or death.

Exhaust venting must be supported to reduce strain on piping joints. Failure to follow

these instructions may result in result in damage, serious injury or death.

In Canada, the first 3 ft (915 mm) of vent piping must be readily accessible for inspection.

14

Figure 4-2(a) Near Boiler Vent Connections (PVC/CPVC)

Exhaust Vent Preparation (PVC/CPVC)

Near Boiler Venting (PVC/CPVC)

Figure 4-2(b) Near Boiler Vent Connections (PPs – Polypropylene)

Exhaust Vent Preparation (PPs)

Near Boiler Venting (PPs)



Air-inlet - check with applicable local codes for acceptable pipe material.

Flue Outlet

Adapter (factory

supplied)

PVC/CPVC

Exhaust Vent

Swing Joint

to attain slope in

horizontal runs

Air-inlet
Pipe *

Air Inlet
Adapter

(factory
supplied)

PVC/CPVC – beveled

PPs Gasket & Ring –

remove lower gasket &

ring (not used w/PVC)

PVC Gasket & Ring – retain

upper gasket & ring

PPs Pipe – beveled

PPs Gasket & Ring –

retain lower gasket & ring

Air-inlet Adapter

(factory supplied)

PPs Elbow

w/ offset angle to
account for slope

PPs Exhaust Vent

PPs Air-inlet Pipe*

Flue Outlet Adapter

(factory supplied)

Trinity │Installation and Operation Instructions Tx Series

15

Figure 4-2(c) Near Boiler Vent Connections (SS – Stainless Steel)

Exhaust Vent Preparation (SS)

Near Boiler Venting (SS)

Flue Outlet

Adapter (factory

supplied)

SS Exhaust
Vent Pipe

Swing Joint

to attain slope in

horizontal runs

SS Air-inlet Pipe

SS Adapter
(Table 4-3)

Air-inlet Adapter

(factory supplied)

SS Adapter (Table 4-3)

PPs Gasket & Ring –

remove lower gasket &

ring (not used w/ PVC)

PVC Gasket & Ring – retain

upper gasket & ring

Tx Series Installation and Operation Instructions │Trinity

16

Items 1

Materials

2, 3

Venting System Standards

All Vent and Air-Inlet
materials installed on gas
fired appliances in CAN/US
must meet the Standards
listed in this Table. Failure
to comply could result in
fire, serious injury or death.

United States

Canada 4

Vent Piping

and Fittings

PVC - DWV

ANSI/ASTM D2265

All venting material in

Canada must be

ULC S636 approved.

See Note 4 below for

appropriate temperature

applications.

PVC Schedule 40

ANSI/ASTM D1785

CPVC Schedule 40

ANSI/ASTM F441

Stainless Steel (SS)

UL-1738

Polypropylene (PP)

-

Pipe Cement
PVC

ANSI/ASTM D2564

CPVC

ANSI/ASTM F493

Primers

PVC / CPVC

ANSI/ASTM F656

Notes:

1

Refer to Table 4-5 for Allowable Vent and Air-inlet Pipe Sizes and Lengths.

2

PVC venting (exhaust and air-inlet) is not permitted within the Closet/alcove of a Closet/alcove installation.

3

The Air-inlet does not require high temperature pipe material. Check applicable local codes for acceptable materials.

4

ULC S636 PVC is approved for flue gas temperatures up to 149oF (65oC) and must only be used for low temperature
applications. High temperature applications requiring boiler supply water temperatures greater than 140oF (60oC) must
use ULC S636 CPVC, PP or SS.

Model No.

Pipe

Size

Gas

Length

(ft)

Number of Elbows (90’s or 45’s) and Equivalent Feet

1 2 3 4 5 6 7 8 9

All Models

2”

1

NG/LP

100

95

90

85

80

75

70

65

60

55

3”

150

145

140

135

130

125

120

115

110

105

Note:

1

See WARNING below.

Trinity │Installation and Operation Instructions Tx Series

Vent/Air-inlet Pipe Material

Table 4-2 Acceptable Vent and Air-inlet Pipe Material

The use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel®
(polyphenolsulfone) in the exhaust venting system is prohibited. Failure to follow these

instructions may result in property damage, personal injury or death.

Covering non-metallic vent pipe and fittings with thermal insulation is prohibited. Failure
to follow these instructions may result in property damage, personal injury or death.

Vent/Air-inlet Pipe Length Determination
Use Table 4-5 to determine the maximum pipe length that can be used. The table calculates 90º elbows, and 45º

elbows at 5 equivalent feet each.
Example: When using 3” pipe, any Tx boiler can be installed with 150 equivalent feet of air-inlet piping and 150

equivalent feet of exhaust-vent piping. See Table 4-5 for more details.

Table 4-3 Allowable Vent and Air-inlet Pipe Size and Lengths

PVC Exhaust Venting – When using 2” PVC venting, the first seven (7) equivalent feet

of exhaust venting must be approved 2” CPVC or 3” PVC; see exceptions in Table 4-2.

17

Description

Vent

Size

Supplier P/N

Figure

Vent Material
Compatibility

Vent Option

Roof

Wall

IPEX Low Profile
(Flush Mount)

7

2”

196984

4-3(b), 4-5(c)

PVC/CPVC

7





3”

196985 (NTI P/N 84357)

IPEX Concentric
(Wall/Roof)

5,6,7

2”

196005

4-3(c), 4-4(c),
4-5(b), 4-6(b)





3”

196116 (NTI P/N 82666)

197009

DuraVent - PolyPro
Concentric (Wall)

2”

2PPS-HK

4-3(c), 4-5(d)

PVC/CPVC/PPs





3”

3PPS-HK

DuraVent - PolyPro
Concentric (Roof)

2”

2PPS-VK

4-4(c), 4-6(c)





3”

3PPS-VK

Centrotherm – InnoFlue

(Flush Mount)

2”

ISLPT0202

4-3(b), 4-5(c)





3”

ISLPT0303

Centrotherm – InnoFlue
Concentric (Wall)

8

2”

ICWS2413 & ICTC0224

4-3(c), 4-5(d)





3”

ICWS3513 & ICTC0335

ICWT352 & ICTC0335

Centrotherm – InnoFlue
Concentric (Roof)

8

2”

ICRT2439 & ICTC0224

4-4(c), 4-6(c)





3”

ICRT3539 & ICTC0335

Notes:

1

Instructions included with termination kits contain detailed assembly and installation instructions.

2

All factory termination kits are ULC S636 approved.

3

Clearance requirements in this manual supersede those of the instructions included with the vent terminal.

4

Piping MUST be secured to the vent terminal during installation.

5

IPEX Concentric Terminal MUST be cemented together and to the vent pipes during installation.

6

Vent Screens provided with boiler may be used with the IPEX Concentric Vent Kits; otherwise use IPEX vent screens

(2” vent screen P/N 196050; 3" vent screen P/N 196051 – each sold separately).

7

IPEX Low Profile and Concentric kits (excluding p/n 197009) are constructed out of ULC S636 approved PVC; check

with your local authority for the acceptance of PVC as a venting material prior to use.

8

Centrotherm Concentric termination kits must use the applicable “Twin pipe to concentric adapter”, part number

ICTC0224 or ICTC0336.

Tx Series Installation and Operation Instructions │Trinity

Termination Options – Direct Vent Installation

The venting system of the Tx may be terminated using field supplied piping to construct a “Two-Pipe”
termination, see Figures 4-3a, 4-4a, 4-4d, 4-5a, 4-6a and 4-6d; alternatively the venting may be terminated using
a factory kit selected from Table 4-4.

Optional Termination Kits – Direct Vent Installation
Kits certified with the Trinity Tx are listed in Table 4-6 and available from IPEX, DuraVent, Centrotherm and/or

NTI. For more information on System 636 Vent Kits or wholesaler locations contact IPEX directly USA: 1-800­463-9572 or www.IPEXamerica.com │ CAN: 1-866-473-9462 or www.ipexinc.com. For more information on
PolyPro Vent Kits or wholesaler locations contact DuraVent directly 1-800-835-4429 or www.duravent.com. For
more information on InnoFlue Vent Kits or wholesaler locations contact Centrotherm directly at 1-877-434-3432
or www.centrotherm.us.com.

Table 4-4 Optional Vent Termination Kits

Venting Options - Due to potential moisture loading (build-up) along the exterior wall,

sidewall venting may not be the preferred venting option (see Figures 4-4 and 4-6).

18

Figure 4-3(a)

Figure 4-3(b)

Two-pipe Termination (Sidewall)

Low Profile Termination (Sidewall)

Figure 4-3(c)

Concentric Termination (Sidewall)

Exhaust must terminate a
minimum of 18” above Air-inlet
termination; see Figure 4-5(a) for
more details.

Exhaust

Inlet

3” IPEX Low Profile Termination

illustrated; see Figure 4-5(c) for
more details.

Exhaust

Inlet

3” DuraVent Concentric

Termination illustrated, see
Figure 4-5(d) for more details.

Exhaust

Inlet

3” IPEX Concentric Termination

illustrated, see Figure 4-5(b) for
more details.

Exhaust

Inlet

Trinity │Installation and Operation Instructions Tx Series

19

Figure 4-4(a)

Figure 4-4(b)

Two-pipe Termination (Roof)

Two-pipe Termination (Roof-exhaust / Sidewall-inlet)

Figure 4-4(c)

Concentric Termination (Roof)

3” DuraVent Concentric

Termination illustrated, see
Figure 4-6(c) for more details.

Exhaust

Inlet

Exhaust

Inlet

Exhaust must terminate a
minimum of 18” above the Air­inlet termination; see Figure 4­6(a) for more details

3” IPEX Concentric termination

illustrated, see Figure 4-6(b) for
more details.

Exhaust

Inlet

Exhaust

Inlet

Exhaust must terminate a

minimum of 12” above snow

level; see Figure 4-6(d) for more
details

Tx Series Installation and Operation Instructions │Trinity

20

Sidewall Termination Details – Direct Vent Installation

Figure 4-5(a)

Figure 4-5(b)

Two-Pipe Termination (Sidewall)

IPEX Concentric Termination (Sidewall)

Figure 4-5(c)

Figure 4-5(d)

Low Profile Termination (IPEX Illustrated)

PolyPro / InnoFlue Wall Termination

Exhaust

Air-inlet

Min. 12”

above grade
or snow level

Vertical

Min. 18”

Horizontal
4-12” or greater
than 36”

Exhaust

Air-inlet

Vent Screen

Vent pipe piece to
retain vent screen

Gas Vent Directly Below

Keep Free of Obstructions

Exhaust

Air-inlet

Min. 12”

above grade
or snow level

Air-inlet around
perimeter (1-2”
from wall)

Exhaust through
center

Vent Screen

Vent pipe piece to
retain vent screen

Refer to documentation included with termination kit for

complete installation instructions.

Refer to documentation included with termination kit for
complete installation instructions.

Refer to documentation included with termination kit for
complete installation instructions.

Min. 12”

above grade
or snow level

Exhaust

Air-inlet

Exhaust

Air-inlet around

perimeter

Min. 12”

above grade
or snow level

Exhaust center

Air-inlet bottom

Exhaust

Air-inlet

Gas Vent Directly Below

Keep Free of Obstructions

Trinity │Installation and Operation Instructions Tx Series

Tx Series Installation and Operation Instructions │Trinity

21

Roof Termination Details – Direct Vent Installation

Figure 4-6(a)

Figure 4-6(b)

Two-Pipe Termination (Roof)

IPEX Concentric Termination (Roof)

Figure 4-6(c)

Figure 4-6(d)

PolyPro / InnoFlue Roof Termination

Exhaust only Roof Termination

Min. 12”

above grade
or snow level

Vent Screen

Vent pipe piece to
retain vent screen

Exhaust

Air-inlet

Vertical

Min. 18”

Horizontal

4-12” or greater

than 36”

Flashing

Min. 12”

above grade
or snow level

Vent Screen

Vent pipe piece to
retain vent screen

Exhaust center

Air-inlet around

perimeter

Flashing

Refer to documentation included with termination kit for
complete installation instructions.

Refer to documentation included with termination kit for
complete installation instructions.

Min. 12”

above grade

or snow level

Flashing

Exhaust

Air-inlet

Figure illustrates two options for exhaust termination only;
neither vent pipe illustrated is for combustion air-inlet.

Min. 12”

above grade
or snow level

Flashing

Vent pipe piece to
retain vent screen

Vent Screen

Exhaust
Option 1

Exhaust
Option 2



22

Trinity │Installation and Operation Instructions Tx Series

Venting Rules and Guidelines

1. Prevailing Winds: Ensure the vent is located where it will not be exposed to normal prevailing winds.

2. Combustion Air-inlet Contamination: Air for combustion must be drawn from an area free of dust and

contaminants. Combustion air containing chemicals such as chloride, fluoride, bromine or iodine or dust
and debris will cause corrosion damage of the heat exchanger voiding your NTI warranty. Refer to Table 4­1 for a list of corrosive products and contaminants sources to avoid.

3. Vertical Separation: The exhaust must be a minimum of 18” [457 mm] above the air inlet, and the air inlet

must always be a minimum of 12” [305 mm] plus snow allowance above any surface that will support snow.

(Two feet plus snow allowance is highly recommended). Consult your weather office for the maximum
typical snowfall for your region.
Example: New Brunswick Canada - typical maximum snowfall is 19”, thus the inlet must be (12”+19”) =
31” above grade and exhaust must be (31”+18”) = 49” above grade.

4. Horizontal Separation: The horizontal distance between the inlet and exhaust must be a minimum of 4”

[102 mm] center to center.

5. Wall Flashing: Under normal operating conditions this boiler will produce a plume of white gases, and

should be taken into consideration when selecting an adequate location. A 36” [915 mm] diameter stainless,
plastic, or vinyl shield can be used to flash the exterior of the residence.

6. Flue Gas Hazard: Position the vent termination where vapors cannot make accidental contact with people

and pets or damage nearby shrubs and plants.

7. Elbow Extensions: Elbows on outside of wall must be no more than ½” [13 mm] away from the wall.

8. Vent Sloping: All indoor exhaust piping must be on a slope back to the boiler a minimum of ¼” per linear

foot of vent [6.25 mm per linear 305 mm]. For applications where excessive condensation is possible ½” per
linear foot [13 mm per linear 305 mm] is recommended.

9. Vent Supports: Where required Vent and Air-inlet piping shall be secured to the wall for more rigidity. All

interior vent pipe shall be supported a minimum of every 36” [915 mm].

10. Roof Exhaust: In all roof applications the discharge must point away from the pitch of the roof.

11. Roof Flashing: Install adequate flashing where the pipe enters the roof, to prevent water leakage.

12. Rain Cap: Install and seal a rain cap over existing chimney openings, in vacant chimney applications.

13. Venting Below Grade: For installations that exit the wall below grade refer to Figure 4-7.

14. Vent Screens: Install factory supplied vent screens on the outside of the last elbow for both the inlet and

exhaust vent terminal elbows. Install the screen into the female opening of the elbow, and then cut a small
piece of pipe to sandwich the screen into the elbow. NOTE: ensure the small piece of pipe cut, does not
extend past the end of the elbow. Two screens are provided in the package. See Figures 4-5 and 4-6.

15. Condensate Hazard: Do not locate vent over public walkways, driveways or parking lots. Condensate

could drip and freeze resulting in a slip hazard or damage to vehicles and machinery.

16. Warning Plate: For Sidewall Venting, install the warning plate “Gas Vent Directly Below”, directly above

(within 4 ft [1.22 m] vertically) the location of the air-inlet pipe, so it is visible from at least 8 ft [2.4 m]
away. See Figure 4-5.

17. Wall Thickness: Direct vent terminations are designed to work with any standard wall thickness.

Installation guidelines for min/max wall thickness are as follows: Min.= 1” [25mm], Max.= 60” [1.52 m].

18. Venting Options: Due to potential moisture loading (build-up) along the exterior wall, sidewall venting

may not be the preferred venting option. Refer to Figures 4-4 and 4-6 for roof top venting options.

23

Figure 4-7 Venting Below Grade

For installations that exit the wall below grade:

1. Excavate site to a point below where the pipes

are to exit as shown.

2. Ensure the wall is fully sealed where the pipes

penetrate.

3. The Vent/Air-inlet piping MUST be secured to

the side of the building above grade, as shown,
to provide rigidity.

4. Optional mounting bracket PN. 82075 for

securing the exhaust pipes (only applicable for
3” PVC/CPVC venting).

5. Ensure that the Vent/Air-inlet clearances are

maintained, see Section 5.0 for details.

Figure 4-8 Outdoor Horizontal Venting

Vent piping outside the Building is permitted under
the following conditions:

1. The maximum length outside the building is 20

feet [6.1 m]. Note that outdoor length must be
included in the overall vent length calculation.

2. All normal termination clearances are maintained.

3. The pipe is supported every 24” [610 mm].

4. The exhaust and inlet are sloped back to the boiler

½” elevation for every linear foot [13 mm for
every linear 305 mm].

Figure 4-9 Existing Chimney Chase Way

It is permissible to use an existing chimney as a chase
way to run the Vent/Air-inlet piping as long as:

1. The chimney is not being used by any other

boiler.

2. Flue gases don’t enter the vacant chimney.

3. Only Trinity certified venting materials are used,

see Section 4.0.

4. Vent lengths are within the maximums specified.

5. The top of the chimney is capped and the

Vent/Air-inlet pipes are flashed to prevent
leakage into the vacant chimney.

Air-Inlet

Existing
Chimney
(used as a
chase way)

Chimney
Cap

Exhaust Vent

Exhaust Vent Min.

18” [457 mm]

above air-inlet

Air-Inlet

Min. 12” [305 mm]

above roof and
snow level

Supports every

24” [610 mm]

12” [305 mm] plus snow

allowance above grade

Air-Inlet

Maximum of 20 ft
[6.1 m] is permitted
for piping outside a
building.

Exhaust
Vent

Gas Vent Directly Below

Keep Free of Obstructions

Exhaust

Air-inlet

Wall Brackets

Tx Series Installation and Operation Instructions │Trinity

24

Clearances to Air-Inlet Termination

Canada 1

USA 2

Min. Distance

Min. Distance

A

Above grade/roofline and snow level 8

12 in.

305 mm

12 in.

305 mm

B

Above roof line - Concentric Vent

6, 11, 13

24 in.

610 mm

24 in.

610 mm

C

To exhaust vent from any other boiler

36 in.

915 mm

12 in.

305 mm

Clearances to Exhaust Vent Termination

Min. Distance

Min. Distance

D

Minimum vertical separation above air inlet 9

18 in.

457 mm

18 in.

457 mm

E

Minimum horizontal separation from air inlet 3

4 in.

102 mm

4 in.

102 mm

F

Window, door or building opening

36 in.

915 mm

12 in.

305 mm

G

To combustion air inlet from any other boiler

36 in.

915 mm

12 in.

305 mm

H

Non-mechanical air supply inlet to building

36 in.

915 mm

12 in.

305 mm

I

Mechanical air supply inlet to building 4

6 ft.

1.83 m

3 ft.

915 mm

J

Soffit, overhang, eave or parapet

24 in.

610 mm

24 in.

610 mm

K

Soffit vent or vent opening in an overhang, eave or parapet

6 ft.

1.83 m

6 ft.

1.83 m

L

Outside corner 10

- - -

-

M

Inside corner of an L-shaped structure (including walls and fences)

36 in.

915 mm

36 in.

915 mm

N

Electric meters, gas meters, regulators and relief equipment

6 ft.

1.83 m

4 ft.

1.22 m

P

Each side of center line above or below meters, regulators and relief devices 5

36 in.

915 mm

36 in.

915 mm

Q

Above a paved sidewalk, driveway, or parking lot on public property if adjacent 12

7 ft.

2.13 m

7 ft.

2.13 m

R

Above a sidewalk, driveway, or parking lot on public property

X X X

X

S

Above a sidewalk, driveway on private property between / serving both dwellings

X X X

X

T

Under a concrete veranda, porch, deck, or balcony 7

24 in.

610 mm

24 in.

610 mm

U

Above, under or near exterior stairs

X X X

X

V

Into a canopy or carport

X X X

X

Notes:

1 - Canadian installations must comply with the current CSA B149.1 Natural Gas and Propane Installation Code and local

building codes.
2 - US installations must comply with current ANSI Z223.1/ NFPA 54 National Fuel Gas Code and local building codes.
3 - Horizontal separation center-to-center (c.c.) 4”-12” (102-305 mm).

4 - For US installations, an exhaust vent may be 3 ft above a mechanical air supply inlet if within 10 ft. [3 m] horizontally.
5 - Horizontal clearance must be observed up to a height of 15 ft. [4.6 m] above/below the meter, regulator, or relief devices.
6 - Concentric Vent must protrude from the roof precisely 24” [610 mm] measuring from the terminal end-cap vanes.
7 - Permitted if veranda, porch, deck, or balcony is made of concrete and a minimum of two sides are fully open beneath.
8 - 24” is the recommended snow level allowance above grade/roofline or any surface that will support snow, debris, or ice

(i.e. for roof venting clearances - roofline and snow level). If living in a snowfall region, consult your local weather

office for the maximum typical snowfall for your area.

9 - Note that the vent must maintain a minimum vertical distance above the air-inlet. Example: Vent height = 18” (457

mm) above air inlet + 12” (305 mm) for air inlet above grade/roof line and snow level = 30” (762 mm) above grade and

snow level.

10 - Clearances to an outside corner to be in accordance with local installation codes.
11 - In Canada, concentric vent materials are subject to approval by local inspectors. See Termination Kits in Section 4.0.

12 - Above public walkways, driveways or parking lots if adjacent to it and condensate cannot drip, freeze, or create a hazard.
13 - Contact the manufacturer for special exemptions relating to multiple boiler installations using concentric vents.

Trinity │Installation and Operation Instructions Tx Series

5.0 VENT/AIR-INLET TERMINATION CLEARANCES

instructions detailed in this section are a combination of Trinity Tx specific and National Gas Code restrictions.
Compliance alone doesn’t insure a satisfactory installation as good common sense must also be applied. Failure
to follow these instructions may result in fire, property damage, serious injury or death.

Table 5-1 Termination Clearances Quick Reference Table (See Figures 5-1 and 5-2)

The quick reference table below is to be read in conjunction with the numbered notes as
indicated, Figures 5-1 and 5-2, and the Venting Rules and Guidelines in Section 4.0. The

25

G – Letter represents a specific Termination Position. Refer to Table 5-1 for corresponding termination clearances.

Concentric Vent
Termination

Q

Two-Pipe
Termination

F

Clearance “Q”
Adjacent to Public
Walkway or Driveway
Minimum 7ft [2.13 m]

G

Clearances “F” and “G”
Canada – Minimum 3 ft [915 mm]
The US – Minimum 1 ft [305 mm]

Tx Series Installation and Operation Instructions │Trinity

Figure 5-1 Termination Clearance Quick Reference Diagram (See Table 5-1)

Illustrations of Termination Clearances

Figure 5-2 Sidewall Termination (See Table 5-1)

26

Trinity │Installation and Operation Instructions Tx Series

may result in venting or boiler component failure resulting in flue gas spillage leading to property damage,
serious injury or death.

result in fire, property damage, serious injury or death.

Removing an Existing Boiler from Common Venting System

emissions into the surrounding air resulting in serious injury or death.

connected to it. Instructions have been provided on how to remove the existing boiler and how to resize the
remaining venting system. Failure to follow these instructions may result in property damage, serious injury or
death.

Upon removal of an existing boiler, the following steps shall be followed for each boiler remaining in the
common venting system; prior to commencing this procedure, shutdown all boilers remaining in the common
venting system.

Steps to Removing an Existing Boiler:

1. Seal any unused openings in the common venting system.

2. Visually inspect the venting system for proper size and horizontal pitch. Verify that there is no blockage,

restriction, leakage, corrosion or other deficiencies which could cause an unsafe condition.

3. Insofar as is practical, close fireplace dampers, all building doors and windows and all doors between the

space in which the boilers remaining connected to the common venting system are located and other spaces
of the building. Turn on clothes dryers and any boiler not connected to the common venting system. Turn on
any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed. Do
not operate a summer exhaust fan.

4. Place in operation the boiler being inspected. Follow the applicable lighting instructions. Adjust thermostat

so boiler will operate continuously.

5. Test for spillage at the draft hood relief opening after 5 minutes of main burner operation. Use the flame of a

match or candle, or smoke from a cigarette, cigar or pipe.

6. After it has been determined that each boiler remaining connected to the common venting system properly

vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other
gas burning boiler to their previous condition of use.

7. Any improper operation of the common venting system should be corrected so the installation conforms to

the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or CAN/CSA B149.1, Natural Gas and Propane
Installation Code. When resizing any portion of the common venting system, the common venting system
should be resized to approach the minimum size as determined using the appropriate tables in Part 11 of the
National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or CAN/CSA B149.1, Natural Gas and Propane
Installation Code.

Extra precaution must be taken to adequately support the weight of the Vent/Air-inlet
piping in applications using roof-top terminations. Failure to follow these instructions

Under no circumstances may an existing chimney or chase-way be used to vent or
provide combustion intake air to a Trinity Tx. Failure to follow these instructions will

Do not install the Trinity Tx into a common venting system with any other boiler. Failure
to comply with this warning will cause flue gas spillage and leech carbon monoxide

When an existing boiler is removed from a common venting system, the common
venting system is likely to be too large for proper venting of the remaining boilers

27

Tx Series Installation and Operation Instructions │Trinity

6.0 CONDENSATE DRAIN

This unit produces liquid condensate in the heat exchanger and venting system as a product of combustion.
Steps must be taken to ensure condensate does not collect in the venting system; therefore, all exhaust piping
must slope back to the boiler a minimum 1/4” per linear foot of vent. Condensate must be drained from the unit
into a household drain.

condensate must be neutralized prior to entering a drain).
The following are important notes that must be taken into consideration when constructing the condensate drain

system (See Condensate Trap Installation Instructions for further details):

 DO NOT install condensate lines outside. A frozen or blocked drain will cause the condensate to back-up

and leak. This may result in damage to boiler components resulting in a no heat condition; property damage
may also occur.

 NEVER use copper, steel, or galvanized piping in the construction of the condensate system (condensate is

very corrosive and will corrode most metals).

 When a condensate pump is used or required, select a pump that is designed for residential furnaces.

Condensate Trap Installation Instructions (see Figure 6-1)

(Note: the Condensate Trap is factory supplied with the boiler and must be field installed)

1. Attach Corrugated Outlet Tube – Remove the Outlet Retaining Nut and Outlet Gasket and slide

components onto the Corrugated Outlet Tube – note orientation (gasket should be positioned
approximately 1/8” from the edge of the outlet tube – see Figure 6-1). Press the Corrugated Outlet Tube
into the Condensate Trap Outlet and firmly hand-tighten the Outlet Retaining Nut.

2. Attach to Boiler Condensate Drain (A) – Ensure the Ball-float is placed inside the condensate trap,

position the Inlet Gasket in between the condensate trap and boiler condensate outlet (See Figure 6-1).

3. Attach to Boiler Condensate Drain (B) – Secure the Condensate Trap into place by firmly hand-

tightening the Inlet Retaining Nut.

4. Outlet to Drain – Route the condensate from the Corrugated Outlet Tube to a household drain, condensate

pump or neutralizer (check with your local authority regarding the disposal of condensate).

Failure to install the condensate trap properly will result in flue gas spillage and leeching of carbon monoxide
emissions into the surroundings resulting in serious injury or death.

Check with your municipality, or local gas company to determine if the disposal of
combustion condensate is permitted in your area (e.g. in the State of Massachusetts the

Carefully follow the above instructions and the accompanying figure – check to ensure
the condensate trap is secure to the bottom of the boiler and that no strain is placed on it.

28

Figure 6-1 Condensate Drain Piping

Inlet Retaining Nut

firmly tightened



Boiler Condensate Drain

Outlet Gasket

Ball-float



Inlet Gasket

Outlet

Corrugated Outlet Tube

Outlet Retaining Nut

Outlet Gasket

Inlet

Cleanout Cap

Condensate Trap



Corrugated Outlet Tube routed to household
drain, condensate pump or neutralizer (no strain
applied on tubing or condensate drain assembly)



Trinity │Installation and Operation Instructions Tx Series

29

Model

Kit Number

Orifice Number

Tx51

84867-1

3.5

Tx81

84867-2

3.8

Tx101

84867-3

4.2

Tx151, Tx151C

84867-4

5.05

Tx Series Installation and Operation Instructions │Trinity

7.0 INSTALLING GAS PIPING

Conversion Kit (see Table 7-1) must be installed prior to installing the gas piping to the boiler. Failure to
properly convert the unit to operate with Propane may result in property damage, serious injury or death.

Codes as they may require boilers fueled with LP gas to be provided with an approved means of removing
unburned gases from the room. Failure to follow these instructions may result in serious injury or death.

Table 7-1 Natural to LP Propane Conversion Kit

Installation

Refer to the current National Fuel Gas Code ANSI Z223.1/NFPA 54 or CAN/CGA B149.1 installation codes,
and local codes for gas piping requirements and sizing. Pipe size running to the unit depends on:

 Length of pipe.
 Number of fittings.
 Type of gas.
 Maximum input requirement of all gas boilers in the residence.

Ensure that:

 The gas line connection to the boiler does not apply any weight to the gas valve. NTI recommends using

approved flexible gas piping (if acceptable by local codes) to connect the boiler to the gas supply (See
Figure 7-1 for details).

 You plan the installation so the piping does not interfere with the vent pipe, or the removal of the valve,

burner, and serviceable components.

 The Boiler is installed such that the gas ignition system components are protected from water (dripping,

spraying, rain etc.) during installation and servicing.

 The gas piping is large enough for all the gas appliances in the home. No appreciable drop in line pressure

should occur when any unit (or combination of units) lights or runs. Use common gas-line sizing practices.

 Always use a pipe-threading compound that is resistant to Propane (LP) gas solvent action. Apply sparingly

to all male threads, starting at two threads from the end. Over doping or applying dope to the female end,
can result in a blocked gas line.

 DO NOT TIGHTEN FITTINGS WITHOUT SUPPORTING THE GAS VALVE as damage to the valve or

blower motor can occur.

 Install a manual “Equipment Shut-Off Valve” as shown in Figure 7-1. Valve must be listed by a nationally

recognized testing laboratory.

 The gas line piping can safely be removed from the boiler for servicing, by strategically placing the gas line

shutoff and union; see example in Figure 7-1.

 All gas piping, including gas components in the boiler, are checked for leaks using a “Bubble Test”, prior to

operating the boiler.

gas valve could occur resulting in fire, property damage, serious injury or death.

The Trinity Tx is factory equipped to operate with Natural Gas, the installation of a
conversion kit is required prior to operating with Propane Gas. The Natural to LP

Liquefied Petroleum (LP) propane gas is heavier than air. Do not install the boiler in a pit
or similar location that will permit heavier than air gas to collect. Check with Local

Strain on the gas valve and fittings may result in vibration, premature component failure
and leakage and may result in a fire, explosion, property damage, serious injury or death.

Do not use an open flame to test for gas leaks. Failure to follow these instructions may
result in fire, property damage, serious injury or death.

When performing a pressure test on the gas line piping, be sure the boiler is disconnected
or isolated if the test pressure is expected to exceed 1/2 PSI (14” w.c.), as damage to the

30

Figure 7-1 Gas Line Connection (Typical)

Test all gas piping, internal and external to the boiler, for leaks. Failure to follow
these instructions may result in fire, property damage, serious injury or death.

Manual Gas Shutoff Valve

Should overheating occur or the gas
supply fail to shutoff, close the Manual
Gas Shutoff Valve to the boiler.

Union

Flexible Gas Line Piping

Recommended to eliminate strain on the
boiler gas components (only use if
acceptable by local codes).

Drip Leg

Rigid Gas Line Piping

Use only rigid gas line piping within the
boiler cabinet. Rigid piping must
protrude beyond the outside of the
cabinet wall.

Trinity │Installation and Operation Instructions Tx Series

Tx Series Installation and Operation Instructions │Trinity

31

8.0 LIGHTING THE BOILER

Before Start-up refer to Mandatory Pre-commissioning Procedure for Plastic Venting
in Section 4.0. Failure to follow these instructions can result in explosions, injury or death.

Prior to turning the gas supply on and lighting the boiler, ensure all aspects of the
installation are complete and in conformance with the instructions provided in this

manual, including the Vent/Air-inlet, Condensate Drain, and System Water Piping.
Failure to precisely follow these instructions will cause a fire or explosion resulting in property damage, serious
injury or death.

Do not store or use gasoline or other flammable vapors & liquids in the vicinity of this or

any other boiler. Failure to follow instructions could result in explosion causing property

damage, serious injury or death.

If you do not follow these instructions exactly, a fire or explosion may result causing

property damage, serious injury or death.

Should overheating occur or the gas supply fail to shutoff, close the Manual Gas Shutoff

Valve to the boiler. Failure to follow instructions could result in explosion causing
property damage, serious injury or death.

FOR YOUR SAFETY, READ BEFORE OPERATING_

A) This boiler does not have a pilot. It is equipped with an ignition device which automatically lights the

burner. Do not try to light the burner by hand.

B) BEFORE OPERATING smell all around the boiler area for gas. Be sure to smell next to the floor
because some gas is heavier than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS:

• Do not try to light any boiler.

• Do not touch any electric switch.

• Do not use any phone in your building.

• Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.

• If you cannot reach your gas supplier, call the fire department.

C) Use only your hand to turn the gas “shutoff” valve. Never use tools. If the handle will not turn by hand,

don't try to repair it, call a qualified service technician. Force or attempted repair may result in a fire or
explosion.

D) Do not use this boiler if any part has been under water. Immediately call a qualified service technician
to inspect the boiler and to replace any part of the control system and any gas control which has been
under water.

1. STOP! Read the safety information above very carefully.

2. Set the thermostat to lowest setting. Turn off all electric power to the boiler.

3. This boiler does not have a pilot. It is equipped with an ignition device which automatically lights the

burner. Do not try to light the burner by hand.

4. Turn the manual gas valve to the OFF position. Remove front access panel.

5. Wait five (5) minutes to clear out any gas. Then smell for gas, including near the floor. If you smell gas,

STOP! Follow “B” in the safety information above. If you don't smell gas, go to the next step.

6. Turn the manual gas valve ON. Wait an additional five (5) minutes smelling for gas.

7. Replace the front access panel.

8. Set thermostat to highest setting. Turn on all electric power to the boiler.

9. Ignition sequence is automatic. Combustion will occur after a brief fan purge.

10. If ignition does not occur, follow the instructions “To Turn Off Gas To Boiler” and call your service

technician or gas supplier.

1. STOP! Read the safety information above very carefully.

2. Turn off all electric power to the boiler

3. Turn the manual gas valve to the OFF position

OPERATING INSTRUCTIONS_

TO TURN OFF GAS TO THE BOILER_

32

Trinity │Installation and Operation Instructions Tx Series

 Ensure the boiler is wired in accordance with this manual.
 Ensure the gas shutoff valve is turned on, and that the gas system has been fully tested for leaks.
 Ensure the system is completely filled with water, and that ALL the air is purged out.
 Ensure the Vent and Air-inlet piping is completely installed in accordance with this manual.

Plastic Venting in Section 4.0. Failure to follow these instructions can result in explosion, serious injury or death.

Initial Start-Up

Each time the power is turned on to the boiler, the control will go through a “de-air” sequence designed to
purge air from the boiler. The de-air sequence takes 7 minutes to execute, during which time the circulators
will be operating in a cyclical manner and the burner will not attempt to function. Once the de-air sequence
has been executed at least once, subsequent de-air sequences can be bypassed by holding the “OK” button
until “de-Air” is no longer displayed on the screen; see Section 17.0 for more details.

1. Turn on power to the Trinity Tx and turn-up the Thermostat(s). The boiler should run through a purge, and

combustion should occur. (The control system has a built-in ignition retry, allowing the system to try at least
three times, before locking-out.)

2. With the unit operating at full capacity, verify that the gas line pressure is 4-10.5 inches w.c. for Natural gas,

and 9-13 inches w.c. for Propane (See Section 9.0 for details).

3. Using an appropriate Oxygen (O2) or Carbon Dioxide (CO2) analyzer, take a sample of the flue gas. The

sample must fall within the acceptable ranges for CO2 (see Section 9.0 for details).

4. Perform at least three ignitions in succession to ensure proper operation.

5. After the three successive ignitions, unplug the flame sensor and allow the unit to cycle again. The flame

safety system will allow the unit to go through 5 ignition cycles before going to “Loc 1”. Once you have
confirmed this behavior, reinstall the wire on the flame sensor, press the reset button and reconfirm proper
ignition.

on the right-hand side while the power is on; this device is used for spark ignition and produces 20,000 Volts
potential which would result in an EXTREME ELECTRICAL SHOCK possibly causing serious injury or death.

burner is rough or erratic. Failure to follow these instructions may result in serious injury or death.

Re-lighting Unit

1. Stop and read these instructions very carefully.

2. Set the thermostat to the lowest setting, and then turn off all power to the boiler.

3. This boiler does not have a pilot. It is equipped with an ignition device that automatically lights the burner.

Do not try to light the burner by hand.

4. Turn the gas shutoff valve to the off position, and then remove the front cover.

5. Wait five (5) minutes to clear out any gas. Then check for gas, including near the floor. If you smell gas

“Stop” and follow “B” above (see FOR YOUR SAFETY, READ BEFORE OPERATING). If you don’t
detect any gas proceed to the next step.

6. Turn the gas shutoff valve to the on position, wait an addition five (5) minutes and check for gas.

7. Replace the front cover.

8. Set the thermostat to the highest setting, and then turn on all power to the boiler.

9. Ignition sequence is automatic, combustion will occur after a brief fan purge. Ignition will retry 3 times.

10. If ignition does not occur, “Turn off the gas and electricity to the boiler” and contact a qualified service

technician, or gas supplier.

The initial lighting of the boiler must be performed by a licensed Gas Technician.
Failure to follow instructions may result in property damage, serious injury or death.

Allow primers/cements to cure for 8 hours prior to Start-up. If curing time is less than 8
hours, first perform Steps 2 through 6 of Mandatory Pre-commissioning Procedure for

The flame sensor is located in the burner door on the left-hand side; it is the electrode
without the spade terminal for the ground wire. DO NOT remove (or touch) the cable

If the unit fails to light consistently and smoothly, contact NTI for technical assistance at
1-800-688-2575. Never allow the boiler to operate if the ignition or operation of the

33

Tx Series Installation and Operation Instructions │Trinity

Turning Off the Boiler

1. Set the thermostat to the lowest setting, and then turn off all power to the boiler.

2. Turn the gas shutoff valve to the off position.

34

Model

Gas

Line Pressure (inches w.c.)

CO2 (%)*

CO
(ppm)
Max.*

Nominal/Desired

Min.

Max.

Min.

Max.

Tx51-151(C)

Natural 7 4

10.5

9.0

9.6

175

Tx51

Propane

11

8

13

10.4

11.0

Tx81-151(C)

10.0

10.6

Model

Gas

Appliance

Number

Min. Modulation Rate

(RPM)

Max. Modulation Rate

(RPM)

Tx51

NG 1 1500

4740

LP 6 1500

4500

Tx81

NG & LP 2 1500

5700

Tx101

NG & LP 3 1500

5820

Tx151

NG & LP 4 1620

6540

Tx151C

NG & LP 5 1620

6540

Trinity │Installation and Operation Instructions Tx Series

9.0 GAS VALVE AND BURNER SET-UP

failure, property damage, serious injury or death.

Gas Line Pressure

The boiler gas valve is equipped with a line pressure test port; see Figure 9-1. Use the following procedure to
measure the gas line pressure to the boiler to ensure if falls within the range given in Table 9-1:

1. Turn the supply of gas to the boiler off.

2. Open the bleed screw of the line pressure test port approximately 1-1/2 turns. This port is directly

connected to the gas line feeding the boiler. See Figure 9-1.

3. Force 1/4 ID tubing over the housing of the line pressure test port; install the other end of the tubing to an

appropriate line pressure test gauge or manometer. Ensure both ends of the tubing make a tight connection.

4. Open the supply of gas to the boiler and check for gas leaks.

5. Observe the line pressure under static conditions and compare it to Table 9-1. The pressure will be greatest

under static conditions.

6. With all other gas appliances in the application running, operate the burner to the maximum firing rate (See

Table 9-2) and compare the observed line pressure with Table 9-1. The pressure will be lowest during the
maximum flow of gas.

7. Adjust the gas line pressure to ensure the parameters in Table 9-1 are attained under all conditions (See

NOTICE below). If possible adjust the line pressure to the "Nominal/Desired" value listed in Table 9-1,
while the unit is operating at the maximum modulation rate, see Table 9-2.

8. Continue observing the gas line pressure until the completion of the combustion analyses, in case

adjustments need to be made.

9. Complete pressure testing, and then return the bleed screw of the Line Pressure Test Port to the closed

position.

gas valve influence or be used to adjust the gas line pressure.

Table 9-1 Line Pressure and Combustion Parameters

Set-up of the Trinity Tx gas valve must be performed by a licensed Gas Technician.
Failure to perform the set-up correctly may result in incorrect operation, component

The line pressure is a function of the gas supply and is affected solely by field provided
parameters such as line size and regulator settings. Under no circumstances can the boiler

Failure to close the bleed screw of the Line Pressure Test Port will cause a severe leakage
of gas, resulting in a fire or explosion causing property damage, serious injury or death.

*Note: Observe the combustion products with the burner operating at the maximum modulation rate, CO2 and CO values will
be lower at minimum modulation rate.

Table 9-2 Minimum and Maximum Modulation Rates

Tx Series Installation and Operation Instructions │Trinity

35

Throttle/Input Adjustment Screw

Increase gas
Turn Counter Clockwise

Decrease gas
Turn Clockwise

Carbon Monoxide - Never leave the unit operating while producing Carbon Monoxide
(CO) concentrations in excess of 175ppm. Failure to follow this warning may result in

serious injury or death.

operation resulting in fire, explosion, property damage or death.

CO. Adjustments may only be performed if the gas line pressure is maintained above minimum levels
throughout the duration of the test, see Table 9-1. Failure to follow these instructions may result in serious
injury or death.

Adjustment

Throttle / Input Screw Adjustments - The boiler is equipped with a Throttle/Input Adjustment Screw, located
on the Gas Valve. It is used to adjust the flow of gas leaving the gas valve entering the Venturi and then the
combustion air stream. Turn the Throttle screw in (clockwise) to reduce the flow of gas, make combustion
leaner, and reduce the concentration of CO2 in the flue gases. Turn the Throttle screw out (counterclockwise) to
increase the CO2 level and flow of gas in the combustion air stream. Typical adjustment required is 0-1/2 full
turns in or out from the factory setting. See Figure 9-1 for Throttle screw location and Table 9-1 for appropriate
CO2 levels.

Combustion Calibration - To calibrate burner operation, perform the following procedure using a calibrated
combustion analyzer capable of measuring CO2 and CO from Natural and Propane Gas burning boilers:

1. Operate the unit at the maximum modulation rate, see Table 9-2.

2. Ensure the gas line pressure is maintained within tolerance, see Table 9-1.

3. While at the maximum modulation rate, measure the CO2 and CO; adjust as necessary, using the Throttle

Screw, to be within the limits listed in Table 9-1.

4. Operate the unit at the minimum modulation rate (Table 9-2). Ensure the combustion remains smooth and

CO2 and CO values are lower than the values obtained during maximum modulation (Table 9-1). If not, do
not adjust further, contact NTI for assistance.

Flue Gas Analysis and Adjustment

Each Trinity Tx is factory set to operate with Natural Gas, for boilers field converted to operate with Propane
Gas, a flue gas analysis and adjustment is mandatory. See Table 7-1 and Propane conversion instructions.

consumption, reduced component life, heat exchanger combustion deposits, and general unsafe operation.
Failure to follow these instructions may result in serious injury or death.

Analysis – Perform flue gas analysis, and adjust throttle/input screw as required until CO2 and CO levels are
within acceptable limits.

Manifold Pressure - DO NOT adjust or measure the Manifold Pressure of the boiler.
Correct manifold pressure is factory set. Field adjustment could result in improper burner

Adjustments to the Throttle / Input Screw may only be made by a qualified gas
technician, while using a calibrated combustion analyzer capable of measuring CO2 and

Failure to perform the flue gas analysis and adjustment detailed in this section may result
in erratic and unreliable burner operation, leading to reduced efficiency, increased fuel

36

Figure 9-1 Tx Gas Valve and Venturi Assembly

Gas Valve

Line Pressure

Test Port

DO NOT Adjust

Throttle / Input
Adjustment Screw

Manifold Pressure
Test Port

Venturi

Trinity │Installation and Operation Instructions Tx Series

Tx Series Installation and Operation Instructions │Trinity

37

Table 10-1 Boiler System Cleansers and Corrosion Inhibitors

Application

Fernox Product

NTI Part #

Description

Boiler Water Treatment

F1 Protector

83448

Corrosion inhibitor.

Cleanser for new and old systems

F3 Cleaner

83449

Removes flux, grease and carbon residue.

Cleanser for Retrofits

DS-40 System Cleaner

83450

Removes heavy limescale and sludge deposits.

10.0 BOILER AND HEATING SYSTEM PIPING

The heat exchanger of the Trinity boiler is designed to attain the highest level of heat transfer in a compact
design. To accomplish this, the heating water flows through a series of fin shaped tubes, designed to maximize
the heat transfer area. To maintain the efficient and reliable operation of the heat exchanger, and to avoid heat
exchanger failure, it is critical to ensure the rules and guidelines in this section are followed.

Failure to follow the instructions provided in this section will void the NTI warranty and
may result in property damage, fire, serious injury or death.

Boiler System Preparation

Prior to connecting plumbing to the boiler, flush the entire system to ensure it is free of sediment, flux, solder,
scale, debris or other impurities that may be harmful to the system and boiler. During the assembly of the
heating system, it is important to keep the inside of the piping free of any debris including construction and
copper dust, sand and dirt.

For retrofits, all system piping, including radiators, must be cleansed of build-up including sludge and scale. All
systems, old and new, must be cleansed to remove flux, grease and carbon residue; NTI recommends cleaning
the boiler system with “Fernox F3 Cleaner”. For retrofit applications with heavy limescale and sludge deposits, a
heavier duty cleaner may be required; NTI recommends the use of “Fernox DS-40 System Cleaner”. For
information on performing the cleaning, follow the instructions included with the applicable Fernox Cleaner. See
Table 10-1 for a list of recommended boiler system cleaning and treatment products.

Failure to rid the heating system of the contaminants listed above will void your NTI
warranty and may result in premature heat exchanger failure and property damage.

Boiler Water

Pressure - Trinity boilers are intended solely for use in pressurized closed-loop heating systems operating with a
minimum pressure of 12 PSI at the boiler outlet. To obtain the minimum system design pressure, follow the
piping diagrams illustrated in this section.

Oxygen Elimination - This boiler may only be installed in a pressurized closed-loop heating system, free of air
and other impurities. To avoid the presence of oxygen, ensure all of the air is removed from the system during
commissioning via strategically placed, adequately sized air-removal devices; located throughout the heating
system. See figures in this section detailing the location of the primary air-removal device required for the
boiler. Immediately repair any leaks in the system plumbing to avoid the addition of make-up water; make-up
water provides a source of oxygen and minerals that may lead to heat exchanger failure. Failure to follow these
instructions will result in poor performance, unnecessary wear of system components and premature failure.

The Trinity Tx is not approved for operation in an “open system”, thus it cannot be used
for direct potable water heating or process heating of any kind.

38

Trinity │Installation and Operation Instructions Tx Series

Water Chemistry – The installer of the Trinity Tx boiler must consider the condition of the water in the heating

system. Ensure the condition of the boiler water falls within the following parameters:

 Conductivity – 100 to 300µS/cm (at 25ºC); [TDS 50 to 150ppm or Total Hardness 3 to 9grains/USgal.]
 PH – between 7.5 and 9.5.
 Chloride – less than 125mg/l.
 Iron – less than 0.5mg/l.
 Copper – less than 0.1mg/l.

Treatment - Boiler water that falls outside of the conditions listed above must be treated with a corrosion
inhibitor. For information on performing the treatment, follow the instructions included with the corrosion
inhibitor. See Table 10-1 for a list of recommended boiler system cleaners and corrosion inhibitors.

To maintain protection, the level of corrosion inhibitor must be monitored periodically
for the correct concentration.

Anti-freeze - For systems requiring freeze protection, use only inhibited propylene glycol, specially formulated
for hydronic heating systems; use of other types of antifreeze may be harmful to the system and will void the
warranty. Note: the use of glycol may reduce the usable output capacity of the boiler, thus requiring the unit to
be “down-fired” by limiting the maximum operating capacity and/or the maximum water temperature. NTI
recommends against exceeding 35% concentration of glycol.

Near Boiler Plumbing (Central Heating)

Pressure Relief Valve - A Pressure Relief Valve is factory supplied with each unit. Trinity Tx boilers have a
maximum allowable operating pressure of 45PSI.

The pressure relief valve must be installed at the boiler outlet and in the vertical position, as shown in Figure 10­1, with the drain pipe outlet exiting the side of the pressure relief valve horizontally and elbowing downward.

Pressure Gauge – Trinity Tx units come with a factory supplied Pressure Gauge. The pressure gauge must be
installed at the boiler outlet prior to any circulators. See Figure 10-1.

Low Water Cutoff (LWCO) – Trinity Tx boilers are provided with a factory installed Water Pressure Sensor.
The sensor provides a readout on the display indicating the inlet water pressure to the boiler; in the event the
pressure drops below 7 PSI, the control will go to a blocking error “Err 59”, inhibiting burner operation. Where
required by the Authority having jurisdiction, an external LWCO may have to be installed.

DO NOT use inhibited glycol with non-compatible boiler inhibitors. Non-compatible
inhibitors may counteract each other rendering them ineffective.

If installed in the incorrect orientation (horizontally with drain pipe out the bottom) the
relief valve may not function properly resulting in property damage or personal injury.

Ensure the discharge of the pressure relief is piped to a location where the steam or water
will not cause property damage or serious injury.

39

Figure 10-1(a)

Figure 10-1(b)

Tx51-151 (non-Combi) – Fitting Identification

Tx51-151 (non-Combi) – CH Piping

Figure 10-1(c)

Figure 10-1(d)

Tx151C (Combi) – Fitting Identification

Tx151C (Combi) – CH Piping

Outlet

Inlet

Pressure

Relief Valve

Pressure Gauge

¾” Brass Street Tee

(factory supplied)

1x1x3/4” Brass Tee

(factory supplied)

30psi Relief Valve

(factory supplied)

Boiler Inlet

Boiler Outlet

Primary Loop

(factory supplied)

Gasket

(factory supplied)

30psi Relief Valve

(factory supplied)

Boiler Inlet

Boiler Outlet

DHW Outlet

DHW Inlet

Pressure Gauge

(factory supplied)

Outlet

Inlet

Pressure

Relief Valve

Pressure Gauge

Tx Series Installation and Operation Instructions │Trinity

40

Table 10-2 Minimum Flow Rate Requirements

Model

Flow (US gpm)

Model

Flow (US gpm)

Tx51

1.9

Tx101

4

Tx81

3.3

Tx151

6

Factory Supplied

Field Supplied Components

 Pressure Relief Valve

 Boiler Loop Circulator (factory supplied with model Tx151C)

 Pressure Gauge

 DHW Loop Circulator (factory supplied with model Tx151C)

 Boiler Loop Circulator (model

Tx151C only)

 Central Heat (CH) Loop Circulator(s)

 Primary Loop Manifold

(model Tx151C only)

 Central Air Removal Devices (i.e. Micro Bubbler or Air-Scoop)

 Pressure Regulating “Fill Valve”

 Backflow Preventer

 Expansion Tank

Trinity │Installation and Operation Instructions Tx Series

Boiler System Plumbing

The Trinity Tx boiler uses a low mass heat exchanger that requires a minimum rate of forced water circulation
any time the burner is operating (See Table 10-2 for minimum flow rate requirements). To ensure the minimum
flow rate is attained, NTI strongly recommends installing the boiler in a “Primary/Secondary” plumbing
configuration utilizing “Closely Spaced Tees” or a “Low Loss Header” to de-couple the Boiler-Primary loop
from the System-Secondary loop(s). See the examples of Primary/Secondary Loop configurations in Figures 10­3 through 10-6.

System Components – As a minimum, a properly installed system will include the following major components
identified in Table 10-3.

Table 10-3 System Major Component Checklist

Circulating Pumps – Trinity Tx boilers are equipped with three 120VAC pump outputs:

1. DHW Pump - operates during a Domestic Hot Water demand (DHW).

2. CH Pump - operates during a Central Heat demand (CH).

3. Boiler Pump - operates during any demand

Ensure pumps are oriented as per the manufacturers’ instructions. Wiring of these circulators will depend on the

system configuration selected; see Figures 10-3 through 10-6. For further wiring details see Section 12.0.

Circulators responsible for forcing the water flow through the boiler must be sized

according to Table 10-4. Pump recommendations are based on a Primary/Secondary
plumbing configuration (see Figures 10-3 and 10-4) using the listed pipe size in the Boiler-Primary Loop, with
up to 50 equivalent feet of pipe length. The installer is responsible for sizing the boiler circulator(s) and piping
for applications using non Primary/Secondary plumbing; Figure 10-2 provides Head Loss curves for this
purpose.

Failure to ensure the minimum water flow rate through the boiler when the burner is

operating will result in “short-cycling”, reduced performance and operating efficiency,
and may also cause overheating and premature failure which will void the warranty. Failure to follow
instructions may result in fire, property damage, serious injury or death.

41

Model

Temp.

Rise (ºF)

Boiler Flow

Rate (GPM)

Boiler Head

Loss (ft)

Minimum

Pipe Size

Recommended Primary Loop Pump Size

(1)

B&G

Grundfos

Taco

Armstrong

Tx51

35

2.4

7.2

¾”

NRF-22

UPS15-58 (1)

005

Astro 30 (2)

25

3.3

12

¾”

NRF-25 (3)

UPS15-58 (3)

008

Astro 50 (3)

20

4.1

16.6

¾”

NRF-36 (2)

UPS26-99 (2)

0011

E7

Tx81

35

4.2

7.4

¾”

NRF-22

UPS15-58 (2)

008

Astro 30 (3)

25

5.9

13.4

1”

NRF-36 (1)

UPS26-99 (2)

0011

Astro 50 (3)

20

7.4

20.4

1”

NRF-36 (2)

UPS26-99 (3)

0011

E7

Tx101

35

5.2

8.2

1”

NRF-22

UPS15-58 (2)

008

Astro 30 (3)

25

7.3

13.6

1”

NRF-36 (2)

UPS26-99 (2)

0011

E7

20

9.1

19.8

1”

NRF-36 (3)

UPS26-99 (3)

0011

E7

Tx151

35

7.7

11.2

1”

NRF-25 (3)

UPS26-99 (2)

0011

Astro 50 (3)

25

10.8

18.4

1-1/4”

NRF-36 (3)

UPS26-99 (3)

0011

E7

20

13.5

13.1

1-1/4”

PL-36

UPS26-116

2400-20

E8

Notes:

1

Pump sizing based on Primary/Secondary plumbing configuration with specified minimum pipe diameter with up to 50’

equivalent length.

2

Model Tx151C incorporates the circulator responsible for generating flow through the boiler, therefore sizing the

circulator for boiler flow rate is not necessary.

Figure 10-2(a) Tx51 & Tx81 Head Loss Curves

0

5

10

15

20

25

30

2 4 6 8

Flow Rate (US gpm)

Head Loss (ft)

Tx51
Tx81

Tx Series Installation and Operation Instructions │Trinity

Table 10-4 Circulator and Pipe Size Requirements

42

Figure 10-2(b) Tx101 & Tx151 Head Loss Curves

0

5

10

15

20

25

30

2 4 6 8 10 12 14

Flow Rate (US gpm)

Head Loss (ft)

Tx101
Tx151

Trinity │Installation and Operation Instructions Tx Series

Air Removal – The boiler and system plumbing layout must be configured to promote the removal of air from

the water. Air vents and bleeders must be strategically placed throughout the system to aid in purging the air
from the system during commissioning of the boiler. The system must also employ the use of a strategically
located air removal device, such as an air-scoop or micro-bubbler, designed to remove the air from the water as
it flows through the system.

Follow the installation instructions included with the air removal device when placing it

in the system; air removal devices generally work better when placed higher in the
system. Always locate air removal devices in areas of the system that have a guaranteed positive pressure, e.g.,
in close proximity to the water fill and expansion tank.

Trinity Tx boilers are equipped with an automatic air vent to aid in purging of air from

the boiler during the initial fill. This air vent is not intended to be the primary air
removal device in the system.

Expansion Tank – The expansion tank must be sized in accordance with the water volume of the system as well
as the firing rate of the appliance. It is important to locate the expansion tank, and make-up water fill, on the
inlet side of any circulator in the system, as doing so will guarantee the lowest pressure in the system will be at
least equal to the tank and make-up water pressure. See examples in Figures 10-3 through 10-6.

Ensure the expansion tank cannot become isolated from the boiler anytime the system is

operating. Failure to follow these instructions may result in discharge of the Pressure
Relief Valve may result in property damage or personal injury.

The installation of flow checks, motorized valves or other shutoff devices (other than for

the purpose of servicing) are not permitted between the location of the "Closely Spaced
Tees" and the expansion tank; see Figures 10-3 through 10-6.

43

Tx Series Installation and Operation Instructions │Trinity

Indirect Fired Water Heater – When installed as per Figure 10-4, the indirect fired water heater is in series

with the boiler during a demand for DHW. Therefore, its head loss, along with the head loss of the boiler and
associated piping, must be considered when sizing the circulator.

Figures 10-3 through 10-6 are examples of plumbing configurations using either single or multi system
circulators.

Figure 10-3: Single System Circulator Configuration (non-Combi) - Used in applications zoned with “Zone
Valves”. During a demand for Central Heat, the boiler energizes CH Pump and Boiler Pump. The CH Pump

must be sized to provide adequate circulation throughout the heating system. During a Domestic Hot Water
(DHW) demand, the boiler de-energizes the CH Pump and energizes the DHW Pump and Boiler Pump. With
this configuration the Boiler Pump is the only circulator that causes flow through the boiler and it must be sized
in accordance with Table 10-4.

The piping configuration described above requires the Central Heating system and DHW

system to be de-coupled from the “Primary Loop” via closely spaced tees (Figure 10-3).
Figure 10-4: Multiple System Circulator Configuration (non-Combi) - Used in applications with “Zone

Circulators”. This configuration requires the installation of a check valve located at each circulator. During a
Central Heat demand the boiler energizes CH Pump. During a Domestic Hot Water (DHW) demand, the boiler
de-energizes CH Pump and energizes DHW Pump. In this configuration both CH Pump and DHW Pump are
responsible for water flow through the boiler and must be sized in accordance with Table 10-4.

Figure 10-5: Single System Circulator Configuration (Combi) - Used in applications zoned with “Zone
Valves”. During a demand for Central Heat, the boiler energizes CH Pump. The CH Pump must be sized to
provide adequate circulation throughout the heating system. During a Domestic Hot Water (DHW) demand, the
boiler de-energizes the CH Pump. The internal circulator of the Tx151C always provides the boiler water
circulation.

Figure 10-6: Multiple System Circulator Configuration (Combi) - Used in applications with “Zone
Circulators”. This configuration requires the installation of a check valve located at each of the zone circulators.

The internal circulator of the Tx151C always provides the boiler water circulation.

Figures 10-3 through 10-6 illustrate typical piping systems. These piping schematics do

not illustrate all of the required concepts and components required to have a proper
installation. Concepts not shown include: prevention of thermal-siphoning (heat traps), isolation valves, drain
and purge valves, etc. It is the responsibility of the installing contractor and system designer to determine which
system best meets the need of the installation and to consider all aspects of a proper system design. Contractor
modifications to these instructions may be required, based upon existing piping and system design.

44

Figure illustrates the basic
plumbing requirements for
a Tx51-151 (non-Combi) boiler installation with a
single Central Heating circulator. Refer to Figures
10-1(a) and 10-1(b) for boiler fitting identification.

Trinity │Installation and Operation Instructions Tx Series

Figure 10-3 Tx51-151 Primary-Secondary Plumbing (non-Combi)

(Single System Circulator Configuration)

45

Figure illustrates the basic

plumbing requirements for
a Tx151C (Combi) boiler installation with a single
Central Heating circulator. Refer to Figures 10-1(c)
and 10-1(d) for boiler fitting identification.

Tx Series Installation and Operation Instructions │Trinity

Figure 10-4 Tx51-151 Primary-Secondary Plumbing (non-Combi)

(Multiple System Circulator Configuration)

46

Pressure Gauge

Primary Loop

(factory supplied)

Figure illustrates the basic

plumbing requirements for
a Tx151C (Combi) boiler installation with a single
Central Heating circulator. Refer to Figures 10-1(c)
and 10-1(d) for boiler fitting identification.

Trinity │Installation and Operation Instructions Tx Series

Figure 10-5 Tx151C Primary-Secondary Plumbing (Combi)

(Single System Circulator Configuration)

47

Pressure Gauge

Primary Loop

(factory supplied)

Figure illustrates the basic

plumbing requirements for
a Tx151C (Combi) boiler installation with a multiple
central heating circulators. Refer to Figures 10-1(c)
and 10-1(d) for boiler fitting identification.

Tx Series Installation and Operation Instructions │Trinity

Figure 10-6 Tx151C Primary-Secondary Plumbing (Combi)

(Multiple System Circulator Configuration)

48

Trinity │Installation and Operation Instructions Tx Series

11.0 DOMESTIC HOT WATER (DHW) PIPING – Tx151C (COMBI)

The Trinity Tx boiler comes in two versions; non-Combi (Tx51-151) and Combi (Tx151C). Both versions are
designed to provide Central Heating and Domestic Hot Water (DHW) heating. To provide DHW heating, the
non-Combi version must be installed in combination with an Indirect Fired Hot Water Heater, as in Figures 10-3
and 10-4. The Tx151C incorporates a DHW heat exchanger (Brazed Plate) and the controls necessary to heat
DHW without requiring the addition of an Indirect Fired Hot Water Heater.

The Tx151C is designed for installations where there is a limited DHW demand, such as smaller apartments and
condos. In applications where there is a greater DHW demand NTI recommends the Tx51-151 (non-Combi)
installed with an Indirect Fired Hot Water Heater (Figures 10-3 & 10-4), or a Tx151C installed with a DHW
storage tank (Figure 11-2).

Hard Water – To prevent the formation of scale on the inside of the brazed plate heat exchanger and other
components in the domestic hot water system, water with hardness higher than 50 ppm Calcium Carbonate must
be treated with a “Water Softener” prior to entering the appliance. Plugging of the domestic system by scaling or
accumulation of dirt is not the responsibility of NY Thermal Inc., and suitable steps shall be taken to avoid it.

Cleaning – Brazed plate heat exchangers operate with high turbulence flow, even at low flow rates. This high
turbulence keeps small particles in suspension minimizing fouling and scaling. However, in some applications
the fouling tendency can be very high, e.g. when using extremely hard water at high temperatures. In such cases
it is always possible to clean the exchanger by circulating a cleaning liquid. Use a tank with weak acid, 5%
phosphoric acid or, if the exchanger is frequently cleaned, 5% oxalic acid. Pump the cleaning liquid through the
exchanger. For optimum cleaning, the cleaning solution flow rate should be a minimum of 1.5 times the normal
flow rate, preferably in a back-flush mode. After use, do not forget to rinse the heat exchanger carefully with
clean water. A solution of 1-2% sodium hydroxide (NaOH) or sodium bicarbonate (NaHCO3) before the last
rinse ensures that all acid is neutralized. Clean at regular intervals.

DHW Description of Operation

The Tx151C heats domestic hot water on demand, indirectly, using an internal brazed plate heat exchanger. An
internal flow sensor detects potable water flow; when in excess of 0.3gpm the controller operates in DHW mode,
whereby the potable water is heated to the “DHW Setpoint” (Installer Menu setting 2-07). Set “DHW Setpoint”
to the desired hot water temperature; to avoid the risk of scalding a Thermostatic Mixing Valve must be installed,
see Figure 11-1.

Code requirements may require the maximum setting of the Thermostatic Mixing Valve to
be fixed at 120°F or lower, see “Thermostatic Mixing Valve” below and the instructions

included with the valve.

Scald Hazard - Hotter water increases the risk of scald injury. There is a hot water scald

potential if a thermostatic mixing valve is not used or is set too high. Be sure to follow
the adjustment instructions provided with the thermostatic mixing valve. Failure to follow these instructions may
result in serious injury or death.

49

Figure 11-1 Near Boiler DHW Piping (Tx151C)

Tempering Valve

(Check local codes)

Isolation Valve

Y-Strainer

(Factory supplied)

Drain Valve

DHW Inlet (Cold)

DHW Outlet (Hot)

Cold Water Supply

DHW to Fixtures

Tx Series Installation and Operation Instructions │Trinity

Combi DHW Plumbing & Set-up

DHW Inlet & Outlet Connections – The Tx151C has two potable water connections, Inlet & Outlet, which exit
the bottom of the unit, nearest the back. The Inlet fitting is on the right and the Outlet fitting is on the left, see
Figure 11-1.

DHW Filter – Install the factory supplied Y-strainer prior to the inlet fitting, as illustrated in Figure 11-1. The
serviceable Y-strainer has a 100 micron filter and will protect the internals from damage caused by dirt and
debris.

Check Valve – The installation of a check valve in the hot water line is recommend to prevent expansion devises
downstream from back flowing when the water pressure drops during cold water draws. Failure to prevent the
backflow will cause a momentary forward flow of water through the flow sensor when the cold-water draw has
ended and the water pressure increases. This forward flow of water will momentarily activate DHW mode.

Throttling Valve – Use one of the isolation valves, installed hot water line, as a throttle valve to regulate the
maximum hot water flow rate. The Tx151C is limited to a firing rate of 151MBH; therefore excessive flow rates
will result in cooler hot water temperatures.

Drain and Isolation Valves – Install drain and isolation valves on the cold water inlet and hot water outlet lines,
as shown in Figures 11-1 and 11-2, to allow for servicing of the internal brazed plate heat exchanger and other
potable water components. It will be necessary to flush or clean the brazed plate heat exchanger, if it is exposed
to hard water.

Instantaneous DHW (without Storage Tank)

The Tx-Combi will provide domestic hot water continuously when flow is present. This method is the most
efficient means of heating water by allowing the boiler to operate at a lower return water temperature, thus
increasing combustion efficiency, and minimizing standby losses. See Figure 11-1 for installation details.

50

Table 11-1 Tx151C DHW Maximum Flow Rates (USgpm)

Inlet Water Temperature (deg. F)

40

45

50

55

60

65

70

Outlet Water (F)

110

3.9

4.2

4.5

4.9

5.4

6.0

6.7

115

3.6

3.9

4.2

4.5

4.9

5.4

6.0

120

3.4

3.6

3.9

4.2

4.5

4.9

5.4

125

3.2

3.4

3.6

3.9

4.2

4.5

4.9

130

3.0

3.2

3.4

3.6

3.9

4.2

4.5

135

2.8

3.0

3.2

3.4

3.6

3.9

4.2

140

2.7

2.8

3.0

3.2

3.4

3.6

3.9

Trinity │Installation and Operation Instructions Tx Series

DHW Limitations – Since the Tx-Combi produces domestic hot water instantaneously; there are inherent

limitations of the system:
 NO STORAGE – Overall flow through the fixtures must be regulated/limited so not to exceed the ability of

the boiler to heat the water. Exceeding the flow rate indicated in Table 11-1 or 11-2 will result in cooler than
desired hot water.

 COLD START OPERATION – Normally the boiler only fires the burner when there is hot water flow,

therefore you can expect an added delay in the delivery of hot water, due to the time associated with igniting
the burner and heating the water. Also, if the flow at the fixture is momentarily turned off, then turned back
on again, the burner will follow suite. This will cause cold unheated water to pass through the unit, and
advance through the domestic plumbing between the previously heated (hot) water, and the newly heated
(hot) water. This can be mistaken for an inability to adequately heat the water and is often referred to as “Cold

Water Sandwich”, since there is cold water “sandwiched” between hot water. Turning the “Preheat Mode”
ON will improve the delivery of domestic hot water and limit the “Cold Water Sandwich” effect.

Preheat Mode – For improved domestic hot water comfort, the Tx-Combi incorporates a “Preheat Mode” feature
(Installer Menu setting 2-10). When set to ON the boiler control will function to keep the DHW preheated to
limit the wait time associated with a tankless hot water system, and to help avoid the “Cold Water Sandwich”. In
systems where a storage tank is used (See Figure 11-2), Preheat Mode should be disabled, e.g. set to OFF.

Procedure for Setting up Domestic Hot Water – If the Combi is being installed in an application that uses
municipal water, often the pressure is high enough to generate flow rates at the faucets that will exceed the
appliances capacity to heat it. See the following tables to determine the maximum flow rate that can be heated at
given inlet and outlet water temperatures.

To avoid having too much flow at the faucets use an isolation valve to limit the overall flow of domestic hot
water. Follow these instructions to achieve the best delivery of DHW:

 Open throttle/isolation valves fully.
 Turn the dial on the mixing valve to the desired setting (recommend 120˚F max.).
 Create the maximum amount of DHW flow that is likely to occur on a regular basis. (Usually tub faucet,

or choose two other faucets)

 Observe the flow rate indicated on the Tx display (User Menu 1-05), if greater than the applicable flow

rate in Table 11-1 then throttle an isolation valve until the maximum flow rate is achieved.

If the flow rates listed in Table 11-1 are not high enough for the application, install a

storage tank with re-circulating loop as per below and Figure 11-2.

51

Figure 11-2 DHW Piping with Optional Storage Tank (Tx151C)

Y-Strainer (factory
supplied)

Drain Valve

Outlet

Inlet

Isolation Valve

Potable Circulator

(w/ check valve)

Cold Inlet / Drain

Recirculation Inlet

Thermostatic

Mixing Valve

Hot Outlet

Cold Water Supply

DHW to Fixtures

Tx Series Installation and Operation Instructions │Trinity

Tx-Combi w/ DHW Storage Tank

To completely avoid the DHW limitations inherent with on demand hot water heating, install a DHW storage tank
as per Figure 11-2. When the tank temperature is insufficient, a Thermostat located within the storage tank
completes a 120VAC circuit to operate a Potable (bronze or Stainless Steel) Circulator pump. The pump
circulates water from the bottom of the storage tank (typical location of a drain fitting) to the DHW inlet fitting of
the Tx-Combi. The internal DHW flow sensor senses the water flow and triggers a DHW demand; heated water
flows from the Tx-Combi and enters the Recirculation Inlet fitting of the storage tank.

When using a Storage Tank, set Preheat Mode (Installer Menu setting 2-10) to OFF to

prevent the boiler from redundantly maintaining DHW temperature.

52

Control Panel

swings out

Field Wiring

Terminals

Trinity │Installation and Operation Instructions Tx Series

12.0 FIELD WIRING

All wiring must be in accordance with the Canadian Electrical code, CSA C22.2 and any applicable local codes.
Ensure that the wiring complies with this manual. The boiler must be electrically grounded in accordance with
the National Electrical Code ANSI/NFPA 70, local codes, and/or the Canadian Electrical Code CSA C22.1.

wiring connections are being made. Failure to follow these instructions may result in component failure, serious
injury or death.

Wiring Connections

Electrical rating for the Trinity Tx is 120V / 1 Phase / 60 Hz / 12A. All wiring connections to the Trinity Tx are
made at the junction box, located behind the control panel at the bottom of the boiler cabinet, see Figure 12-1.
Field wiring enters the cabinet through holes located on the bottom (underside) of the boiler cabinet; use suitable
strain-relief grommets to protect the wires. Field wiring connections are to be installed in accordance with
instructions provided in Figure 12-2 and Table 12-1.

Fuse (120VAC) - The Trinity Tx is equipped with a 3.15 Amp fuse located at “F1” on the boiler controller at the
top left; the fuse protects all 120VAC circuits within the boiler, as well as any circulators connected to it. A
spare fuse is located directly below the operating fuse in an open holder.

Failure to follow instructions may result in component failure, serious injury or death.

Amps. Failure to follow instructions may result in component failure, serious injury or death.

Avoid Shocks - To Avoid Electrical Shock, turn off electrical power to the boiler prior to

opening any electrical box within the unit. Ensure the power remains off while any

Field Wiring - Wire grommets must be used to secure wiring and prevent chafing when
passing wiring through the cabinet wall. Failure to follow instructions may damage unit.

Wire Protection - When passing any wiring through the cabinet of the boiler, the

installer must use wire grommets suitable for securing the wiring and preventing chafing.

Power Supply - The Trinity Tx is designed to be powered using a single phase 120VAC

power supply that is fused (or protected via a circuit breaker) to allow a maximum of 15

Figure 12-1 Wiring Terminal Access

53

Connection

Location

Description

ARGUS LINK –

1

Argus Link Communication – used to cascade up to 16 boilers, also for connection
to USB interface for PC-connection and BMS Modbus/Expansion Interface Module.

ARGUS LINK +

2

SENSOR

COMMON

3

Sensor Common – Common port for field inputs SYSTEM, OUTDOOR and DHW.

SYSTEM

4

System Temperature Sensor (Optional) – Wire to terminals 3 and 4 of the main
boiler in a cascade. Sensor would be installed on the system supply pipe feeding the
Central Heating system to allow accurate control of system temperature. Sensor is
available from NTI, P/N: 84010.

OUTDOOR

5

Outdoor Temperature Sensor – A wall mountable OD Sensor is included with

each boiler; connect to terminals 3 and 5. In a cascade, the OD Sensor only needs to
be connected to the main boiler. The use of the OD Sensor is required to allow the
boiler control to automatically infer the heat load of a central heating system.

DHW

6

Tank Thermostat / Sensor (Not Applicable for Combi model Tx151C) – Connect
the contacts of a DHW Tank Thermostat, or leads of an approved DHW Tank Sensor
(NTI P/N: 84632), to terminals 3 and 6. When using a Thermostat, set DHW mode
= 2 (menu setting 2-08). When using a Sensor, set DHW mode = 1. See Section

17.0 for more details.

THERMOSTAT

7

24VAC Room Thermostat Input – Connect central heat demand switch (room
thermostats or zone control end switch) to terminals 7 and 8. Switch must be an
isolated end switch.

8

DHW PUMP

9

120VAC output to the DHW circulator; powered during a demand for DHW. Total
load of DHW PUMP and BOILER PUMP must not exceed 2.6Amps. Not applicable
for Combi model Tx151C.

CH PUMP

10

120VAC output to the Central Heating circulator; powered during a demand for
Central Heat. Total load of CH PUMP and BOILER PUMP must not exceed

2.6Amps.

BOILER PUMP

11

120VAC output to the main boiler circulator; powered during all demands. Total
load of BOILER PUMP and CH PUMP (or DHW PUMP) must not exceed 2.6Amps.
Not applicable for Combi model Tx151C – pump is factory wired.

L2 NEUTRAL

12

Location for connecting neutral of the power supply and all circulators.

13

L1 120VAC

14

Location for connecting line voltage of the power supply. Note; most installation
codes require the installation of a service switch to break line voltage to the
appliance.

Ground

Green Wire

Location for connecting earth ground and for grounding all circulators.

Safety Circuit

Purple Wire

120VAC Safety Limit Circuit – Purple wire located in junction box; line can be cut
and connected to optional external limits, i.e. LWCO.

Tx Series Installation and Operation Instructions │Trinity

Labeling - Label all wires prior to disconnecting them when servicing controls. Wiring

errors can cause improper and dangerous operation. Failure to follow instructions may

result in property damage or personal injury.

Continuity - Before connecting the line voltage wiring, perform a continuity check
between all wires and ground to make sure that there are no electrical leaks that could

blow a fuse or damage electrical components. Also check the polarity of the line and neutral wires. Line must
measure 120VAC to ground; neutral must measure zero. Failure to follow instructions may damage the unit.

Max Load – The total load rating of circulators powered by outputs BOILER PUMP and
CH PUMP, or BOILER PUMP and DHW PUMP can not exceed 2.6 Amps.

54

Trinity │Installation and Operation Instructions Tx Series

Figure 12-2 Field Wiring

55

Tx Series Installation and Operation Instructions │Trinity

13.0 CASCADE INSTRUCTIONS

The Tx controller has the internal capacity to cascade (lead-lag / stage) up to 16 Tx boilers, without the use of an
external controller. Use the instructions detailed in this section to set-up and install the Tx cascade system.

Figure 13-1 Cascade Plumbing Schematic

Communication Wiring – for each boiler in the cascade, wire in parallel electrical connections Argus Link (-)

and Argus Link (+), terminals 1 and 2 (see Figure 12-2).

Establish Managing Boiler – choose one boiler to be the Managing Boiler, this boiler will receive all control
wiring and will be used for setting control parameters (see steps below). All non-Managing Boilers must have the
“S4” switch (located on the top right side of the control) switched OFF. *

* Note: the “S4” switch is factory set to ON. The switch is in the off position when it is closest to the “S4”

marking. The “S4” switch must remain in the ON position on the Managing Boiler.

Plumbing – install the boilers in parallel in a primary/secondary plumbing configuration as illustrated in Figure
13-1. Size common piping as per Table 13-1.

56

# of Units

Tx51

Tx81

Tx101

Tx151

Pipe Size

Pipe Size

Pipe Size

Pipe Size

2

1”

1-1/4”

1-1/4”

1-1/2”

3

1-1/4”

1-1/2”

1-1/2”

2” 4 1-1/4”

1-1/2”

2”

2”

5

1-1/2”

2”

2”

2-1/2”

6

1-1/2”

2”

2”

2-1/2”

7

1-1/2”

2”

2-1/2”

2-1/2”

8

2”

2”

2-1/2”

2-1/2”

9

2”

2-1/2”

2-1/2”

3”

10

2”

2-1/2”

2-1/2”

3”

11

2”

2-1/2”

2-1/2”

3”

12

2”

2-1/2”

2-1/2”

3”

13

2”

2-1/2”

3”

3”

14

2”

2-1/2”

3”

4”

15

2”

2-1/2”

3”

4”

16

2-1/2”

3”

3”

4”

Note: Minimum pipe size based on assumed temperature rise of 25ºF at maximum firing rate.

Trinity │Installation and Operation Instructions Tx Series

System Sensor – install a system sensor (NTI P/N: 84010) on the outlet (supply) pipe feeding the heating system,

see Figure 13-1. Wire the system sensor to terminals 3 and 4 of the Managing Boiler (left boiler in illustration).

IMPORTANT: the use of the system sensor is mandatory for proper operation of the boiler cascade system.

Outdoor Sensor – when using an outdoor sensor it must be connected to terminals 3 and 5 of the Managing

boiler (left boiler in illustration); outdoor sensors connected to non-Managing boilers will be ignored.

Boiler Pump – each boiler in the cascade must have its own circulator (see Figure 13-1) which is operated by
each respective boiler, via the BOILER PUMP output (terminal 11). The Boiler Pump must be sized according to
Table 10-4.

CH Pump – the Managing Boiler can control the Central Heating Pump via its CH PUMP output (terminal 10).
IMPORTANT: due to the limited switching capacity of the CH PUMP output, it may be necessary to use an

isolation relay to activate the CH Pump, see Table 11-1.

DHW Pump – the Managing Boiler can control the DHW Pump via its DHW PUMP output (terminal 9).
IMPORTANT: due to the limited switching capacity of the DHW PUMP output, it may be necessary to use an

isolation relay to activate the DHW Pump, see Table 11-1.

Central Heat Demand Switch (Room Thermostat) – connect to terminals 7 and 8 (T, T) of the Managing
Boiler. Switch must be an isolated end switch (dry contact). Central Heat settings are programed from the
Managing Boiler only, i.e. Installer menu settings 2-01, 2-02, 2-03, 2-04, 2-05 and 2-06.

Tank Thermostat / Sensor – connect to terminals 3 and 6 of the Managing Boiler. DHW settings are programed
from the Managing Boiler only, i.e. Installer menu settings 2-07, 2-08 and 2-09. Set DHW Mode (Installer menu
setting 2-08) according to device used; Thermostat = 2, Sensor = 1.

Boiler Address – assign a unique boiler address for each boiler in the cascade via Installer menu setting 2-20.
Managing boiler must be set = 1; other boilers must be set from 2 to 16.

Rotation Interval – establishes the time, in days, between advancements of the staging sequence of boilers in the
cascade; set via Installer menu setting 2-22 of the Managing Boiler.

Emergency Setpoint – establishes an emergency (back-up) boiler operating setpoint in the event communication
is lost between boilers, or if the system sensor is not connected. Set via Installer menu setting 2-21 of each boiler
in the cascade.

Table 13-1 Minimum Pipe Sizes for Multiple Boiler Applications

57

Figure 14-1 Tx Connection Diagram

Tx Series Installation and Operation Instructions │Trinity

14.0 WIRING SCHEMATICS

58

Figure 14-2 Tx Ladder-Logic Diagram

Trinity │Installation and Operation Instructions Tx Series

59

Tx Series Installation and Operation Instructions │Trinity

15.0 INSTALLATION CHECKLIST
Installation

 1. If operating on Propane Gas, convert boiler using appropriate conversion orifice. See Table 7-1.
 2. Locate the boiler in accordance with Section 3.0 of this manual.
 3. Install the Vent/Air-inlet piping in accordance with Sections 4.0 and 5.0 of this manual. Ensure all

joints are secured and cemented properly. Both the Vent and Air-inlet pipes must terminate outdoors.
Perform the Mandatory Pre-commissioning Procedure for Plastic Venting in Section 4.0.

 4. Connect the condensate trap and drain in accordance with Section 6.0 of this manual.
 5. Connect the gas supply in accordance with Section 7.0 of this manual.
 6. Install the plumbing in accordance with this manual. Flush/cleanse the internals of the heating system.

Treat system water with Fernox F1 Protector when needed.

 7. Connect field wiring in accordance with Section 12.0 of this manual.
 8. Advise home/building owner of their responsibilities with respect to maintaining the boiler.

The building owner is responsible for keeping the Vent/Air-inlet termination free of snow,
ice, or other potential blockages and for scheduling boiler routine maintenance as

described in the next section. Failure to properly maintain the boiler may result in serious injury or death.

Start-up

Plastic Venting in Section 4.0. Failure to follow these instructions can result in explosion, serious injury or death.

 1. Turn gas shut-off valve to the ON position.
 2. Turn Power on to the boiler.
 3. Set Controller to the desired settings.
 4. Turn thermostat up, Ignition will occur.

Operational Checklist

 1. System is free of gas leaks.
 2. System is free of water leaks.
 3. Water pressure is maintained above 15 PSI.
 4. All air is purged from the heating system piping.
 5. Ensure proper water flow rate; unit must not kettle, bang, hiss or flash the water to steam.
 6. Ensure gas line pressure is in accordance with Section 9.0.
 7. System is free of combustion leaks.
 8. Unit must operate smoothly.
 9. Ensure the flue gas combustion readings are within the tolerances listed in Table 9-1.
 10. Each ignition must be smooth.
 11. Verify that all condensate lines are clean and drain freely.

Before Leaving

 1. Remove line pressure gauge from gas valve, tighten bleed screw, test screw for leaks. See Section 9.0.
 2. Install plug into the flue gas test port and test for leaks, see Section 9.0.
 3. Allow the boiler to complete at least one heating cycle, or to operate for at least 15 minutes.
 4. Always verify proper operation after servicing.

Instructions to Installing Contractor

 1. Ensure that the customer receives the Warranty Documentation included with the installation manual.
 2. Leave the manual with the customer so they know when to call for annual maintenance and inspection.

matches the need of the application may result in fire, property damage, or death.

Allow primers/cements to cure for 8 hours prior to Start-up. If curing time is less than 8
hours, first perform Steps 2 through 6 of Mandatory Pre-commissioning Procedure for

This boiler must have water flowing through it whenever the burner is firing. Failure to
comply may damage the unit, void the warranty, and cause serious injury or death.

Allowing the boiler to operate with a dirty combustion chamber will adversely affect its
operation and void the warranty. Failure to clean the heat exchanger on a frequency that

60

Trinity │Installation and Operation Instructions Tx Series

16.0 ANNUAL MAINTENANCE AND INSPECTION

This unit must be inspected at the beginning of every heating season by a Qualified Technician.

Annual Inspection Checklist

 1. Lighting is smooth and consistent, and the combustion fan is noise & vibration free.
 2. The condensate drain freely flows, and is cleaned of sediment.
 3. Relief Valve and air vents are not weeping.
 4. Low water cut off is tested (if applicable)
 5. Examine all venting for evidence of leaks. Ensure vent screens are cleaned and clear of debris.
 6. Check the burner plate for signs of leaking.
 7. The combustion chamber must be inspected and if necessary cleaned.
 8. Keep boiler area clear/free from combustible materials, gasoline, and other flammable vapors and liquids.
 9. Ensure there is nothing obstructing the flow of combustion and ventilation air.
 10. Listen for water flow noises indicating a drop in boiler water flow rate.

Important - The hydronic system may need to be flushed to eliminate hard water scale
(Use Fernox DS-40 Descaler, NTI PN: 83450).

 11. Verify proper operation after servicing.

Combustion Chamber Cleaning Procedure

NTI recommends having the combustion chamber cleaned after the first year of operation, with subsequent
cleanings scheduled based on the condition of the combustion chamber at the time of the first cleaning. Units
operating with LP Gas or in an industrial environment may require more frequent cleanings.

chamber. Take all necessary precautions and use recommended personal protective equipment as required.

Cleaning Checklist

 1. Remove the demand for heat, allow the post-purge cycle to finish, turn gas and power supply off.
 2. Working inside the cabinet, swing the control panel out of the way, disconnect the cabling to the

combustion blower, gas valve, spark igniter and flame sensor, then remove the air-inlet and gas supply
piping.

 3. Once the combustion chamber has cooled, remove the four (4) nuts securing the burner assembly to the

heat exchanger, then remove the assembly (burner door, blower and gas valve) – be careful not to damage
the insulation disc located behind the burner door. Replace insulation if it is damaged.

 4. Inspect the condition of the insulation at the back of the chamber; cover it to protect it from becoming wet

during the cleaning process. If the insulation is damaged, remove it and install new insulation once the
heat exchanger cleaning is complete.

 5. Use a vacuum with a high efficiency filter to remove any loose debris or dust.
 6. Remove the condensate trap from the bottom of the boiler and place a drain under the boiler condensate

drain.

 7. Wet the inside of the combustion chamber with warm water (do not use any chemicals). Use a garden hose

with a trigger nozzle to direct pressurized water between the heat exchanger tubes; the water will exit via
the condensate drain on the bottom. Continue process until the gaps between the tubes are clear and the
water runs clean. Use dry rags or plastic to protect electrical components from being damaged by dripping
or spraying water.

 8. Disassemble the condensate trap and thoroughly clean it; then reassemble and securely connect it to the

boiler condensate drain, see Section 6.0.

 9. Reassemble the boiler in the reverse order of disassembly.
 10. Perform the Start-up and Operational Checklist detailed in the previous section.

Wiring Labels - Label all wires prior to disconnection when servicing controls. Wiring

errors can cause improper and dangerous operation.

Cleansers and Potable Water - Boiler system cleansers and corrosion inhibitors must not

be used to flush contaminants from water heaters or potable water systems.

Crystalline Silica - Read carefully the warnings and handling instructions pertaining to

Refractory Ceramic Fibers before commencing any service work in the combustion

Replace any gaskets or insulation discs that show any signs of damage and do not re-use.

Failure to follow these instructions may result in fire, property damage or death.

61

Reduce the Risk of Exposure

Precautions and Recommended Personal Protective Equipment

Avoid contact with skin and eyes

 Wear long-sleeved clothing, gloves, and safety goggles or glasses.

Avoid breathing in silica dust

 Wear a respirator with an N95-rated filter efficiency or better. 1
 Use water to reduce airborne dust levels when cleaning the combustion chamber.
 Do not dry sweep silica dust. Pre-wet or use a vacuum with a high efficiency filter.

Avoid transferring contamination

 When installing or removing RFCs, place the material in a sealable plastic bag.
 Remove contaminated clothing after use. Store in sealable container until cleaned.
 Wash contaminated clothing separately from other laundry.

First Aid Measures

If irritation persists after implementing first aid measures consult a physician.

 Skin - Wash with soap and water.
 Eyes - Do not rub eyes; flush with water immediately.
 Inhalation – Breathe in fresh air; drink water, sneeze or cough to clear irritated

passage ways.

Notes:

1

Respirator recommendations based on CCOHS and OSHA requirements at the time this document was written. Consult

your local regulatory authority regarding current requirements for respirators, personal protective equipment, handling,
and disposal of RCFs.

For more information on Refractory Ceramic Fibers, the risks, recommended handling procedures and
acceptable disposal practices contact the organization(s) listed below:

Canada (CCOHS): Telephone directory listing
under Government Blue Pages Canada—Health and
Safety—Canadian Centre for Occupational Health
and Safety; or website http://www.ccohs.ca.

United States (OSHA): Telephone directory listing
under United States Government—Department of
Labor—Occupational Safety and Health
Administration; or website http://www.osha.gov.

Tx Series Installation and Operation Instructions │Trinity

Refractory Ceramic Fibers (RFC)

chamber. The insulating material on the inside of the burner plate contains Refractory Ceramic Fibers and
should not be handled without personal protective equipment.

(cristobalite), a respirable silica dust. Repeated airborne exposure to crystalline silica dust may result in chronic
lung infections, acute respiratory illness, or death. Crystalline silica is listed as a (potential) occupational
carcinogen by the following regulatory organizations: International Agency for Research on Cancer (IARC),
Canadian Centre for Occupational Health and Safety (CCOHS), Occupational Safety and Health Administration
(OSHA), and National Institute for Occupational Safety and Health (NIOSH). Failure to comply with handling
instructions in Table 16-1 may result in serious injury or death.

maintenance can cause property damage, serious injury (exposure to hazardous materials) or death. Refer to
Table 16-1 for handling instruction and recommended personal protective equipment. Installation and service
must be performed by a qualified installer, service agency or the gas supplier (who must read and follow the
supplied instructions before installing, servicing, or removing this boiler. This boiler contains materials that have
been identified as carcinogenic, or possibly carcinogenic, to humans).

Table 16-1 Handling Instructions for Refractory Ceramic Fibers (RCF)

Personal Protective Equipment Recommended - Read the following warnings and

handling instructions carefully before commencing any service work in the combustion

Potential Carcinogen - Use of Refractory Ceramic Fibers in high temperature
applications (above 1000oC) can result in the formation of Crystalline Silica

Crystalline Silica - Certain components confined in the combustion chamber may
contain this potential carcinogen. Improper installation, adjustment, alteration, service or

62

Figure 17-1 de-Air Sequence

dAir – indicates the
boiler is performing
the de-Air sequence.

Temperature units

Boiler outlet
temperature

Ok button – press and

hold to skip the de-Air
sequence.

Trinity │Installation and Operation Instructions Tx Series

17.0 DISPLAY MENU GUIDE
Initial Power-up

Immediately following power-up of the boiler, the display reads, “conn”, indicating it is connecting to the
controller; this is followed by a momentary reading of the display software version, e.g. init 5250. After which
the controller performs a de-air sequence that is designed to purge air from the boiler water. The de-air sequence
cycles the circulators off and on, for a period of 7 minutes, in an attempt to free air pockets that may exists in the
heat exchanger and boiler piping.

The de-air sequence is initiated following each power-up of the boiler; if air has already
been adequately purged from the system the de-air sequence can be stopped by holding

the OK button until “dAir” is no longer displayed on the screen, see Figure 17-1.

may lead to property damage and personal injury.

The de-air sequence is designed to remove air from the system; failure to adequately
remove air from the system can damage the heat exchanger and void the warranty, and

Main Screen

Following power-up of the boiler (after the de-air sequence), or after 60 seconds of inactivity (no buttons
pressed), the boiler defaults to the Main Screen, see Figure 17-2. Under normal operating conditions the Main
Screen displays the boiler outlet temperature and water pressure, as well as an indication of the current heat
demand (CH or DHW), burner status and outdoor reset function. See Figure 17-2 for more details.

User Menu access – from the Main Screen, access to the User Menu is accomplished simply by pressing the UP
or DOWN button on the console; see User Menu section below for more details.

Installer Menu access – from the Main Screen or User Menu, access to the Installer Menu is accomplished by
pressing and holding the MENU and OK buttons simultaneously; see Installer Menu section below for more
details.

Return to Main Screen – from the User Menu, return to the Main Screen by pressing the OK button. From the
Installer Menu, return to the Main Screen by pressing and holding the RESET button.

63

Figure 17-2 Control Console – Main Screen

Figure 17-3 User Menu Navigation

Water pressure

Water pressure units

Radiator – flashes
during CH demands

Faucet – flashes
during DHW demands

Menu button

Reset button – press

and hold to clear
lockouts or exit Installer
Menu

Power button

Temperature units

Boiler outlet
temperature

OD reset indicator –

illuminates when OD
sensor is enabled

Down button

Up button

No flame – displayed

during lockout or error

Flame – displayed
when flame is on

Wrench – displayed
when installer settings
are accessed

Ok button – select to
exit User Menu

Item ID # - 14
parameters can be
viewed from the User
Menu (1-01 to 1-14),
see Table 17-1 for
description of each

Units (if applicable)

Value of displayed
parameter

Down button – press

to scroll down through
the menu parameters

Up button – press to
scroll up through the
menu parameters

Ok button – press to
return to Main Screen

Tx Series Installation and Operation Instructions │Trinity

User Menu

The User Menu allows for easy viewing of the current boiler operating conditions, including pump status, sensor
inputs, common set points, and boiler target temperature. Access the User Menu from the Main Screen by
pressing the UP or DOWN button on the display console. Exit the User Menu by pressing the OK button.

The User Menu only permits the user to view boiler information; editing of settings must
be done from the Installer Menu. Access the Installer Menu by pressing and holding the

MENU and OK buttons simultaneously; see Installer Menu section for more details.

64

Menu Item

Description

1-01

Current target temperature – displays the current target temperature of the boiler outlet sensor for the
active demand (DHW or Central Heating). For central heating with outdoor reset, the calculated central
heating target temperature will be displayed. NOTICE: model Tx151C will display “---“ during DHW
demands.

1-02

CH setpoint (at OD = 0⁰F) – displays the maximum central heat setpoint, set via Installer Menu setting 2-

01. Setting establishes the boiler operating temperature during central heat demands when the outdoor
temperature is 0⁰F or less.

1-03

DHW temperature – displays the temperature reading from; (i) the Tank sensor (NTI p/n: 84632) located
in an indirect water heater or (ii) the DHW sensor inside the Tx151C Combi boiler (NTI p/n: 84907).
When no sensor is used, “OPEn” indicates an open circuit, and “CLOS” indicates a closed circuit – i.e.
contact closure from an indirect thermostat.

1-04

DHW setpoint – displays the DHW setpoint, set via Installer Menu setting 2-07.

1-05

DHW flow rate (gpm) – displays the DHW flow rate sensed at the Tx151C Combi DHW sensor.
NOTICE: when the sensor is disconnected, 0.49 is displayed.

1-06

Fan speed actual (rpm) – displays speed at which the combustion blower is operating.

1-07

Flame signal (µA) – displays the flame strength signal sensed from the ionization electrode, NTI p/n:
84740; minimum signal to sustain normal burner operation is 3µA. Burner operation is completely
prohibited when the signal drops below 1.5µA.

1-08

Outdoor sensor temperature – displays reading from outdoor temperature sensor, NTI p/n: 83604.
NOTICE: when sensor is open (not connected) display indicates -40⁰F/C; when sensor is shorted display

indicates 176⁰F/80⁰C and boiler will not fire on CH Modes 1 or 2.

1-09

Return sensor temperature – displays reading from boiler inlet temperature sensor, NTI p/n: 84745.

1-10

Flue sensor temperature – displays reading from boiler flue temperature sensor, NTI p/n: 84780. Burner
operation is inhibited when the flue temperature reading is in excess of 220⁰F. NOTICE: an open circuit
is displayed as 50⁰F/10⁰C and a blocking error “Err 78” occurs; a short circuit is displayed as 278⁰F/137⁰C
and a blocking error “Err 86” occurs.

1-11

Boiler pump – indicates the status (On/Off) of the Boiler Pump output. Note: the Boiler Pump output is on
during all demands.

1-12

Central heat pump – indicates the status (On/Off) of the CH Pump output. Note: the CH Pump output is
on during central heat demands; the CH Pump will turn off during priority DHW demands.

1-13

DHW pump – indicates the status (On/Off) of the DHW Pump output. Note: the DHW Pump output is on
during priority DHW demands.

1-14

System sensor temperature – for use only in cascade systems, displays reading from a system temperature
sensor, NTI p/n: 84010. When used, the system sensor is only wired to the managing boiler, i.e. boiler with
S4 switch set to on, and boiler address (Installer Menu setting 2-20) set to 1. NOTICE: an open circuit is
displayed as “OPEn”; a short circuit is displayed as “CLOS”.

Notes:

1

Enter User Menu by pressing the UP or DOWN button; to scroll through menu options, continue pressing the UP or

DOWN button.

2

Exit User Menu by pressing the OK button.

3

User Menu is for viewing only; to adjust settings refer to the Installer Menu.

Trinity │Installation and Operation Instructions Tx Series

Table 17-1 User Menu

65

Figure 17-4 Installer Menu Navigation

Setting

Description

Factory

Setting

2-01

CH setpoint (at OD = 0⁰F) – establishes the boiler operating temperature during central heat
demands when the outdoor temperature is 0⁰F or less. Set to the maximum desired boiler temperature
for the application, e.g. 100-120⁰F for infloor; 140-160⁰F for cast-iron; 160-190⁰F for baseboard.
Range = 80 to 190⁰F

140⁰F

2-02

CH setpoint differential – establishes how much the boiler outlet temperature must exceed the CH
setpoint before the burner is turned off. Also establishes how much the boiler outlet temperature must
drop below the CH setpoint before the burner is turned on. Range = 3 to 36⁰F

9⁰F

Item ID # - 31
parameters can be
viewed and/or adjusted
from the Installer Menu
(2-01 to 2-32), see
Table 17-2 for
description of each.

Units (if applicable)

Value of displayed
parameter

Down button – press

to scroll down through
the menu parameters,
or to decrease selected
setting.

UP button – press to
scroll up through the
menu parameters, or to
increase selected
setting.

Installer Menu
Access – press and

hold MENU and OK
buttons to enter
Installer Menu.

OK button – press to
select parameter for
adjustment. Press
again to save new
setting.

Installer Menu Exit –

press and hold the
RESET button to exit
the Installer Menu.

Tx Series Installation and Operation Instructions │Trinity

Installer Menu

The Installer Menu allows access to all settings for adjustment, as well as viewing of statistical data for
troubleshooting. Access the Installer Menu from any screen by pressing the MENU and OK buttons
simultaneously until “2-01” is displayed on the top left of the screen. Exit the Installer Menu by pressing and
holding the RESET button.

Installer Menu settings shall only to be adjusted by a qualified installer or service

technician that understands the repercussions of incorrect control settings. Improper
control settings may negatively affect the operation of the boiler and/or the heating system; resulting in property
damage, serious injury or even death.

Adjusting settings – once the Installer Menu is accessed; adjust settings using the following procedure:

1. Use the UP or DOWN button to scroll through the menu until the desired setting number is displayed in the

top-left of the screen (i.e. 2-01).

2. Press the OK button to access the setting; at this time the setting will flash (Note: if the value does not flash

after pressing the OK button, then the parameter is not adjustable – refer to Table 17-2).

3. With the value flashing, use the UP or DOWN button to increase or decrease the setting. Once the desired

value is displayed, press the OK button to enter/save the new value. At this point the value will stop flashing.

4. Repeat for the next setting. Once complete, return to the Main Screen by holding the RESET button.

Table 17-2 Installer Menu

66

Setting

Description

Factory

Setting

2-03

CH mode – determines the operational mode for central heating:

 0 – no outdoor sensor is needed; central heat demand is generated by a thermostat call to

boiler terminals 7 and 8. Boiler operates to setting 2-01; there is no outdoor reset.

 1 – outdoor sensor is needed; central heat demand is generated by a thermostat call to boiler

terminals 7 and 8. Boiler operates in-between settings 2-01 and 2-05 depending on OD temp.

 2 – outdoor sensor is needed; central heat demand is generated when the OD temp is below

the Warm weather shutdown setting (2-04). Boiler operates in-between settings 2-01 and 2­05 depending on OD temp.

 3 – no outdoor sensor is needed; central heat demand is always present, boiler operates to

setting 2-01.

 4 – setpoint from external analog input (0-10VDC); 2 volts for minimum CH setpoint, 10

volts for maximum CH setpoint. Use of an addition interface board through Argus Link is
required.

 5 – modulation from external analog input (0-10VDC); 2 volts for minimum modulation, 10

volts for maximum modulation. Use of an addition interface board through Argus Link is
required.

1

2-04

Warm weather shutdown – inhibits central heat operation when the outdoor temperature reading goes
above this setting. Range = 35 to 100⁰F

100⁰F

2-05

CH setpoint (at OD = 70⁰F) – establishes the boiler operating temperature during central heat
demands when the outdoor temperature is 70⁰F or greater. Set to the minimum desired boiler
temperature for the application, e.g. 70-90⁰F for infloor; 100-120⁰F for cast-iron; 110-140⁰F for
baseboard. Range = 60 to 140⁰F

95⁰F

2-06

Temperature boost – determines the increase in boiler target temperature for every 15 minutes of
continuous central heat demand. Only applicable when an outdoor sensor is used (i.e. CH modes 1 &

2). Target temperature will not exceed CH setpoint setting 2-01. Range = 0 to 36⁰F

0⁰F

2-07

DHW setpoint – establishes: a) tank temperature setting for DHW mode 1 [e.g. 130-140⁰F], b) boiler
outlet setpoint for DHW mode 2 [e.g. 170-190⁰F] or c) DHW temperature for Tx151C combi [e.g.
120-140⁰F]. Range = 104-190⁰F

136⁰F

2-08

DHW mode – determines the operational mode for DHW; for non-combi models Tx51-151 choose
between options 0, 1 and 2; for combi model Tx151C choose between options 0 and 5:

 0 – off; boiler will not attempt to heat DHW in any way.
 1 – tank sensor, NTI p/n: 84632, is installed in the indirect water heater and wired to boiler

terminals 3 and 6. Tank temperature is adjusted via setting 2-07.

 2 – tank thermostat is installed in the indirect water heater and wired to boiler terminals 3 and

6. Setting 2-07 determines boiler outlet temperature during DHW demands. (Default setting
for Tx51-151)

 3 & 4 – settings are not applicable.
 5 – DHW mode setting for combi model Tx151C. Setting 2-07 determines DHW outlet

temperature.

2 or 5

2-09

DHW priority timer – a timer that accumulates during a simultaneous DHW and CH demand. Each
time the timer exceeds the “DHW priority timer” setting, the priority switches from one demand to the

other (i.e. DHW to CH). Note: DHW is assigned priority first. Range = 1-240 minutes

60 min

2-10

Preheat mode – when set to ON, the boiler preheats the DHW inside the brazed plate heat exchanger
of a combi model Tx151C, to reduce the time required for hot water to reach the fixture. Preheat helps
limit the effect of “cold water sandwich” (not applicable for non-combi models Tx51-151). When set
to OFF, the boiler does not preheat the DHW. Range = ON/OFF

OFF

2-11

Appliance selection (type) – indicates what boiler model the controller is configured to operate with:

 1 = Tx51 operating with Natural Gas.
 2 = Tx81
 3 = Tx101
 4 = Tx151
 5 = Tx151C
 6 = Tx51 operating with Propane (LP)

(See Section 17.0 for instruction on changing the appliance selection (type)).

1 - 5

Trinity │Installation and Operation Instructions Tx Series

67

Setting

Description

Factory

Setting

2-12

Minimum firing rate – allows the installer to increase the minimum modulation/firing rate of the
boiler; this may be necessary for troubleshooting. Range = 20-44%

20%

2-13

Maximum firing rate CH – allows the installer to decrease the maximum modulation/firing rate of
the boiler when operating on a central heat demand; this may be necessary for troubleshooting or de­rating the boiler for operation with glycol. Range = 60-100%

100%

2-15

Firing rate test – allows the installer to force maximum or minimum modulation rates for the purpose
of troubleshooting and burner setup (i.e. combustion analysis):

 0 = Automatic; burner modulation is controlled by the controller.
 1 = Minimum; burner operates at the minimum modulation rate.
 2 = Ignition; burner operates at the ignition/light-off modulation rate.
 3 = Maximum; burner operates at the maximum modulation rate.

Note: control will end test (return setting to 0) if the boiler outlet temperature exceeds 176⁰F. Return
setting to 0 when testing is complete.

0

2-16

Service reminder status – feature not available with first generation Tx boilers.

OFF

2-17

Boiler pump postpurge – length of time the Boiler Pump output remains powered once all demands
end. Range = 10-90seconds

30 sec

2-18

CH pump postpurge – length of time the CH Pump output remains powered at the end of a central
heat demand. Range = 0-90seconds

30 sec

2-19

DHW pump postpurge – length of time the DHW Pump output remains powered at the end of a
DHW demand. Range = 0-255seconds

10 sec

2-20

Cascade boiler address – assign a unique boiler address for each boiler in a cascade; managing boiler
address must be set to 1. Managing boiler must have S4 switch set to ON; all others must be set to
OFF. Central heat and DHW demands and setpoints are received and set at the managing boiler only.
A boiler that is not part of a cascade must have the boiler address set to 0.
Range = 0-16

0

2-21

Emergency setpoint – used only for a cascade system, assigns a permanent boiler operating
temperature that is used if communication between boilers is lost, or if the system temperature sensor
becomes disconnected. Range = 104-190⁰F

113⁰F

2-22

Rotation interval – establishes the time between the rotation of start and stop sequences of boilers in
a cascade. Range = 0-30days (0=disable)

5 days
2-23

DHW boiler address – feature not available with first generation Tx boilers.

NA

2-24

System pump postpurge – feature not available with first generation Tx boilers.

NA

2-25

Flame failures – accumulation of the number of flame outages that occurred during run.

NA

2-26

Ignition attempts success – accumulation of the number of successful ignitions.

NA

2-27

Ignition attempts failed – accumulation of the number of failed ignition attempts.

NA

2-28

Run time CH – accumulation of the number of hours that the burner has been firing for the purpose
of central heating.

NA

2-29

Run time DHW – accumulation of the number of hours that the burner has been firing for the purpose
of DHW.

NA

2-30

Post purge time – length of time the combustion blower operates at the end of a burner sequence.
Recommend increasing post purge time for installations with long exhaust venting.
Range = 5-60seconds

15 sec
2-31

Units selection – allows the installer to select US or metric units. Range = ⁰F or ⁰C

⁰F

2-32

External Ignition – future consideration. Range = On or OFF

OFF

Tx Series Installation and Operation Instructions │Trinity

68

Figure 17-5 Lockout Navigation

Figure 17-6 Blocking Error Navigation

Loc – indicates the
boiler is in lockout.

Lockout code - see
Table 17-3 for
description

Clear Lockout –

press and hold the
RESET button to clear
the lockout.

User Menu – press the
UP or Down button to
view boiler parameters.

Installer Menu –

press and hold MENU
and OK buttons to
view settings.

Err – indicates the
boiler has a blocking
error.

Error code - see Table
17-3 for description.

User Menu – press the
UP or Down button to
view boiler parameters.

Installer Menu – press
and hold MENU and
OK buttons to view
settings.

Trinity │Installation and Operation Instructions Tx Series

Lockouts

A lockout is indicated when “Loc” is displayed at the top-left of the screen; the specific lockout code/number is
displayed in large text to the right, see Figure 17-5. Some lockouts (e.g. Loc 1 and 2) are considered “hard
lockouts”, meaning the lockout cannot be cleared by cycling the power supply off and on; the lockout can only be
cleared by pressing and holding the RESET button on the display console. While the boiler is in lockout, the User
and Installer Menus are still accessible as before, and may be accessed to identify boiler sensor readings and
settings.

Blocking Errors

A blocking error is indicated when “Err” is displayed at the top-left of the screen; the specific error code/number
is displayed in large text to the right, see Figure 17-6. Blocking errors are only displayed while a problem exists;
during which time the burner is not permitted to operate. To clear a blocking error the problem must be corrected,
i.e. the blocking error will not be cleared by cycling the power off and on, or by pressing the RESET button.
While the blocking error is display, the User and Installer Menus are still accessible as before, and may be
accessed to identify boiler sensor readings and settings.

69

Figure 17-7 Fill – Low Water Pressure

Code

Description

Loc 1

Ignition Error – three unsuccessful ignition attempts in a row; perform the following checks:

1. Check venting for blockages.

2. Check condensate trap from proper draining.

3. Static gas pressure – if insufficient check gas supply-lines and regulator.

4. Gas pressure during ignition – if the static gas pressure is sufficient, check pressure during ignition

sequence, i.e. when gas valve opens.

a. If pressure drops below minimum (4” for NG / 8” for LP), check gas supply-line and regulator.
b. If pressure does not move, verify 120VAC at valve during ignition; if no power, check wiring

– replace control; if power is present – replace gas valve.

c. If pressure drops slightly – proceed to next step

5. Unit ignites but immediately goes out – check flame sensor (clean or replace) and flame sensor

cable, clean combustion chamber, replace control. If a combustion analyzer is available, adjust
throttle screw out 1 turn – check/adjust combustion once unit is operational.

6. Unit fails to ignite – check spark electrode and cable (replace). Verify the spark electrode is

arcing. WARNING!! – maintain clearance from ignition components while the power is on to
avoid risk of severe electrical shock.

7. Unit ignites and runs – check combustion at maximum and minimum modulation rates.

Loc 2

Gas Valve Circuit Fault (Safety) – control has sensed a fault in the gas valve electrical circuit, check for a
loose connection in the gas valve wiring harness. Also see “Loc 5”.

Loc 3-4

Controller Malfunction – contact NTI, replace controller.

Loc 5

Limit Circuit Open (Safety) – control has sensed a fault in the safety limit circuit; check the following:

1. External Limit (Purple wire) – if an external limit device (i.e. LWCO) is connected to the purple

wire at the field wiring terminal, check to ensure it has not tripped, and that it is wired correctly.

2. Internal Limit (Heat Exchanger Thermal Fuse) – the heat exchanger is equipped with a normally

closed thermal fuse; the fuse opens when the heat exchanger gets too hot. If the fuse is open,
contact NTI [see Figure 19-1(a), item 48].

Loc 6-9

Controller Malfunction – contact NTI, replace controller.

Loc 10

Supply Sensor Fault – controller has sensed an invalid reading at the Supply/Outlet sensor; check cable,
then replace sensor [see Figure 19-1(a), item 15].

Loc 11

Uncorrected Blocking Error – a blocking error (Err) has lasted for 20 consecutive hours.

Loc 12

Incorrect Fan Speed – measured fan speed is not reaching target fan speed within 60 seconds. Check
wiring to fan, replace fan.

Loc 13-26

Controller Malfunction – contact NTI, replace controller.

Loc 27

Flame present 10 seconds after closing gas valve – verify flame is going out immediately following the
end of a burner demand; check flame sensor (replace); check condensate drain for blockages; increase post
purge setting (Installer Menu setting 2-30).

Water Pressure

FILL – indicates the

water pressure is too
low.

Tx Series Installation and Operation Instructions │Trinity

Fill – Low Water Pressure

The Tx boiler is equipped with a water pressure sensor located in the return piping inside the boiler cabinet, see
Figure 19-1(d), item 24 for sensor location; the reading from the sensor is displayed on the Main Screen, see
Figure 17-2. If the control senses a pressure below 7psi, burner operation is inhibited and “FILL” is displayed on
the screen, see Figure 17-7. As long as the water pressure is above 3psi the circulators will be permitted to
operate; otherwise they are only operated 5 seconds every minute.

Table 17-3 Lockout and Error Code Descriptions

70

Code

Description

Loc 28

Flame present before ignition – check flame sensor (replace); check condensate drain for blockages;
increase post purge setting (Installer Menu setting 2-30).

Loc 29 & up

Controller Malfunction – contact NTI, replace controller.

Err 45-51

Controller Malfunction – contact NTI, replace controller.

Err 52

Incorrect Field Wiring – check electrical connections to field terminal strip; ensure the Thermostat is
connected to terminals 7 and 8.

Err 53

Controller Malfunction – contact NTI, replace controller.

Err 54

Flame detected out of sequence – check/replace flame sensor; check flame sensor wiring; check
condensate drain for blockages; replace controller.

Err 55-60

Controller Malfunction – contact NTI, replace controller.

Err 61

Return Sensor Error – check wiring to return sensor; replace sensor [see Figure 19-1(d), item 24].

Err 62-64

Controller Malfunction – contact NTI, replace controller.

Err 65

Incorrect Polarity – controller has sensed reversed polarity of the 120VAC power supply; check field
wiring to L2 NEUTRAL (terminals 12 &13) and L1 120VAC (terminal 14). There should be 120VAC
potential between L1 120VAC and ground, and 0VAC potential between L2 NEUTRAL and ground.

Err 66

Incorrect Frequency – the controller accepts a line voltage frequency of 60Hz ± 2%; if outside this range
the controller may be damaged or function incorrectly. If using a generator as a power source, install a UPS
(uninterruptible power supply) between the generator and boiler.

Err 67

Faulty Earth Ground – check grounding of boiler and power supply; replace controller.

Err 68-71

Controller Malfunction – contact NTI, replace controller.

Err 72

Supply Sensor Open – check wiring to supply sensor; replace sensor [see Figure 19-1(a), item 15].

Err 73

Return Sensor Open – check wiring to return sensor; replace sensor [see Figure 19-1(d), item 24].

Err 74-77

Controller Malfunction – contact NTI, replace controller.

Err 78

Flue Sensor Open – check wiring to flue sensor; replace sensor [see Figure 19-1(d), item 24].

Err 79

Controller Malfunction – contact NTI, replace controller.

Err 80

Supply Sensor Shorted – check wiring to supply sensor; replace sensor [see Figure 19-1(a), item 15].

Err 81

Return Sensor Shorted – check wiring to return sensor; replace sensor [see Figure 19-1(d), item 24].

Err 82-85

Controller Malfunction – contact NTI, replace controller.

Err 86

Flue Sensor Shorted – check wiring to flue sensor; replace sensor [see Figure 19-1(d), item 24].

Err 87 & up

Controller Malfunction – contact NTI, replace controller.

Att 3

DHW Sensor Open – controller has sensed an open circuit at the DHW tank sensor; check wiring to
terminals 3 and 6 and tank sensor. If no tank sensor is being used, set DHW Mode (setting 2-08) to the
appropriate setting; see Table 17-2.

Att 4

DHW Sensor Shorted – controller has sensed a short circuit at the DHW tank sensor; check wiring to
terminals 3 and 6 and tank sensor. If no tank sensor is being used, set DHW Mode (setting 2-08) to the
appropriate setting; see Table 17-2.

Att 6

Warm Weather Shutdown (WWSD) Active – when the outdoor temperature (menu reading 1-08)
exceeds the WWSD setting (menu setting 2-04), “Att 6” is displayed during central heat demands, and the
boiler only responds to DHW demands. To avoid this error, increase menu setting 2-04.

Att 7

Service Reminder – occurs every 365 days; service the boiler and clear the warning by adjusting menu
setting 2-16 to “OFF”.

FILL

Low Water Pressure – increase system water pressure to a minimum of 12psi. If water pressure reading at
the external pressure gauge exceeds 15psi, inspect water pressure sensor and cable – replace water pressure
sensor [see Figure 19-1(d), item 24].

Notes:

1

While displaying a lockout or blocking error, the User and Installer Menus can be accessed to view the status of boiler

sensors and settings.

2

Blocking errors (Err) and some lockouts (Loc) will not clear until the fault is correct.

3

Some lockouts (Loc) can only be cleared by holding the RESET button on the display console.

Trinity │Installation and Operation Instructions Tx Series

71

tYPE – indicates that the
Appliance Type setting is
ready to be adjusted.

Step 2a – set
Appliance Type per
Table 17-4.

Step 2b – once correct
Appliance Type setting is
displayed, press OK to
enter the value.

Step 1a – turn power off

Step 1b – while holding the

UP and DOWN buttons, turn
the power on; continue to
hold until tYPE is displayed.

Model

Gas

Appliance

Number

Model

Gas

Appliance

Number

Tx51

NG

1

Tx101

NG & LP

3

LP

6

Tx151

NG & LP

4

Tx81

NG & LP

2

Tx151C

NG & LP

5

Figure 17-8 Appliance Selection

Tx Series Installation and Operation Instructions │Trinity

Controller Replacement Instructions

This section provides important information necessary for successfully replacing the boiler controller, NTI P/N
84712, in the event the original controller fails. The replacement controller must be field configured to operate on

the Tx boiler model it is being installed on; this is accomplished by adjusting the controller’s Appliance Type

setting.
Appliance Type – the Appliance Type setting is retained in the boiler controller; the setting determines certain

operating characteristics specific to a particular boiler model, such as combustion blower RPM (i.e. firing rate) ;
see Table 17-4 for a list of Appliance Types and corresponding boiler models.

Table 17-4 Appliance Type Setting by Boiler Model

Replacement Procedure – the replacement controller is factory set with an Appliance Type setting of zero (0);

upon replacement of the control the display will prompt you to set the appliance type, i.e. “tYPE 0” will
automatically be displayed on the screen (see Notice below). Adjust to the applicable Appliance Type setting
(see Table 17-4) using the UP & DOWN buttons; press the OK button to enter the value. Check the appliance
setting via Installer Menu setting 2-11; make sure it matches the correct boiler model as per Table 17-4. Set the
remainder of the control settings as desired. Verify proper boiler operation for DHW and Central Heat demands.

If “tYPE 0” does not automatically display upon replacing the controller, the Appliance

Type setting must be adjusted using the “Appliance Selection Method” detailed below.

Appliance Selection Method – to change the Appliance Type setting, perform the following steps:

1. Turn the power off; while holding the UP and DOWN buttons, turn the power on using power switch on the

display console; see Figure 17-8. Continue holding the UP and DOWN buttons until “tYPE 0” is displayed on
the screen, then release the UP and DOWN buttons.

2. Increase the setting by press the UP button. When the correct setting is displayed, see Table 17-4; press the

OK button to enter the value.

3. Wait for a minimum of 1 minute, then cycle the power off and on.

4. Check the appliance setting via Installer Menu setting 2-11; make sure it matches the correct boiler model as

per Table 17-4. Set the remainder of the control settings as desired. Verify proper boiler operation on
Domestic Hot Water and Central Heat demands.

72

Trinity │Installation and Operation Instructions Tx Series

18.0 TROUBLESHOOTING

Servicing the Boiler

 Disconnect or shutoff all energy sources to the boiler: 120VAC power, water and gas.
 Identify and mark wires before disconnecting or removing them.
 Never bypass electrical fuses or limit devices except temporarily for testing.
 Use proper personal protective equipment (PPE) i.e. eye protection, safety footwear.

These procedures should only be performed by qualified service personnel, when abnormal operation of the
boiler is suspected. The boiler incorporates a sophisticated microprocessor based control which normally
responds appropriately to varying conditions. If the boiler operation appears to be incorrect, or it is not
responding at all to a demand for heat, the following is suggested to determine and correct the problem.

Resistance (Ohms) and Continuity.

Diagnosing an Inoperative Boiler

1) Blank Display – perform the following steps:

 Ensure the boiler service switch located on the front of the boiler is in the ON (1) position.
 Ensure the main service switch (if applicable) is in the ON position.
 Ensure the circuit breaker in the electrical panel supplying power to the boiler in on.
 Measure across boiler terminals 13 and 14 (L1 120VAC and L2 NEUTRAL) for 120VAC, see Figure 12-2.

If 120VAC is present, check fuse located on the boiler controller, see Figure 18-1. If 120VAC is not present,
check wiring between the boiler and electrical panel for poor connections.

 Check the electrical connection to the display – connector is located behind display.

2) Display Normal but no heat to radiators – perform the following steps:

 Ensure there is a heat call from the thermostat (radiator symbol on the display will flash during a thermostat

demand). If uncertain about thermostat operation, place a jumper between the boiler’s Thermostat terminals.
If the radiator symbol does not display, check outdoor sensor reading (User Menu reading 1-08), and
compare to the warm weather shutdown setting (Installer Menu setting 2-04); central heat call will not
activate if the outdoor temperature is above the warm weather shutdown setting.

 If the radiator symbol is flashing, but the boiler is not firing, compare the boiler outlet temperature

(temperature displayed on the main screen) with the Current target temp (User Menu reading 1-01). Boiler
will not fire until the outlet temperature drops below the Current target temp by the CH setpoint differential
(Installer Menu setting 2-02 – default setting = 9ºF).
o Ensure the central heating pump(s) is running – if not ensure it is wired to pump output CH PUMP or

BOILER PUMP.

o If Current target temp is insufficient, increase CH setpoints (Installer Menu settings 2-01 and 2-05).

 If the radiator symbol is on but not flashing, and the faucet symbol is flashing, then the boiler is actively

servicing a DHW demand; at which time no hot water will go to the radiators. If condition continues,
consider increasing the DHW setpoint (Installer Menu setting 2-07), or decreasing the DHW priority time
(Installer Menu setting 2-09).

3) Display Normal but no DHW – perform the following steps:

 Tx Combi (Tx151C):

o Verify DHW Mode is set to 5(Installer Menu setting 2-08).
o Verify there is DHW flow – check DHW flow rate (User Menu reading 1-05); boiler goes to DHW mode

when the flow exceeds 0.3gpm. If flow is insufficient, check water supply and DHW piping; check Y­strainer for blockage. Check wiring to flow sensor – replace flow sensor if necessary.

o Compare DHW setpoint (User Menu reading 1-04) with DHW temp (User Menu reading 1-03); burner

fires when the DHW temp drops below DHW setpoint, if the flow exceeds 0.3gpm. If necessary increase

Observe the following precautions when servicing the boiler. Failure to comply with

these may result in fire, property damage, serious injury or death.

Before undertaking any troubleshooting procedures it is highly recommended to have

available a digital multimeter(s) capable of measuring AC and DC volts, Amperes,

73

Tx Series Installation and Operation Instructions │Trinity

DHW setpoint (Installer Menu setting 2-07) – 120 to 140ºF recommended.

o If the radiator symbol is flashing on the display, the DHW priority time may have expired. Cycle power

and consider increasing the DHW priority time (Installer Menu setting 2-09).

 Indirect Tank with Tank Sensor:

o Verify DHW Mode is set to 1(Installer Menu setting 2-08).
o Verify there is a Tank sensor wired to COMMON and DHW (boiler terminals 3 and 6), see Figure 12-2.

Tank sensor temperature, DHW temp, is viewed from User Menu reading 1-03.

o Compare DHW setpoint (User Menu reading 1-04) with the DHW temp (User Menu reading 1-03). DHW

Tank demand is generated when the DHW temp drops 4ºF below the DHW setpoint; after which burner
demand starts when the boiler outlet temperature (displayed on Main Screen) drops below the Current

target temp (User Menu reading 1-01) by 15ºF . Current target temp for a DHW Tank demand is equal to
DHW setpoint + 40ºF; if necessary increase DHW setpoint (Installer Menu setting 2-07) – 130 to 140ºF

recommended.

o If the radiator symbol is flashing on the display, the DHW priority time may have expired. Cycle power

and consider increasing the DHW priority time (Installer Menu setting 2-09) and/or DHW setpoint
(Installer Menu setting 2-07).

o If the faucet symbol is flashing on the display, verify the DHW circulator is operating – DHW circulator

should be wired to DHW PUMP and L2 NEUTRAL (boiler terminals 9 and 12/13); see Figure 12-2.

o Verify plumbing is in accordance with Figure 10-3 or 10-4.

 Indirect Tank with Tank Thermostat:

o Verify DHW Mode is set to 2 (Installer Menu setting 2-08).
o Verify there is a Tank thermostat wired to COMMON and DHW (boiler terminals 3 and 6), see Figure

12-2.

o Verify there is a demand from the thermostat; when the demand is on, DHW temp (User Menu reading 1-

03) will indicate “On” (or 242⁰F/117⁰C); when demand is off, DHW temp will indicate “Off” (or 14⁰F/­10⁰C). If uncertain about thermostat operation, place a jumper between terminals 3 and 6; the faucet
symbol will flash on display when there is a DHW demand.

o Compare DHW setpoint (User Menu reading 1-04) with the boiler outlet temperature (displayed on Main

Screen); burner demand starts with the boiler outlet temperature drops below the DHW setpoint by 15ºF.
If necessary increase DHW setpoint (Installer Menu setting 2-07) – 160 to 190ºF recommended.

o If the radiator symbol is flashing on the display, the DHW priority time may have expired. Cycle power

and consider increasing the DHW priority time (Installer Menu setting 2-09) and/or DHW setpoint
(Installer Menu setting 2-07).

o If the faucet symbol is flashing on the display, verify the DHW circulator is operating – DHW circulator

should be wired to DHW PUMP and L2 NEUTRAL (boiler terminals 9 and 12/13); see Figure 12-2.

o Verify plumbing is in accordance with Figure 10-3 or 10-4.

4) Display Normal but DHW is not hot enough – perform the following steps:

 Increase DHW setpoint (Installer menu setting 2-07):

o Tx Combi (Tx151C) – recommended setting = 120 to 140ºF.
o Indirect Tank with Tank Sensor (DHW Mode = 1) – recommended setting = 130 to 140ºF.
o Indirect Tank with Tank Thermostat (DHW Mode = 2) – recommended setting = 160 to190ºF.

 Tx Combi (Tx151C) – DHW flow rate is too great; compare DHW flow rate (User Menu reading 1-05) with

Tables 11-1 and 11-2. If necessary, restrict overall DHW flow rate.

 Indirect Tank – verify plumbing is in accordance with Figure 10-3 or 10-4.

5) Display indicates an error (Err), lockout (Loc) or warning (Att); reference Table 17-3 in Section 17.0.

74

Figure 18-1 Tx Fuse Location

Table 18-1 Thermistor Resistance vs. Temperature

Temp °F (°C)

Resistance Ohms (Ω)

Temp °F (°C)

Resistance Ohms (Ω)

-22 (-30)

176,133

122 (50)

3,603

-4 (-20)

96,761

131 (55)

2,986

14 (-10)

55,218

140 (60)

2,488

32 (0)

32,650

149 (65)

2,083

41 (5)

25,390

158 (70)

1,752

50 (10)

19,900

167 (75)

1,481

59 (15)

15,710

176 (80)

1,258

68 (20)

12,490

185 (85)

1,072

77 (25)

10,000

194 (90)

918

86 (30)

8,057

203 (95)

789

95 (35)

6,531

212 (100)

680

104 (40)

5,327

230 (110)

506

113 (45)

4,369 - -

Spare Fuse

Operating Fuse, LFT

3.15A – “Slow-blow”

Boiler Controller

Trinity │Installation and Operation Instructions Tx Series

Only replace Tx controller fuse with identical part (LFT 3.15A, 250V “slow-blow”).

Failure to follow this warning may result in component failure or property damage.

75

Figure 19-1(a) Tx Heat Engine and Gas Train

Heat Exchanger, Gas Valve, Blower and Burner Assembly

5

48

20

98

17

17

22

19

91

96

27

27

27

27

30

15

29

97

18

21

24

3

4

36

10

32

31

33

26 9 93

8

79

28

93

14

HX end of

pipe shown

with O-ring

IWC end of

pipe shown

with O-ring

118

16

92

2

5 1 25

47

Tx Series Installation and Operation Instructions │Trinity

19.0 PARTS LIST

For a list of parts that corresponds to the item numbers in the callouts, refer to Table 19-1. Note that some item
numbers may appear more than once in the parts list depending on which model number is being referenced.

Building Owners - Replacement parts are available from your stocking wholesaler. Contact your local Installer
or Wholesaler for assistance with parts.

Wholesalers - Contact NY Thermal Inc. directly when ordering replacement parts, 1-506-657-6000.
Installers - Contact NY Thermal Inc. directly if technical assistance required, 1-800-688-2575.

76

Figure 19-1(b) Tx Cabinet

Cabinet, Vent and Air-Inlet Parts

Figure 19-1(c) Tx Controls

Electrical Housing, Controller, and Display Module

70

70

70

52

23

61

107

74

42

41

49

75

39

73

45

50

74

50

46

95

77

35

37

72

78

77

78

44

Trinity │Installation and Operation Instructions Tx Series

77

Figure 19-1(d) Tx Installation Kit Box

Item

Part #

Description

1

84882

Burner Assembly, c/w door, insulation & gasket (Tx51)

1

84883

Burner Assembly, c/w door, insulation & gasket (Tx81)

1

84884

Burner Assembly, c/w door, insulation & gasket (Tx101)

1

84885

Burner Assembly, c/w door, insulation & gasket (Tx151 & Tx151C)

2

84743

Flue Outlet Gasket (all Tx models)

3

84597

Blower Mounting Screws, M5x12 Hex (all Tx models)

4

82766

Blower Gasket (all Tx models)

5

84909

Blower/Venturi Assembly, 535 (Tx51)

5

84910

Blower/Venturi Assembly, 534 (Tx81)

5

84911

Blower/Venturi Assembly, 533 (Tx101)

5

84912

Blower/Venturi Assembly, 532 (Tx151 & Tx151C)

8

84869

LP Orifice, 3.5mm (Tx51)

8

84870

LP Orifice, 3.8mm (Tx81)

8

84871

LP Orifice, 4.2mm (Tx101)

8

84795

LP Orifice, 5.05 (Tx151 & Tx151C)

9

84713

Gas Valve (all Tx models)

10

84738-1

Ignition Electrode, c/w gasket & cable (all Tx models)

11

84739

Ignition Electrode Gasket

14

84763

Gas Valve Adapter, c/w screws and O-ring (all Tx models)

15

84781

Outlet Sensor, clip-on, c/w retaining clip (all Tx models)

16

84733

O-ring (small), Boiler Inlet/Outlet, 2.76 x 17.72 (Tx51)

16

84735

O-ring (medium), Boiler Inlet/Outlet, 3.2 x 19 (Tx81-151 & Tx151C)

17

84732

Retaining Clip – Boiler Outlet/Inlet Pipe, 18mm (Tx51)

17

84734

Retaining Clip – Boiler Outlet/Inlet Pipe, 19mm (Tx81-151 & Tx151C)

18

84809

Outlet Pipe, 18mm (Tx51)

18

84806

Outlet Pipe, 19mm (Tx81-151)

18

84804

Outlet Pipe, Combi (Tx151C)

19

84474

Auto Air Vent, ½” NPT (all Tx models)

70

61

109

Common

(All Tx Models)

110

38

57

59

110

114

116

115

38

109

115

71

111

117

Heat Only

(Tx51-151)

Combi Only

(Tx151C)

There are 4 different Tx Conversion Kits.
Each kit has a sing l e orifice, decal,
and instructions.

113

112

8

Natural Gas to LP Conversion Kit

119

Tx Series Installation and Operation Instructions │Trinity

Table 19-1 Parts List: Tx Series

78

Item

Part #

Description

20

84780

Flue Sensor (all Tx models)

21

84810

Inlet Pipe, 18mm (Tx51)

21

84807

Inlet Pipe, 19mm (Tx81-151)

21

84805

Inlet Pipe, Combi (Tx151C)

22

84801

Auto Air Vent Adapter (all Tx models)

23

84423

Receptacle, 120VAC (all Tx models)

24

84745

Inlet/Pressure Sensor (all Tx models)

25

84913

Sight Glass, c/w gasket & snap ring (all Tx models)

26

84673

Heat Exchanger, ASME 2+1 (Tx51)

26

84674

Heat Exchanger, ASME 3+1 (Tx81)

26

84675

Heat Exchanger, ASME 4+1 (Tx101)

26

84676

Heat Exchanger, ASME 5+1 (Tx151 & Tx151C)

27

83044-1

Condensate Drain Tube, c/w retaining nut & gear clamps (all Tx models)

28

84914

Brazed Plate Heat Exchanger (Tx151C)

29

84915

Diverter Valve Stepper Motor (Tx151C)

30

83510

Condensate Trap Assembly (all Tx models)

31

84742

Deflector Insulation (all Tx models)

32

84737

Burner Door Gasket, EPDM (all Tx models)

33

84736

Burner Door Ceramic Insulation (all Tx models)

35

84214

Grommet, Diaphragm, ½” (all Tx models)

36

84740-1

Ionization Electrode, c/w gasket & cable (all Tx models)

37

84755

MJ Coupling, 1-1/2 x 1-1/4 (all Tx models)

38

82615

2” Bird Screen (all Tx models)

39

84881

Air Inlet Assembly (all Tx models)

41

84785

Flue Outlet Adapter, PPS/PVC, c/w test plug (all Tx models)

42

84786

Air Inlet Adapter, PPS/PVC (all Tx models)

44

84916

Test Port Plug (all Tx models)

45

84920

Wall Mount Bracket, Top (all Tx models)

46

83505

Gas Line Grommet, ½” IPS (all Tx models)

47

84917

Circulator Cartridge, UPS15-78 (Tx151C)

48

84886

Thermal Fuse (all Tx models) – Contact NTI Tech Support before replacing

49

84440

Air Vent Grommet, 1875 (all Tx models)

50

84872

Wall Mount Bracket, Bottom (all Tx models)

52

84764-1

Display Assembly, 210LB (all Tx models)

57

84479

Elbow, Street, Brass, ¾ (Tx51-151)

59

82759

Tee, Brass, 1 x 1 x 3/4" (Tx51-151)

61

84712

Controller, 210MN (all Tx models)

63

Tx Wiring Harness

Wiring Harness Complete (all Tx models)

67

84918

Fuse, LFT 3.15A, 250V (all Tx models)

70

Control Panel Sheet Metal (all Tx models)

71

83604

Outdoor Sensor, 10K (all Tx models)

72

Front Cover (all Tx models)

73

Right Side (all Tx models)

74

Left Side (all Tx models)

75

Top (Tx51)

75

Top (Tx81)

75

Top (Tx101)

75

Top (Tx151)

75

Top (Tx151C)

77

84726

Heat Exchanger Support Rail, c/w screws (Tx51)

Trinity │Installation and Operation Instructions Tx Series

79

Item

Part #

Description

77

84727

Heat Exchanger Support Rail, c/w screws (Tx81 ASME)

77

84728

Heat Exchanger Support Rail, c/w screws (Tx101 ASME)

77

84729

Heat Exchanger Support Rail, c/w screws (Tx151 & Tx151C ASME)

78

84730

Heat Exchanger Support Front Clip (all Tx models)

79

84919

Gas Valve to Venturi Gasket (all Tx models)

91

84907

DHW Temperature/Flow Sensor, VFS (Tx151C)

92

84749

O-ring (large), Combi Block Inlet/Outlet, 4 x 17 (Tx151C)

93

84921

Retaining Clips, Combi Block Inlet/Outlet (Tx151C)

95

84095

Plug, Dome, 7/8” (all Tx models)

96

84922

DHW Fittings, Combi Block, ¾” NPT (Tx151C)

97

84923

CH Fittings, Combi Block, ¾” NPT (Tx151C)

98

84924

Retaining Clip, Air Vent Adapter (all Tx models)

107

84422

Rocker Power Switch (all Tx models)

109

13701

Relief Valve, 30psi (all Tx models)

110

84090

Pressure Gauge, Stem Mount, 60psi (Tx51-151)

110

84859

Pressure Gauge, Back Mount, 60psi (Tx151C)

111

82616

3” Bird Screen (all Tx models)

112

84925

Natural Gas to LP Conversion Instructions (all Tx models)

113

84867

LP Conversion Decal (all Tx models)

114

83645

Y-Strainer, Brass, ¾”, 100M Screen (Tx151C)

115

82368

Compression Gasket, Rubber (Tx151C)

116

84808

Low Loss Header Pipe, FIDT (Tx151C)

117

84929

Wall Mount Bracket, L-shaped (all Tx models)

118

84744

IWC - Integrated Water Control, Grundfos (Tx151C)

119

84867-1

NG to LP Conversion Kit, Tx51 (2+1)

119

84867-2

NG to LP Conversion Kit, Tx81 (3+1)

119

84867-3

NG to LP Conversion Kit, Tx101 (4+1)

119

84867-4

NG to LP Conversion Kit, Tx151 & Tx151C (5+1)

Tx Series Installation and Operation Instructions │Trinity

80

Trinity │Installation and Operation Instructions Tx Series

NY Thermal Inc. 65 Drury Cove Road Saint John, NB E2H 2Z8 Canada

Technical Assistance: 1-800-688-2575

Website: www.nythermal.com

Fax: [phone]