H2O HC Series, HC 600, HC 1500, HC 1000, HC 2000 Installation, Operation And Maintenance Manual

D-VAC Sales Inc.

D-VAC Sales Inc. Email: [e-mail] Tel: [phone] www.dvachvac.com

MASSAPEQUA, NY

EMAIL: [e-mail] TEL: [phone]

HC Series

Gas-Fired Stainless Steel Boilers and Water Heaters

INSTALLATION, OPERATION AND MAINTENANCE MANUAL

WARNING: If the information in this

manual is not followed exactly, a fire

or explosion may result causing
property damage, personal injury or
loss of life.

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

WHAT TO DO IF YOU SMELL GAS

 Do not try to light any appliance.
 Do not touch any electrical switch;

do not use any phone in your

building.

 Immediately call your gas supplier

from a neighbor’s phone. Follow
the gas supplier’s instruction.

 If you cannot reach your gas

supplier, call the fire department.
Installation and service must be
performed by a qualified installer, service
agency or the gas supplier.

HC SERIES GENERAL SPECIFICATIONS

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H2O BOILER HC SERIES IOM Manual

WARNING: Fire or Explosion Hazard

Improper configuration can cause fuel buildup and
explosion. Improper user operation may result in
property loss, severe physical injury, or death.
Any changes to safety-related configuration
parameters must only be done by experienced
and/or licensed burner/boiler operators and
mechanics. If any odor of gas is detected, or if the
gas burner does not appear to be functioning in a

.
Do not shut off the power switch. Contact your
heating contractor, gas company, or factory
representative.

WARNING: Carbon Monoxide Hazard

Improper adjustment of the burners may lead to
poor combustion quality, increasing the amount of
carbon monoxide produced. Excessive carbon
monoxide levels may lead to personal injury or
death.

WARNING: Electrical Shock Hazard

Electrical shock can cause severe injury, death or
property damage. Disconnect the power supply
before beginning installation or changing the
wiring to prevent electrical shock or damage to
the equipment. It may be necessary to turn off
more than one power supply disconnect. All
electrical wiring is to be done in accordance with
local codes, or in the absence of local codes, with:

1) The National Electrical Code ANSI/NFPA No.
70 - latest Edition, or 2) CSA STD. C22.1
“Canadian Electrical Code - Part 1.” This
appliance must be electrically grounded in

Note: This product must be installed and serviced by a professional service technician,

qualified in hot water boiler and heater installation and maintenance. Improper installation
and/or operation could create carbon monoxide gas in flue gases which could cause serious
injury, property damage, or death. Improper installation and/or operation will void the
warranty.

Warning: For proper operation of a spa or hot tub the following safety rules should be observed:

Spa or hot tub water temperature should never exceed 104º F (40º C). A temperature of

100º F (38º C) is considered safe for an adult. Special caution is suggested for young

Drinking alcoholic beverages before or during hot tub or spa use can cause drowsiness,

Pregnant women should be cautious. Soaking in water above 102º F (39º C) can cause
fetal damage during the first three months of pregnancy. Pregnant women should respect

Before entering the spa or hot tub, the water temperature should be checked with an
accurate thermometer. Spa or hot tub thermostats may have an inaccuracy, as high as 4º

Persons with medical history of heart disease, circulatory problems, diabetes or blood

 Persons taking medications, which induce drowsiness, should not use spas or hot tubs.

Note: The installation must conform with one or more of the following, as applicable:

The National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or CSA B149.1, Natural
Gas and Propane Installation Code.

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1) Local codes or, in the absence of local codes,

2)



children.



which could lead to unconsciousness and subsequently resulting in drowning.



the 100º F (38º C) maximum rule.



F in regulating the water temperature.



pressure should obtain their physician’s advice before using spas or hot tubs.

accordance with these codes.

normal manner, close the main gas shutoff valve

HC SERIES GENERAL SPECIFICATIONS

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H2O BOILER SERIES IOM Manual

Warning:

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.

Warning:

Do not bypass any of the instruments in the safety loop. Doing so may cause

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serious damage to the unit and its surroundings.

HC SERIES GENERAL SPECIFICATIONS

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HC SERIES GENERAL SPECIFICATIONS

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Table of Contents

HC SERIES GENERAL SPECIFICATIONS ................................................................................................................ vii

HC SERIES GENERAL LAYOUT & DIMENSIONS ................................................................................................. viii

SECTION 1: INTRODUCTION ...................................................................................................................................... 1

1.1 Boiler/Water Heater Heat Exchanger .............................................................................................................. 2

1.2 Control System................................................................................................................................................ 3

1.3 Safety Features ................................................................................................................................................ 3

1.4 Gas Lines ........................................................................................................................................................ 5

1.4.1 Pilot Gas Line ............................................................................................................................................. 5

1.4.2 Main Gas Line ................................................................................................................................ ............ 5

1.4.3 Gas Manifold and Control Assembly Tests ................................................................................................ 6

1.4.4 Code Compliance ....................................................................................................................................... 6

1.5 Freeze Protection and Storage ......................................................................................................................... 7

1.6 Water Treatment ............................................................................................................................................. 7

SECTION 2: INSTALLATION ....................................................................................................................................... 8

2.1 Water Heater/ Boiler Package ......................................................................................................................... 9

2.2 Removal of Existing Boiler ........................................................................................................................... 10

2.3 Clearance from Combustible Material .......................................................................................................... 11

2.4 Location ........................................................................................................................................................ 12

2.5 Relief Valve piping ....................................................................................................................................... 13

2.6 Water Connection ......................................................................................................................................... 13

2.6.1 Potable water heater connection ............................................................................................................... 14

2.6.2 Piping Arrangement ............................................................................................................................... 14

2.7 Condensate Line ............................................................................................................................................ 17

2.8 Gas Line Connections ................................................................................................................................... 17

2.9 Electrical connection ..................................................................................................................................... 18

2.10 Vent Connection ........................................................................................................................................... 18

2.10.1 Suggested Single wall Vent system ...................................................................................................... 19

2.10.2 Vent Sizing ........................................................................................................................................... 22

2.11 General Instructions ...................................................................................................................................... 23

SECTION 3: OPERATION ........................................................................................................................................... 25

3.1 Sequence of Operation .................................................................................................................................. 26

3.1.1 Safety Loop .............................................................................................................................................. 26

3.1.2 Pre-Purge .................................................................................................................................................. 26

3.1.3 Pilot Flame ................................................................................................................................................ 27

3.1.4 Main Flame ............................................................................................................................................... 27

3.1.5 Continuous Operation ............................................................................................................................... 28

3.2 PRE-COMMISSIONING ............................................................................................................................. 29

3.3 Commissioning ............................................................................................................................................. 30

3.4 Boiler Capacity and recovery rate ................................................................................................................. 31

HC SERIES GENERAL SPECIFICATIONS

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SECTION 4: MAINTENANCE ..................................................................................................................................... 33

4.1 Maintenance Schedule .................................................................................................................................. 34

4.2 General Procedure ......................................................................................................................................... 34

4.3 Service Notes ................................................................................................................................................ 36

4.2 Troubleshooting ............................................................................................................................................ 37

Technical Data ................................................................................................................................................................ 39

Control System Schematic.......................................................................................................................................... 39

Reports........................................................................................................................................................................ 41

HC SERIES GENERAL SPECIFICATIONS

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H2O BOILER HC SERIES IOM Manual

HC 600

HC 1000

HC 1500

HC 2000

HC 2500

Input

BTU/hr

kW

BHP

600,000

176
236

1,000,000

293
393

1,500,000

440
590

2,000,000

586
785

2,500,000

733
983

Output

BTU/hr

kW

BHP

570,000

167
224

950,000

278
373

1,425,000

418
560

1,900,000

557
747

2,375,000

696
933

Boiler Eff. Full load

%

95

95

95

95

95

Electrical Rating

V/Ph/Hz

115/1/60

115/1/60

115/1/60

115/1/60

115/1/60

Heating Surface

Ft267

105

172

200

229

Shipping Weight1 (approx.)

lbs

550

750

950

1,350

1,500

Water Content

USG

12

17

26

30

34

Minimum Water Flow Rate

USGPM

12

19

24

24

32

Inlet Gas Pressure2

Inches WC

7 - 14

Flue Duct Material

Stainless Steel (air tight, corrosion resistant)

Max Working Pressure

PSIG

160

Max Working Temp.

°F

210

Min Inlet Water Temp.

°F

Any temperature above freezing point

Min Service Clearance

Inches (cm)

Front 24” (61), Top (40), Side 0

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HC SERIES GENERAL SPECIFICATIONS

Table 1: HC Series General Specifications

1. Dry weight of the unit.

2. Inlet gas pressures are standard values. Refer to submittal drawings for minimum requirements for different configuration.

HC SERIES GENERAL LAYOUT & DIMENSIONS

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H2O BOILER HC SERIES IOM Manual

Model

“A” in.

(mm)

“B” in.

(mm)

“C” in.

(mm)

“D” in.

(mm)

“E” in.

(mm)

HC 600

35(890)

40.5(1,030)

20.5(521)

60(1,524)

40.5(1029)

HC 1000

35(890)

40.5(1,030)

26(661)

66(1,676)

40.5(1029)

HC 1500

35(890)

45(1,150)

35.6(905)

75.6(1,920)

40.5(1029)

HC 2000

35(890)

45(1,143)

37.75(959)

81.75(2,076)

40.5(1029)

HC 2500

35(890)

45(1,143)

44(1,118)

86(2,184)

40.5(1029)

Model

Ø Gas

Inlet “G”

in.

Ø Water

Inlet “H”

in.

Ø Water

Outlet “I”

in.

Ø Flue

Vent “J”

in.

Ø Water

Drain “K”

in.

Ø Cond.

Drain “L”

in.

HC 600

1 2 2 7 ¾ ¾ HC 1000

1 2 2 9 ¾ ¾ HC 1500

2 2 2

10 ¾ ¾

HC 2000

2 3 3

10 ¾ ¾

HC 2500

2 3 3

12 ¾ ¾

Note: Depth of the unit may vary

depending on the burner selected.

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HC SERIES GENERAL LAYOUT & DIMENSIONS

Figure 1: General layout of the HC series boilers

Table 2: HC series dimensions

SECTION 1: INTRODUCTION

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SECTION 1: INTRODUCTION

SECTION 1: INTRODUCTION

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1.1 Boiler/Water Heater Heat Exchanger

The H2O HC series is a gas-fired water tube boiler and water heater with nominal input
rating ranging from 600,000 to 2,500,000 Btu/hr. Each unit consists of several stainless
steel coiled tubes (SA-249 Type 316L), 1” diameter and 0.049” wall thickness. The coils are
held parallel vertically by means of stainless steel ready rods and adjustment nut assemblies. The
inlets and outlets of the coils are welded to the manifolds pipes of the boiler.

Figure 2: HC Series Boiler

The heat exchanger assembly consists of a ceramic refractory, insulation plate and support ring
prevent hot gas escaping through the rear coil. The front hub and the front coil are connected and
support a high performance gas burner. The weight of the burner is counter balanced by the heat
exchanger.

The exact mechanism of heat exchange is an engineering phenomenon, involving combination of
counter flow, condensation heat recovery, fouling factors, and two-phase conditions. The working
of heat exchanger is a simple process. The gas burner ignites the gas and air mixture inside the
combustion chamber (the central space of the four coils). The hot gas particles cool and condense
as they pass through the gaps of the coils. The flue particles are gathered in the boiler chamber
(space outside the coils and within the liners) and exit through the chimney. The water flows in
the opposite direction of gas. Feed water enters the each coil at the perimeter of the heat
exchanger. The water picks up heat gradually as it circulates through the coil tubes and exits at the
center (near the central hubs). The counter flow design reduces the impact of thermal shock and
increases the heat exchanger life. The flue condensate is drained through a fitting at the bottom
right of the boiler.

SECTION 1: INTRODUCTION

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Figure 3: Patented radial pulse heat exchanger

Boiler’s heat exchanger is designed for flue gas condensation, for a higher thermal efficiency.
Flue condensation will occur if the temperature of the inlet water is below dew point, usually 120
degrees Fahrenheit. Because the flue condensate is a corrosive element, the internal structure of
the boiler is constructed out of stainless steel 304/316L or better to offer the highest service life.
Corrosion related failures are the typical problems which can be managed through a scheduled
progressive inspection and maintenance program.

1.2 Control System

The boiler/water heater control module consists of an “Individual Boiler/Water Heater Control

Module”, or the “BMS” (Building Management System) signal input module as an option.

With the “Individual Boiler/Water Heater Control Module”, the unit’s operation is governed by the

desired outlet (hot water) temperature. Using a digital, high precision temperature controller, the
owner will identify the required hot water temperature. A temperature sensor installed on the
boiler/water heater outlet manifold continuously measures the outlet water temperature. A
servomotor controlling the gas butterfly valve and the air damper allows for throttling of the
air/gas mixture flowing into the burner. For as long as the set temperature is above that of the
outlet water, the boiler/water heater operates at maximum output capacity.

1.3 Safety Features

Each H2O BOILER HC series boiler and water heater is equipped with a number of safety features.

 Low Water Cut Off Switch: One “McDonnell & Miller” low water cut off switch is

installed on the outlet manifold. It prevents the burner from firing when water level drops.
When water reaches the LWCO position, the burner will fire.

 Flame Sensor: Every Burner type is equipped with an Ultraviolet flame detector or a

flame probe sensor. This is connected to the burner controller, and is installed inside the

SECTION 1: INTRODUCTION

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H2O BOILER HC SERIES IOM Manual

Notes:

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burner head. At any time after the main gas valve is opened, if flame is not detected for a
period longer than 4 seconds, the burner controller will be deactivated and the main gas
valve will immediately close.

 High Temperature Limit: Each unit is equipped with a “Honeywell” high temperature

limit switch. If outlet water temperature exceeds the temperature set on this switch, switch
will open and the burner controller will be deactivated and the gas valve will immediately
close.

 Air Pressure Switches: Every Burner type is equipped with a low air pressure switch is

installed on the air inlet of the blower and measures air pressure entering the burner. If the
combustion air pressure drops by more than 20% below the nominal air pressure (minimum
pressure of 0.4” wc) for any reason such as air inlet obstruction or exhaust obstruction, the
burner controller will be deactivated and the main gas valve will immediately close.

 Relief Valve: A safety relief valve with prescribed nominal pipe size of 3/4" to 1 1/4”

valve inlet/outlet, at 150 psig relief pressure, is installed on the water outlet manifold and
supplied as standard equipment. When the boiler or water heater is used in heating
applications having working pressures in the range 40–160 psig, an appropriate pressure
relief valve should be installed.

 Gas Pressure Switch: One manual reset low gas pressure switch is installed on the gas

train in between the gas pressure regulator and the first safety shut off valve. If the line
pressure drops below 7” wc, the switch will open and the unit will immediately shut down.
One high gas pressure switch is also installed. If the gas manifold pressure increases above
the pressure on the boiler label, the switch will open and the unit will immediately shut
down. High and Low pressure switches can be also installed directly on the available ports
of the safety shut-off gas valve. Refer to figure 6 for a typical gas train configuration.

 Flow Switch: One Flow switch is installed on the outlet manifold. Flow switch has a very

important role. Flow switch is a part of the safety loop, and during normal operation of the
boiler, it will be in close position. When flow rate of the water drops below the minimum
required flow rate, Flow switch will open and stop the burner immediately. When water
flow rate reaches the minimum flow rate for the specific boiler, Flow switch will close up
and burner will automatically restart.

Flow switch installation

 Additional flow switch is to be installed on the inlet piping of the boiler (by

user).

 Flow switch’s paddle length is sized according to the manufacturer’s instruction

for the intended pipe size.

 Contact H2O BOILER for installation instruction of the Flow switch.

SECTION 1: INTRODUCTION

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1.4 Gas Lines

1.4.1 Pilot Gas Line

Referring to Figure 5, gas from the main supply line flows at the maximum pressure of 14” wc,
through the manual valve into the pilot line. From the pressure regulator it will then flow through
the safety shut off valves into the burner. The pilot pressure regulator is adjusted such that gas
flows within 2” – 5” wc pressure into the first safety shut off valve. If pilot flame is not
established within 5 seconds of the ignition trial time, the flame safeguard will shut off the pilot
safety gas valve(s).

The pilot flame will ignite the air/gas mixture flowing through the burner within 5 seconds of the
mixture flowing into the burner. In some burner models, a direct ignition system is being used
which eliminates the need for pilot gas train.

Figure 4: Pilot gas train

1.4.2 Main Gas Line

Referring to Figure 6, gas from the main supply line flows at a maximum pressure of 14” wc,
through the manual gas valve into the main gas line. From the pressure regulator it will then flow
through the two safety shut off valves, into the second manual shut off valve. Finally gas flows
through the gas adjustment butterfly valve into the burner where it is ignited by the pilot flame.
The pressure regulator is adjusted such that the manifold gas pressure remains within 0.2 – 3.0”
wc. Signals from the temperature controller are sent to the servomotor, which controls the opening
of the butterfly valve and the air damper. Subsequently, the valve and damper are proportionately
closed or opened in order to decrease or increase the air/gas mixture flow into the burner.

SECTION 1: INTRODUCTION

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H2O BOILER HC SERIES IOM Manual

« Cet appareil doit être installé selon les

National Fuel Gas

Code d’installation du gaz natural et du

propane, CSA B149.1. »

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Figure 5: Main burner gas train

1.4.3 Gas Manifold and Control Assembly Tests

Safe operation and all performance criteria of all H2O BOILER products, incorporating the
installed gas manifold and control assembly, are proven before delivery when the products are
factory tested in accordance with the ANSI Z21.13- CSA 4.9- 2017 standards for Gas-fired hot
water boilers and ANSI Z21.10.3-2015-CSA 4.3-2015 for Gas-fired water heaters, circulating or
instantaneous.

1.4.4 Code Compliance

In Canada, boiler installation must conform to the requirements identified in the CGA Codes
CAN1-B149-1 or CAN1-B149-2 for gas burning appliances, CSA Codes B51 for boiler, pressure
vessel, and pressure piping, and/or all applicable local codes. All electrical connections are to be
made in accordance with the requirements of CSA C22.1, Canadian Electrical Code, Pat 1, and/or
all applicable local codes.

In the United States of America, the installation must conform to the requirements of the authority
having jurisdiction or, in the absence of such requirements, to the National Fuel Gas Code, ANSI
Z223.1-latest edition. All electrical wiring must be carried out in accordance with the National
Electrical Code ANSI/NFPA No.70-latest edition, and any additional state or local
code requirements. If an external power source is used, the unit must be electrically
grounded in accordance with the requirements of the authority having jurisdiction. In the
absence of such authority, the boiler must be electrically grounded in accordance with the
National Electrical Code ANSI/NFPA No. 70-latest edition.

The plumbing and condensate disposal must be carried out in accordance with the local plumbing
codes.

règlements locaux, ou en l’absence de tells règlements, selon le

Code, ANSI Z223.1/NFPA 54, ou les,

SECTION 1: INTRODUCTION

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WARNING:

Exceeding the maximum allowable gas manifold pressure could result
in over-firing of the unit and may cause permanent damage to the unit.

NOTES:

NOTES:

Boiler/water heater can be used in both closed loop and open loop (one

In the commonwealth of Massachusetts the installation shall be carried out
by a licensed gas fitter/plumber and comply with 48CMR

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 Air and gas flow rates are factory adjusted for optimum combustion

quality. Note that these settings may vary slightly at different site
conditions (calorific value of gas, duct length, elevation, etc.)

 After installation is completed, using a gas analyzer, the CO and O

contents of the exhaust gases should be re-checked to ensure their
compliance with those achieved at the factory and reflected in the test
report provided to your local H2O BOILER representative.

 IF adjustments to the factory settings of air and gas flows are made,

ensure that the manifold gas pressure does not exceed the pressure
specified on the boiler label.

2

1.5 Freeze Protection and Storage

In either an open or a closed loop configuration, the boiler must be isolated before draining. Due
to the radial geometry of the unit, it can only be drained by forced air method. The operator can

connect the forced air through the 3/8” air vent on the manifold and the drain connection on the

3/8” connection on the other manifold.

For short term storage, the operator can add antifreeze to protect the boiler against freezing
condition. In this case, the boiler or water heater does not need to be drained. The antifreeze must
be compatible with hydronic heating systems.

1.6 Water Treatment

All heat exchanger coils are constructed from high grade stainless steel. Therefore, high oxygen
content in the feed water should not result in any corrosion inside the coils. Since water flow
through coils is in turbulent mode, and they are continuously expanding and contracting; the
operation of the unit is to a large extent self-cleaning. Therefore, other potential minerals that may
exist in water should not have any adverse effect (on the tubes). However, if it is wished to supply
soft water to the boiler or water heater, then a sodium-based ion-exchanger may be used. Note that
“soft water” is defined as one having less than 0.12 British, or 0.17 US hardness level. Consult a
local water treatment consultant to determine if water treatment is required.



pass) operations.



SECTION 2: INSTALLATION

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SECTION 2: INSTALLATION

SECTION 2: INSTALLATION

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H2O BOILER HC SERIES IOM Manual

Warning:

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.

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2.1 Water Heater/ Boiler Package

Upon the receiving and unpacking of the equipment, check for any sign of damages, hit or dents.
Pay special attention to the gas train parts and safety devices installed. Verify total number of
pieces being shipped with the packing slip. All safety devices will be installed at the factory.

Each unit is supplied with:

 Burner/ Blower.
 Inlet and outlet manifolds.
 High temperature cut off switch with manual reset.
 Operating temperature controller.
 Pressure relief valve.
 Fully assembled gas train.
 One Temperature sensor installed on the outlet manifold
 Condensates drain kit.
 Flame sensor (inside burner).
 Flue gas connection.
 Pressure-Pressure/temperature gauge.
 All Safety features as described in Section 1.3.

Please contact H2O BOILER if items listed above are missing. Please be familiar with major
parts of the boiler before operating. Always exercise caution when transporting.
Instructions provided are only general guides, and are not substitute for common sense and sound
safe practices.

SECTION 2: INSTALLATION

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2.2 Removal of Existing Boiler

At the time of removal of an existing boiler, the following steps shall be followed with each
appliance remaining connected to the common venting system placed in operation, while the other
appliances remaining connected to the common venting system are not in operation.

 Seal any unused openings in the common venting system.
 Visually inspect the venting system for proper size and horizontal pitch and determine

there is no blockage or restriction, leakage, corrosion and other deficiencies which could
cause an unsafe condition.

 Insofar as is practical, close all building doors and windows and all doors between the

space in which the appliances remaining connected to the common venting system are
located and other spaces of the building. Turn on clothes dryers and any appliance 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. Close fireplace dampers.

 Place in operation the appliance being inspected. Follow the lighting instructions. Adjust

thermostat so appliance will operate continuously.

 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.

 After it has been determined that each appliance 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 appliance to their previous

condition of use.”

 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 the
Natural Gas and Propane Installation Code, CAN/CSA B149.1. 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 Chapter 13 of
the National Fuel Gas Code, ANSI Z223.1/NFPA 54, and/or the Natural Gas and
Propane Installation Code, CAN/CSA B149.1.

SECTION 2: INSTALLATION

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H2O BOILER HC SERIES IOM Manual

MODELS

TOP

FRONT

FLUE

BACK

L, SIDE

R, SIDE

FLOOR

ALL

40”

40”

1”

24”

24”

24”

Non-

Combustible

Note:

combustible material.

Note:

for burner removal and cleaning of the heat exchanger.

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2.3 Clearance from Combustible Material

Table 3: Clearances from combustible material

Refer to appliance rating plate for specified clearances for

Indicated clearances are minimum values; leave enough space

SECTION 2: INSTALLATION

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H2O BOILER HC SERIES IOM Manual

Notes:

For other than a direct vent appliance, the appliance must be located

The appliance should be located in an area where leakage of the tank
or connections will not result in damage to the area adjacent to the
appliance or to lower floors of the structure. When such locations
cannot be avoided, it is recommended that a suitable drain pan,
adequately drained, be installed under the appliance. The pan must

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2.4 Location

 Never install directly on carpet.



as close as practicable to a chimney or gas vent.



not restrict combustion air flow.

 This boiler/water heater is for indoor installation only.

 For service access to the Burner control box, condensate drain “U” trap, and gas train, refer

to the clearances indicated on the boiler/water heater rating plate. Note that some
jurisdictions may have their own clearance requirements. In such cases refer to all
applicable local codes.

 The boiler/water heater can be placed in a basement or utility room. It should not be placed

in an unconditioned area where the unit and condensation could be subject to freezing
temperatures.

 For reduced installation cost, locate the boiler/water heater as close to an outside wall as

possible.

 Flue gases can be vented out directly through a wall, or in case of retrofit installation, the

flue gas duct can be extended into the existing chimney.

 Keep boiler/water heater area clear and free from combustible materials, gasoline,

flammable vapors and liquids.

 Ensure that inlet to the blower is kept clear of any obstruction so that combustion air can

flow freely through to the air intake blower.

 A resilient pad to separate the boiler/water heater from floor when the appliance is installed

directly on carpeting, the appliance shall be installed on a metal or wood panel extending
beyond the full width and depth of the appliance by at least 3 in (76.2 mm) in any direction
or, if the appliance is installed in an alcove or closet, the entire floor shall be covered by the
panel. The panel must be strong enough to carry the weight of the heater when full of
water.

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Note:

If a water heater is installed in a closed water supply system, such as one
having a backflow preventer in the cold water supply line, means shall be
provided to control thermal expansion. Contact the water supplier or local

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2.5 Relief Valve piping

A pressure relief valve is supplied as standard equipment. The relief valve is extra protection
against damage that could be caused by excessive water pressure. Either, mal-functioning of
controls, or creation of steam pockets due to water stagnation in some parts of the coils, may cause
such excessive pressure. This latter condition could arise if one or both coils are not properly
purged.

The pressure relief valve should be connected to a suitable water drain. The drain pipe MUST
pitch down from the valve and its internal diameter should not be less than that of the relief valve.
The end of the drain line should not cause any restriction to the water flow, and should be
protected from freezing. There should not be any valve of any type installed between the pressure
relief valve and the end of the drain line. Similarly, there should not be any instrument installed
anywhere along the length of the drain valve, between the relief valve and the end of the drain line.
The relief valve is installed in vertical position and should remain in that position at all times.

2.6 Water Connection

plumbing inspector on how to control this situation.

All pre-installation work has been completed at the factory. Two water manifolds (inlet and outlet
headers) are provided with the unit.

Cold-water inlet and hot water outlet connections are clearly marked on the respective manifolds
of the boiler/water heater. The cold water supply line (in one pass applications), or return water (in
closed loop applications) should be connected to the cold water inlet of the unit. The hot water
supply line should be connected to the hot water outlet of the boiler. Both manifolds have 3”
stainless steel flange, ANSI 150 lbs inlet/outlet connections.

For further information on methods of connecting supply and return water piping to boilers/water
heaters consult available installation and piping guides developed according to local plumbing
codes.

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2.6.1 Potable water heater connection

In the case where water heater is being used for water (potable) heating and space heating:

 The piping and components connected to the water heater for the space heating application

shall be suitable for use with potable water.

 Toxic chemical, such as used for boiler treatment, shall not be introduced into the potable

water used for space heating.

 A water heater that will be used to supply potable water shall not be connected to any

heating system or component(s) previously used with a non-potable water heating
appliance.

 Water heaters for combination water/space heating cannot be used in space heating

application only.

2.6.2 Piping Arrangement

Typical flow arrangements for primary and secondary water piping are shown in Figures 6 – 10
below.

Single Boiler

Figure 6: Primary/Secondary Piping for Condensing Boilers (Single)

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Single Boiler w/ Storage Tank

Multiple Boilers

Figure 7: Primary/Secondary Piping for Condensing Boilers (Single with storage tank)

Figure 8: Primary/Secondary Piping for Condensing Boilers (Multiple)

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Variable Flow Arrangements (Primary Only)

Single Boiler

Multiple Boilers

Figure 9: Primary Only Variable Flow (Single)

Figure 10: Primary Only Variable Flow (Multiple)

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H2O BOILER HC SERIES IOM Manual

NOTE:

To ensure proper flow of condensate, it is recommended to install a “drain vent” of

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2.7 Condensate Line

Connect 3/4” ABS tubing from the condensate drain “U” trap, directly to the floor drain. Notice

that the line MUST be pitched downward towards the floor drain to avoid traps. DO NOT install

any valve of any type, or any other instrument between the condensate drain “U” trap and the end

of the condensate line.

approximately 1foot height at 0.5-1 foot downstream of the U trap.

2.8 Gas Line Connections

The installation must conform with one or more of the following, as applicable:

 Local codes or, in the absence of local codes, the National Fuel Gas Code, ANSI

Z223.1/NFPA 54 and/or CSA B149.1, Natural Gas and Propane Installation Code.

 The Manufactured Home Construction and Safety Standard, Title 24 CFR, Part 3280 and/

or CSA Z240 MH Series, Manufactured Homes.

 Local codes or, in the absence of local codes, Recreational Vehicles, NFPA 1192 and/or

CAN/CSA-Z240 RV Series.

Review the instructions below before any installation:

 The appliance and its individual shutoff valve must be disconnected from the gas supply

piping system during any pressure testing of that system at test pressures in excess of ½ psi
(3.5 kPa).

 The appliance must be isolated from the gas supply piping system by closing its individual

manual shutoff valve during any pressure testing of the gas supply piping system at test
pressures equal to or less than ½ psi (3.5 kPa).

 The appliance and its gas connection must be leak tested before placing the appliance in

operation.

 Install gas line for the appliance according to applicable codes.

The gas train comprises a pressure regulator, low gas pressure switch, solenoid valve, and the main
gas valve Figure 6. Gas pressure at the inlet to the pressure regulator should always remain in the
7” – 14” wc range. If higher pressures are present, consult the local gas company or gas installation
codes for installing the appropriate gas pressure regulator. Gas line from the meter to the
boiler/water heater should be of adequate size to prevent undue pressure drop. A manual shut off
valve should be installed in the gas line upstream of the pressure regulator, so that the control

SECTION 2: INSTALLATION

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NOTE:

Inlet gas pressure upstream of the unit must always remain within the 7” – 14” WC
range. The maximum inlet gas pressure must not exceed the value specified by the
manufacturer and that the minimum value listed is for the purposes of input

Warning:

Covering non-metallic vent pipe and fittings with thermal insulation is prohibited.

CAUTION:

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instruments (main gas valve, boiler/water heater gas regulator, and low gas pressure switch) could
be easily isolated and removed, whenever necessary. The valve should be clearly marked, located
outside the unit’s housing, readily visible and accessible for turning on and off. If the unit is to be
installed in, under, or directly attached to a pool, or spa, structure, the said manual valve should be
located outside the structure.

adjustment.

2.9 Electrical connection

If an external electrical source is utilized, the appliance, when installed, must be electrically
grounded in accordance with local codes or, in the absence of local codes, with the National
Electrical Code, ANSI/NFPA 70 and/or the CSA C22.1, Canadian Electrical Code, Part 1.

Label all wires prior to disconnection when servicing controls. Wiring errors can
cause improper and dangerous operation. Verify proper operation after servicing.

2.10 Vent Connection

For US and Canadian installations, vent termination must be in accordance and not less than those
specified in the current ANSI Z223.1/NFPA 54 National Fuel Gas Code or CSA B149.1, Natural
Gas and Propane Installation Codes, as applicable.

Use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel®
(polyphenylsulfone) in non-metallic venting systems is prohibited.

Provisions for adequate combustion and ventilation air in accordance with one of the following:

 The National Fuel Gas Code, ANSI Z223.1/NFPA 54 (Current Edition);
 CSA B149.1, Natural Gas and Propane Installation Code (Current Edition); or
 Applicable provisions of the local building code.

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H2O BOILER HC SERIES IOM Manual

Manufacturer

Vent Part Model

Material/Rigid Vent

Listed

Heat-Fab Inc.

Saf-T Vent System

Stainless Steel, (AL-29-4C), corrosion
resistance for use with Class II, III and IV
gas boilers – ANSI Z21.13

UL 1738 and ULC 636 Type
BH special gas vent

NovaFlex, Z­FLEX

Z-Vent

Stainless Steel, (AL-29-4C), corrosion
resistance for use with Class II, III and IV
gas boilers – ANSI Z21.13

UL 1738 and ULC 636 Type
BH special gas vent

DuraVent

FasNSeal

Stainless Steel, (AL-29-4C), corrosion
resistance for use with Class II, III and IV
gas boilers

UL 1738 and ULC 636 Type
BH special gas vent

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2.10.1 Suggested Single wall Vent system

It is recommended to install prefabricated factory-made vent parts each designed to be assembled
with the other without requiring field fabrication.

Table 4 Suggested Venting System

Refer to Guide line below for vent terminal termination

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Figure 11: Vent Terminal Termination

SECTION 2: INSTALLATION

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Canadian installation (note 1)

US installation (note 2)

A =

Clearance above grade,
veranda, porch, deck, or
balcony

12 in (30 cm)

12 in (30 cm) (Note 7)

B =

Clearance to window or door
that may opened

6 in (15 cm) for appliances ≤ 10,000
Btuh (3 kW), 12 in (30 cm) for

appliances > 10,000 Btuh (3 kW) and ≤

100,000 Btuh (30 kW), 36 in (91 cm)
for appliances > 100,000 Btuh (30 kW)

4 ft (1.2 m) below or to
side of opening; 1 ft
(300 mm) above
opening

C =

Clearance to permanently
close window

See note 4

See note 4

D =

Vertical clearance to
ventilated soffit located
above the terminal within a
horizontal distance of 2 ft
(61 cm) from the center line
of the terminal

See note 4

See note 4

E =

Clearance to unventilated
soffit

See note 4

See note 4

F =

clearance to outside corner

See note 4

See note 4

G =

Clearance to inside corner

See note 4

See note 4

H =

Clearance to each side of
center line extended above
meter/ regulator assembly

See note 4

See note 4

I =

Clearance to service
regulator vent outlet

Above a regulator within 3 ft (91 cm)
horizontally of the vertical center line
of the regulator vent outlet to a
maximum vertical distance of 15 ft
(4.5 m)

See note 4

J =

Clearance to non-mechanical
air supply inlet to building or
the combustion air inlet to
any other appliance

6 in (15 cm) for appliances ≤ 10,000

Btuh (3 kW), 12 in (30 cm) for

appliances > 10,000 Btuh (3 kW) and ≤

100,000 Btuh (30 kW), 36 in (91 cm)
for appliances > 100,000 Btuh (30 kW)

4 ft (1.2 m) below or to
side of opening; 1 ft
(300 mm) above
opening

K =

Clearance to a mechanical
air supply inlet

6 ft (1.83 m)

3 ft (91 cm) above if
within 10 ft (3 m)
horizontally

L =

clearance above paved
sidewalk or paved driveway
located on public property

7 ft (2.13) See note 5

7 ft (2.13 m)

M =

Clearance under veranda,
porch, deck, or balcony

12 in (30 cm) See note 6

See note 4

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Table 5: Vent Termination Guide Line

Notes:

1. In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code.

2. In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code.

3. For clearances not specified in ANSI Z223.1/ NFPA 54 or CSA-B149.1. Clearance in accordance with local installation
codes and the requirements of the gas supplier

4. “Clearance in accordance with local installation codes and the requirements of the gas supplier.”

5. A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family
dwellings and serves both dwellings.

6. Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.

7. Value is the minimum from the average snow line, refer to local codes for more specific requirements.

SECTION 2: INSTALLATION

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H2O BOILER HC SERIES IOM Manual

Fitting

Equivalent
Lengths

90 deg. Elbow

3’

45 deg. Elbow

2’

Condensate Tee

2’

Vent Cap

3’

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The vent for this appliance shall not terminate:

 Over public walkways; or
 Near soffit vents or crawl space vents or other areas where condensate or vapor could

create a nuisance or hazard or cause popery damage; or

 Where condensate vapor could cause damage or could be detrimental to the operation of

regulators, relief valves, or other equipment.

Vent termination should be in accordance with all applicable local codes. In addition, the
following conditions must be satisfied:

 Distances from adjacent public walkways, buildings, windows and building openings,

should be consistent with the National Fuel Gas Code, ANSI Z223.1.

 Minimum clearance of 4 feet (1.22 m) horizontally and in no case above or below, unless a

4-foot (1.22 m) horizontal distance is maintained from electric meters, gas meters,
regulators and relief equipment.

For other than a direct vent appliance,

 The appliance must be located as close as practicable to a chimney or gas vent.
 The appliance should be located in an area where leakage of the tank or connections will

not result in damage to the area adjacent to the appliance or to lower floors of the structure.

 When such locations cannot be avoided, it is recommended that a suitable drain pan,

adequately drained, be installed under the appliance. The pan must not restrict combustion
air flow.

 The duct should be corrosion resistant, air tight and short as possible. A condensate drain is

highly recommended for long duct or single wall vent. The condensate drain pipe should
pipe the condensate to appropriate drain. The combustion gases can be exhausted either
directly through the wall, or through a chimney (in case of retrofit applications). If venting
directly through a wall, allow at least a 5% rising slope of horizontal duct immediately after
the exhaust outlet on the boiler. Vent installation should be done by professional contractor
and in accordance to local building code and/or CSA B149.1 or ANSI Z223.1.

2.10.2 Vent Sizing

When determining the equivalent vent lengths, use the following table. Shown vent diameter in
Table 1 has been selected based on total of 100 feet equivalent length of air intake plus vent.

Table 6: Vent fittings equivalent length

SECTION 2: INSTALLATION

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H2O BOILER HC SERIES IOM Manual

NOTES:

The exhaust venting system must meet the requirements of type BH,

The exhaust duct outlet to the atmosphere MUST be wind protected by an

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

category II or IV boilers (i.e. corrosion resistant, water and air-tight).



approved wind cap.

Periodically inspect the vent duct for pin holes or cracks. Maintaining gas tight seal is very
necessary and important. Please apply appropriate condensate sealant (Mill-Pac) on these
openings.

2.11 General Instructions

 The boiler/water heater and its individual shutoff valve must be disconnected from the gas

supply piping system during any pressure testing of that system, at test pressures in excess of

0.5 psig. The unit must be isolated from the gas supply piping system by closing its individual

manual shutoff valve, during any pressure testing of the gas supply piping system at test
pressures equal or less that 0.5 psig.

 The boiler/water heater should be installed such that the gas ignition system components are

protected from water (dripping, spraying, rain, etc.) during appliance operation or service.

 The boiler/water heater and its gas connection must be leak tested, before placing the boiler in

operation.

 The boiler/water heater when installed must be electrically grounded and bonded in accordance

with the local codes or in the absence of such codes, in accordance with the National Electrical
Code, ANSI/NFPA 70.

 The boiler/water heater should be located in an area where leakage of the tank, or connections,

will not result in damage to the area adjacent to the appliance or to the structure. When such
locations cannot be avoided, it is recommended that a suitable drain pan, that drains adequately
be installed under the boiler. The pan must not restrict air- flow.

 The boiler should always be purged of natural gases before starting up. The operator should

also investigate and identify the cause of any trip before attempting to relight the boiler.

SECTION 2: INSTALLATION

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PAGE INTENTIONALLY LEFT BLANK

SECTION 3: OPERATION

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SECTION 3: OPERATION

SECTION 3: OPERATION

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WARNING:

Do not bypass any of the
instruments in the safety loop.
Doing so may cause serious

damage to the unit and its

surroundings.

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All units are factory assembled with Low Water Cut Off, ASME pressure relief valves (HV
stamp), pressure gauges, high temperature limit cut off, gas pressure switch, air pressure switch,
drain valves and vent valves. Flame sensors provided are either flame rod or UV sensor.

In addition to standard controls and safety devices provided with the boiler, compliance with
ASME CSD.1, IRI and FM codes and requirements are available.

3.1 Sequence of Operation

3.1.1 Safety Loop

A) Components

Referring to section 1.3, for a description, and Figure 13, Control System Schematic, the safety
loop includes the following components:

 High temperature cut off switch

 Operating temperature switch

 Low water cut off switch

 Low gas pressure switch

 Air Pressure Switches

 Flow Switch

B) Remote Enable/Disable

Every boiler/water heater is fully tested at the factory prior to shipment. When the unit is

tested at the factory, a “jumper” is placed between terminals identified as “Remote

Enable/Disable” (see Figure 13). If BMS is used, this jumper should be replaced by wires
from the BMS. In the absence of a BMS, the operation of the unit is governed by the
Siemens temperature controller.

3.1.2 Pre-Purge

 Once the blower starts operating, the air pressure switch will close. This switch has

been factory adjusted such that when the blower reaches its minimum frequency it
will close.

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 When the air pressure switch is closed and safety loop is satisfied, pre-purge will

start.

 Blower continues to run at its maximum frequency for a period identified as the

purge time.

3.1.3 Pilot Flame

 After completion of the pre-purge period, the burner controller sends the required

voltage to the ignition rod, and 120V to the two, pilot safety shut off valves. The
valves open simultaneously with the activation of the ignition rod. Upon pilot
ignition, and after the flame is detected by the sensor, the ignition rod will be
deactivated.

 If after 5 seconds activation of the flame rod and opening of the gas valves, pilot

flame is not established and detected by the flame sensor, the gas valves will
immediately shut down and the boiler/water heater goes into the “lock-out” mode.
The unit will not re-start until the burner controller is manually reset.

3.1.4 Main Flame

 Once pilot flame is established burner controller will send 120V to the two main

safety shut off valves. From these valves, gas flows into the gas butterfly valve.

 Air supplied by the blower flows through to the burner head where it mixes with

gas and the air/gas mixture is ignited.

 The pilot safety shut of valves will open five seconds after the main safety valves

are closed. If at any time during the operation flame (pilot or main) is not detected
the boiler/water heater will immediately shut down and will not restart until the
burner controller is manually reset.

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NOTE:

If as a result of mal-functioning of the temperature controller the
discharge water temperature increases above that of the high limit
temperature switch, the unit will automatically shut down and will not
re-start until said switch is manually re-set.

WARNING:

over-firing of the unit and may cause permanent damage to the unit.

NOTES:

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 Air and gas flow rates are factory adjusted for optimum combustion

quality. Note that these settings may vary slightly at different site
conditions (calorific value of gas, duct length, etc.).

 After installation is completed, using a gas analyzer, the CO and O

contents of the exhaust gases should be re-checked to ensure their
compliance with those achieved at the factory and reflected in the test
report provided to your local H2O Boiler representative.

 IF adjustments to the factory settings of air and gas flows are made,

ensure that the manifold gas pressure does not exceed the pressure
specified on the boiler label.

Exceeding the maximum allowable gas manifold pressure could result in

2

3.1.5 Continuous Operation

The unit continues to operate at low fire for as long as the outlet (discharge) temperature remains
higher than the desired temperature- with respect to the differentials -, and lower than the
maximum operating temperature; both being set on the temperature controller. The temperature
sensor installed on the outlet manifold continuously measures the discharge water temperature.
Signals from this sensor are sent to the temperature controller. As soon as the discharge water
reaches the desired temperature (set on the controller by the owner), the process is reversed and the
input is decreased so that discharge water remains at constant temperature. This throttle (load
tracking) process continuously takes place through increase or decrease in the air/gas mixture
(opening/closing of the butterfly valve and air damper), thereby ensuring water is always supplied
at  1 C of the desired operating (discharge) temperature.

If the outlet water temperature reaches the maximum operating temperature, the boiler/water heater
will shut down and goes into the standby mode. The unit will automatically re-start when the
water temperature drops below the operating set point minus the differential temperature.

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NOTE:

technician.

WARNING:

the boiler/water heater

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3.2 PRE-COMMISSIONING

Water connections (Return and Supply Lines)

 Purge air from the piping system, and from the boiler/water heater. To purge the unit, run

water through the open coils for at least 5 minutes. The coils are now completely purged.

Gas Connections

 All pipe connections should be carried out in strict compliance with all applicable local

codes.

 Selection of the gas regulator model and size should be carried out in accordance with the

design requirements.

 Conduct a complete leak test on the unit’s gas train, and associated components.

 Measure the static pressure upstream of the unit to ensure it is within the prescribed range

of 7” - 14” wc.

Vent Connection

 Installation must be carried out in accordance to all applicable local codes and factory

guidelines.

 When required, a proper drain should be installed on the vent.

Condensate Line Connection

 Inspect the condensate line and ensure it is installed in accordance with the factory

guidelines.

Power Connection

 Inspect all wiring connections to the unit and ensure they comply with all applicable local

codes.

 Ensure that the appropriate power supply has been connected to the unit (please refer to the

electrical rating on the unit’s nameplate).

 Ensure the temporary jumpers have been removed from the unit’s control panel.

 If applicable, ensure the external control connections have been wired.

Start-up and commissioning MUST be carried out by a GMI qualified

Ensure the manual gas valve is closed prior to power being supplied to

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WARNING:

the unit’s nameplate.

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3.3 Commissioning

 Purge heat exchanger coils in accordance with the procedure outlined in paragraph I of

section 3.2.

 Measure and meter the flow rate through the unit to be at least at the minimum of flow

rates indicated in Table 1.

 Connect (plug in) the power supply to the proper outlet. Turn the “ON/OFF” switch to the

“ON” position.

 After the system has undergone the sequence of events described in Section 3.1 above and

when the two safety shut off valves in the main gas line are opened, the unit will be in
regular operating mode.

 The Dungs air pressure switch installed on the side of the burner/ blower has been factory

set at 0.3” wc.

 The boiler should be purged of any combustible gases before starting.

 Test Points

o Measure gas line pressure upstream of the gas pressure regulator to ensure it is

within the specified range of 7” – 14” wc.

o Measure the gas manifold pressure at the test point located adjacent to the

burner’s gas inlet connection port; ensure it is within the specified range on the
burner label.

The gas manifold pressure should not exceed the maximum value shown on

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HC

Model

Temperature Difference (°F)

20

30

40

50

60

70

80

90

100

110

120

130

600

Flow (GPM)

43

29

21

17

14

12

11

10 9 Press. Drop (PSI)

1

0.5

0.3

0.2

0.2

0.1

0.1

0.1

0.1

1000

Flow (GPM)

71

47

36

29

24

20

18

16

14

Press. Drop (PSI)

1

0.5

0.3

0.2

0.2

0.1

0.1

0.1

0.1

1500

Flow (GPM)

107

71

53

43

36

31

27

24

21

20

Press. Drop (PSI)

1

0.4

0.3

0.2

0.1

0.1

0.1

0.1

0.1

0.1

2000

Flow (GPM)

143

95

71

57

47

41

36

32

29

26

24

Press. Drop (PSI)

1.1

0.6

0.3

0.2

0.2

0.1

0.1

0.1

0.1

0.1

0.1

2500

Flow (GPM)

178

119

89

71

59

51

45

40

36

32

30

27

Press. Drop (PSI)

1.3 1 0.4

0.3

0.2

0.1

0.1

0.1

0.1

0.1

0.1

0.1

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3.4 Boiler Capacity and recovery rate

Determining What Boiler Capacity You Need

To determine the correct H2O BOILER for your application, follow these simple steps:

 Locate the temperature difference (∆T) required by your system at the top of the table.
 Moving down the chart, select the GPM flow rate closest to that you require.
 From that point, select the boilers appropriate for your chart position from the column on

the left.

 The pressure drop (PSI) is also shown in Table 7 based on the selected flow rate.

Note: This chart provides approximate values for estimation purposes; conditional safety factors
and application specifics may affect boiler requirements.

Table 7: HC Series boiler capacity selection (safety factor of 25% already included)

Figure 12: HC Series Water Pressure Drop

SECTION 3: OPERATION

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SECTION 4: MAINTENANCE

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H2O BOILER HC SERIES IOM Manual

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SECTION 4: MAINTENANCE

SECTION 4: MAINTENANCE

34

H2O BOILER HC SERIES IOM Manual

Monthly

 Check unit gas piping
 Check unit ventilation stack
 Check unit air piping (if applicable)
 Check unit pressure relief valves
 Check unit condensate drain system

Every six months

 Use a combustion analyser to check combustion performance

Annually or end of
heating season

 Shutdown the unit
 Perform annual maintenance procedure
 Perform commissioning start-up (for year round usage)

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The H2O BOILER HC Series units require the following maintenance duties performed to ensure
long and problem free service life. Failure to perform the maintenance duties described in this
manual and unit component literature may result in severe damage to the unit and/or the
mechanical system.

4.1 Maintenance Schedule

The unit owner and/or operator is required to follow the maintenance schedule below.

4.2 General Procedure

The following maintenance procedure is required to be performed annually and prior to every cold
unit start.

 Address existing problems

o Address any existing problems reported by the owner, building operator and resolve before

proceeding with the maintenance service.

 Inspect mechanical room

o Before proceeding work on the unit, remove all combustible or flammable materials within

the minimum clearances to combustibles.

o Clean up the unit area. If the unit draws combustion air directly from the mechanical room,

remove any unnecessary items that may obstruct or contaminate combustion air.

 Inspect Boiler Casing

o Inspect the sheet metal covering the insulation for any sign of rust or corrosion. If

necessary, contact your service person to clean the sheet metal panels.

SECTION 4: MAINTENANCE

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H2O BOILER HC SERIES IOM Manual

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 Clean up condensate drain

o Inspect the condensate drain system including the drain line, vent line, fittings and

condensate trap.

o Ensure there are no restrictions.

 Inspect all piping

o Inspect all gas and water piping and check for leaks.
o Fix the leaks if found.

 Inspect ventilation system

o Inspect the entire ventilation system for air and flue gas. Check for obstruction, corrosion

and leakage. Fix any leakages on fittings or from corrosion.

o Check the duct and draft hood to ensure there is no restrictions or signs of rust.
o Inspect all flue gas passageways, including the inner surface of the heat exchanger for any

sign of rust or corrosion.

 Inspect pressure relief valve

 Inspect burner system (IMPORTANT – Dual Fuel Option)

o Remove the top cover by undoing the fasteners securing the cover.
o Remove the burner pilot, UV flame sensor and the flame observation port.
o Check for calcification on the surfaces of the pilot and flame sensor.
o Clean the glass on the flame observation port.
o Replace the components if determined unserviceable.
o Check for any piping/orifice blockages.
o Inspect the central plate and the burner for any sign of damage or corrosion.

 Inspect electronic wiring

o Inspect the unit wiring and ensure the leads are securely attached and free of deterioration.

 Inspect control settings

o Check the unit settings are matching the operator’s requirements.
o Any other unit components may have user-specific settings as well. Inspect the settings and

maintain consistency (if applicable).

 Initiate unit start-up

o Follow the instructions in Section 3: Operation, start the unit.
o Continuously monitor unit operating temperature and pressure as the post start-up

maintenance duties are performed.

SECTION 4: MAINTENANCE

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H2O BOILER HC SERIES IOM Manual

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4.3 Service Notes

 H2O BOILER boilers and water heaters have been designed and developed based on a

unique patented technology. When operated properly, the products will provide the owner
with years of trouble free performance. To benefit for many years, from the unique
performance characteristics of these boilers and water heaters, it is recommended to have
your
boiler/water heater inspected by a qualified service person at least once every year.

 Ensure that air intake and exhaust ducts are always free of any debris and restrictions. This

will allow the electric motor to operate under normal loads, as well as allowing for a clean
combustion process. Do not store anything against the boiler and ensure that the boiler is
kept in a clean environment. Do not store any combustible material, flammable liquid, or
vapor, in the vicinity of the boiler.

 Should overheating occur or the gas supply fails to shut off, turn off the manual gas control

valve.

 Label all wires prior to disconnection when servicing the controls. Wiring errors can cause

improper and dangerous operation.

 Verify proper operation after each service (refer to the start-up report).

SECTION 4: MAINTENANCE

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H2O BOILER HC SERIES IOM Manual

Fault

Cause

Corrective Action

 Blower does not start

 Power not supplied to the unit.

 Safety loop open.

 None of the above

 Ensure power switch is on.
 Check both fuses on the power and the supply

sides.

 Ensure BMS (if connected) calls for heat.
 Ensure high temperature limit switch is closed.
 Ensure operating temperature switch is closed.
 Ensure low gas pressure switch are closed.

 See burner catalogue for burner controller

trouble shooting.

 Unit does not start

 Blower does not run.

 Air pressure switch installed

on the housing is open.

 Gas pressure switch is open.

 No ignition.

 See above

 Adjust switch.
 Replace switch (if defective).

 Adjust the switch.
 Replace switch (if defective).

 See burner catalogue for burner controller

trouble shooting

 Pilot flame failure

 Pilot gas valve not opened

 No ignition

 Check the electrical connections to ensure they

are all securely connected (see the schematic
wiring diagram for terminals).

 Check the two safety shut off valves. Replace if

defective.

 Check the electrical connections to ensure they

are all securely connected (see burner catalogue)

for terminals.
Measure gas pressure and air pressure in the pilot
burner at the available test port. Ensure it is within
the specified 2”-5” wc. If pressure is not available
check both safety shut off valves and the pressure
regulator. Replace any defective component, if
necessary.

 Main flame failure

 Main gas valve not opened.

 Insufficient gas pressure

 Check the electrical connections to ensure they

are all securely connected.
 Check the two, safety shut off valves. Replace

if defective.

 Check gas pressure at the inlet test port of the

first safety shut off valve. It should be within

the specified 7-14” wc range. Adjust the

pressure regulator to obtain the required

pressure. If problem persists, replace the valve.

Repeat process for the second safety shut off

valve.

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4.2 Troubleshooting

SECTION 4: MAINTENANCE

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H2O BOILER HC SERIES IOM Manual

 Unit out of adjustment

 Insufficient draft

 Check the gas manifold pressure to ensure it

complies with the value given in the factory test

report. If required, re-adjust the boiler/water (see

factory test report for the adjustment values).

 Check the vent system to ensure it is not

clogged.

 Unit fails at frequent

intervals (excessive

cycling)

 Operating temperature is set

too low.

 Break in controls wiring.

 Unit is over-sized

 Check the setting on operating temperature

switch to ensure it is set at desire temperature.
 If applicable, check the differential adjustment

on the operating temperature switch.

 Check all connections to and from the wiring

block located immediately below the blower.

 Check the maximum heat requirement with the

engineer and ensure the unit is of the appropriate

size.

 Unclean combustion

 Insufficient air in the

mechanical room

 Unit out of adjustment

 Check all the louvers and air openings in the

mechanical room to ensure they are free of any

obstructions and there is sufficient inflow of

fresh air into the room.

 Using a gas analyzer re-adjust the air and gas

settings.

 Air bubble sound in

the unit.

 Poor water circulation in one

or both coils

 Foreign material in one or

both coils.

 Steam pockets in one or both

coils.

 Completely purge each coil.

 Drain each coil with pressurized air and re-

purge.

 Check water flow rate to ensure it complies with

the required minimum flow rate.

 Gas Odor

 Leak in piping.

 Exhaust gas leakage

 Using a gas detector, check all the connections

(inlet and outlet) of all instruments on the gas

line. Repair as required.

 Check the vent system to ensure there are no

cracks or other openings (holes cut for insertion

of thermocouples during the start-up). Repair if

required.

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Technical Data

39

H2O BOILER HC SERIES IOM Manual

Figure 13: Control system schematic

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Technical Data

Control System Schematic

Technical Data

40

H2O BOILER HC SERIES IOM Manual

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Technical Data

41

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Reports

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https://dvachvac.com/commercial-boilers