PB MI85 Series Installation, Operation & Maintenance Manual

MI85

™

Boilers

Series

Gas

Installation,
Operation &
Maintenance
Manual

USING THIS MANUAL 1

A. INSTALLATION SEQUENCE . . . . . . . . . . . . .1

B. SPECIAL ATTENTION BOXES . . . . . . . . . . . .1

1. PREINSTALLATION 2

A. ACCESSIBILITY CLEARANCES . . . . . . . . . . .2

B. CLEARANCE FROM COMBUSTIBLE

CONSTRUCTION . . . . . . . . . . . . . . . . . . . . . .2

C. AIR FOR COMBUSTION AND

VENTILATION . . . . . . . . . . . . . . . . . . . . . . . . .2

D. INSTALLATION SURVEY . . . . . . . . . . . . . . . .5

E. PLANNING THE LAYOUT . . . . . . . . . . . . . . . .5

2. BOILER SET-UP 6

3. WATER PIPING AND CONTROLS 7

A. BOILER SUPPLY AND RETURN . . . . . . . . . . .7

B. SAFETY RELIEF VALVE . . . . . . . . . . . . . . . . .8

C. PIPING FOR ZONED SYSTEMS . . . . . . . . . .9

D. EXPANSION TANK . . . . . . . . . . . . . . . . . . . .10

E. INDIRECT-FIRED WATER HEATER . . . . . . .10

F. FREEZE PROTECTION . . . . . . . . . . . . . . . . .10

4. VENTING 11

A. VENT PIPING AND CHIMNEY . . . . . . . . . . .11

B. INTEGRAL DRAFT HOOD . . . . . . . . . . . . . .11

C. VENT DAMPER INSTALLATION –

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . .11

D. BOILER REMOVAL FROM COMMON

VENTING SYSTEM . . . . . . . . . . . . . . . . . . .13

5. GAS PIPING 14

6. ELECTRICAL 16

A. WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

B. ZONED SYSTEM WIRING . . . . . . . . . . . . . .16

C. CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . .16

D. SEQUENCE OF OPERATION . . . . . . . . . . . .19

7. START-UP PROCEDURES 21

A. COMPLETING THE INSTALLATION . . . . . .21

B. CONTROL DESCRIPTIONS . . . . . . . . . . . . .24

C. ADJUSTMENT OF GAS PRESSURE

REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . .24

D. CHECKING BURNER INPUT . . . . . . . . . . . . .24

E. CHECK-OUT PROCEDURE . . . . . . . . . . . . . .25

8. TROUBLESHOOTING 26

A. SHUT-DOWN CAUSED BY PILOT OUTAGE,

BLOCKED VENT SHUT-OFF SWITCH OR

FLAME ROLL-OUT SAFETY SHUT-OFF

SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

B. TROUBLESHOOTING GUIDES . . . . . . . . . .26

9. MAINTENANCE 29

A. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . .30

B. DAILY (WITH BOILER IN USE) . . . . . . . . . . .30

C. WEEKLY (WITH BOILER IN USE) . . . . . . . . .30

D. MONTHLY (WITH BOILER IN USE) . . . . . . .30

E. ANNUALLY (BEFORE START OF HEATING

SEASON) . . . . . . . . . . . . . . . . . . . . . . . . . . .30

10. BOILER DIMENSIONS & RATINGS 32

11. REPAIR PARTS 33

A. BASE/COMBUSTIBLE FLOOR PAN . . . . . . .33

B. MANIFOLD, GAS VALVE & PILOT . . . . . . . .34

C. BLOCK/DRAFT HOOD & JACKET . . . . . . . .36

D. CONTROLS/CIRCULATOR/VENT

DAMPER & CONVERSION KITS . . . . . . . . .38

TABLE OF CONTENTS

TABLE OF CONTENTS

1

A. INSTALLATION SEQUENCE

Follow the installation instructions provided in this
manual in the order shown. The order of these
instructions has been set in order to provide the installer
with a logical sequence of steps that will minimize
potential interferences and maximize safety during
boiler installation.

B. SPECIAL ATTENTION BOXES

Throughout this manual you will see special attention
boxes intended to supplement the instructions and make
special notice of potential hazards. These categories
mean, in the judgment of PB Heat, LLC.:

Indicates special attention is needed, but not directly
related to potential personal injury or property
damage.

NOTICE

Indicates a condition or hazard which will or can
cause minor personal injury or property damage.

CAUTION

DANGER

Indicates a condition or hazard which will cause
severe personal injury, death or major property
damage.

USING THIS MANUAL

USING THIS MANUAL

Indicates a condition or hazard which may cause
severe personal injury, death or major property
damage.

WARNING

2

A. ACCESSIBILITY CLEARANCES

Install boiler not less than 24″ (610 mm) between the
left side, top, and front of the boiler and adjacent wall or
other appliance, when access is required for servicing.

B. CLEARANCE FROM COMBUSTIBLE

CONSTRUCTION

The design of this boiler is certified for alcove installation
with the following clearances:

1. 6″ (152 mm) between sides and combustible

construction.

2. 24″ (610 mm) between top of jacket and

combustible construction.

3. 6″ (152 mm) between draft hood and combustible

construction.

4. 6″ (152 mm) between vent pipe and combustible

construction.

5. 10″ (254 mm) between rear of jacket and

combustible construction.

C. AIR FOR COMBUSTION AND

VENTILATION

1. Adequate combustion air and ventilation air must be
provided for this appliance in accordance with the
section of the National Fuel Gas Code entitled, “Air
for Combustion and Ventilation” or applicable
provisions of the local building code. Subsections 2
through 8 as follows are based on the National Fuel
Gas Code requirements.

2. Required Combustion Air Volume:

The total required
volume of indoor air is to be the sum of the required
volumes for all appliances located within the space.
Rooms communicating directly with the space in
which the appliances are installed and through
combustion air openings sized as indicated in
Subsection 3 are considered part of the required
volume. The required volume of indoor air is to be
determined by one of two methods.

a. Standard Method: The minimum required

volume of indoor air (room volume) shall be 50
cubic feet per 1000 BTU/Hr (4.8 m

3

/kW). This
method is to be used if the air infiltration rate is
unknown or if the rate of air infiltration is known
to be greater than 0.6 air changes per hour. As
an option, this method may be used if the air
infiltration rate is known to be between 0.6 and

0.4 air changes per hour. If the air infiltration rate
is known to be below 0.4 then the Known Air
Infiltration Rate Method must be used. If the
building in which this appliance is to be installed
is unusually tight, PB Heat recommends that the
air infiltration rate be determined.

b. Known Air Infiltration Rate Method: Where

the air infiltration rate of a structure is known,
the minimum required volume of indoor air for
appliances other than fan assisted and for the
Series MI™ Boiler shall be determined as follows:

PREINSTALLATION

1. PREINSTALLATION

Read carefully, study these instructions before beginning work.

This boiler must be installed by a qualified contractor.

The boiler warranty can be voided if the boiler is not installed, maintained and serviced correctly.

The equipment must be installed in accordance with those installation requirements of the authority having
jurisdiction or, in the absence of such requirements, to the current edition of the

National Fuel Gas Code

, ANSI

Z223.1/NFPA 54 and/or CAN/CSA B149.1,

Natural Gas and Propane Installation Code

.

Where required by the authority having jurisdiction, the installation must conform to

American Society of

Mechanical Engineers Safety Code for Controls and Safety Devices for Automatically Fired Boilers,

ASME CSD-1.

NOTICE

Do not install this boiler on carpeting. Boiler
installation on carpeting is a fire hazard. Install this
boiler on non-combustible flooring or use a
combustible floor pan to install this boiler on other
non-carpeted flooring.

WARNING

Do not install this boiler on combustible flooring
unless it is installed on a special combustible floor
pan provided by PB Heat, LLC. Boiler installation on
combustible flooring without the special pan is a fire
hazard.

To order combustible floor pan, use the 5-digit stock
codes listed in Table 11.1 of this manual.

WARNING

21 ft

3

I

other

ACH 1000

Btu

/

hr

Required Volume

other

=

⎛
⎜
⎝

⎛

⎜

⎝

3

where:

I

other

= Input of appliances other than fan

assisted in Btu/hr

ACH = air change per hour (percent of the

volume of the space exchanged per
hour, expressed as a decimal)

For fan assisted appliances, calculate the required
volume of air using the following equation:

I

fan

= Input of the fan assisted appliances in

Btu/hr

Note: These calculations are not to be used for
infiltration rates greater than 0.60 ACH.

3. Indoor Air Opening Size and Location:

Openings
connecting indoor spaces shall be sized and located
as follows:

a. Combining spaces on the same floor:

Provide two permanent openings communicating
with additional spaces that have a minimum free
area of 1 in

2

per 1000 Btu/hr (22 cm2per 1000 W)
of the total input rating of all gas fired equipment
but not less than 100 in

2

(645 cm2). One
opening is to begin within 12 inches (305 mm)
from the top of the space and the other is to
begin within 12 inches (305 mm) from the floor.
The minimum dimension of either of these
openings shall be 3 inches (76 mm). See Figure

1.1 for an illustration of this arrangement.

b. Combining spaces on different floors:

Provide one or more permanent openings
communicating with additional spaces that have
a total minimum free area of 2 in

2

per 1000

Btu/hr (44 cm

2

per 1000 W) of total input rating
of all equipment. See Figure 1.2 for an
illustration of this arrangement.

4. Outdoor Combustion Air:

Outdoor combustion air is
to be provided through one or two permanent
openings. The minimum dimension of these air
openings is 3 inches (76 mm).

a. Two Permanent Opening Method: Provide

two permanent openings. One opening is to
begin within 12 inches (305 mm) of the top of
the space and the other is to begin within 12
inches (305 mm) of the floor. The openings are
to communicate directly or by ducts with the
outdoors or with spaces that freely communicate
with the outdoors. The size of the openings shall
be determined as follows:

i. Where communicating directly or through

vertical ducts with the outdoors each opening
shall have a minimum free area of 1 in

2

per

4000 Btu/hr (22 cm

2

per 4000 W) of total
input rating for all equipment in the space.
See Figure 1.3 for openings directly
communicating with the outdoors or Figure

1.4 for openings connected by ducts to the
outdoors.

PREINSTALLATION

15 ft

3

I

fan

ACH 1000

Btu

/

hr

Required Volume

fan

=

⎛
⎜
⎝

⎛

⎜

⎝

Figure 1.1: Air Openings – All Air from Indoors

on the Same Floor

Figure 1.2: Air Openings – All Air from Indoors

on Different Floors

Figure 1.3: Air Openings – All Air Directly from

Outdoors

4

ii. Where communicating with the outdoors

through horizontal ducts, each opening shall
have a minimum free area of 1 in

2

per 2000

Btu/hr (22 cm

2

per 2000 W) of total rated
input for all appliances in the space. See
Figure 1.5.

b. One Permanent Opening Method: Provide

one permanent opening beginning within 12
inches (305 mm) of the top of the space. The
opening shall communicate directly with the
outdoors, communicate through a vertical or
horizontal duct, or communicate with a space
that freely communicates with the outdoors. The
opening shall have a minimum free area of 1 in

2

per 3000 Btu/hr of total rated input for all
appliances in the space and not less than the
sum of the cross-sectional areas of all vent
connectors in the space. The gas-fired equipment
shall have clearances of at least 1 inch (25 mm)
from the sides and back and 6 inches (150 mm)
from the front of the appliance. See Figure 1.6
for this arrangement.

5. Combination Indoor and Outdoor Combustion Air:
If the required volume of indoor air exceeds the
available indoor air volume, outdoor air openings or
ducts may be used to supplement the available
indoor air provided:

a. The size and location of the indoor openings

comply with Subsection 3.

b. The outdoor openings are to be located in

accordance with Subsection 4.

c. The size of the outdoor openings are to be sized

as follows:

where:

A

req

= minimum area of outdoor openings.

A

full

= full size of outdoor openings calculated

in accordance with Subsection 4.

V

avail

= available indoor air volume

V

req

= required indoor air volume

6. Engineered Installations:

Engineered combustion air
installations shall provide an adequate supply of
combustion, ventilation, and dilution air and shall be
approved by the authority having jurisdiction.

7. Mechanical Combustion Air Supply:

a. In installations where all combustion air is

provided by a mechanical air supply system, the
combustion air shall be supplied from the
outdoors at the minimum rate of 0.35 ft

3

/min per
1000 Btu/hr (0.034 m3/min per 1000 W) of the
total rated input of all appliances in the space.

b. In installations where exhaust fans are installed,

additional air shall be provided to replace the
exhaust air.

PREINSTALLATION

Figure 1.4: Air Openings – All Air from Outdoors

through Vertical Ducts

Figure 1.5: Air Openings – All Air from Outdoors

through Horizontal Ducts

Figure 1.6: Air Openings – All Air from Outdoors

through One Opening

V

avail

1 –

V

req

A

req

= A

full

x

⎛
⎜
⎝

⎛

⎜

⎝

5

c. Each of the appliances served shall be

interlocked to the mechanical air supply to
prevent main burner operation when the
mechanical air supply system is not in operation.

d. In buildings where the combustion air is provided

by the mechanical ventilation system, the system
shall provide the specified combustion air rate in
addition to the required ventilation air.

8. Louvers & Grills:

a. The required size of openings for combustion,

ventilation, and dilution air shall be based on the
net free area of each opening.

i. Where the free area through a louver or grille

is known, it shall be used in calculating the
opening size required to provide the free area
specified.

ii. Where the free area through a louver or grille

is not known, it shall be assumed that wooden
louvers will have 25% free area and metal
louvers and grilles will have 75% free area.

iii. Nonmotorized dampers shall be fixed in the

open position.

b. Motorized dampers shall be interlocked with the

equipment so that they are proven in the full
open position prior to ignition and during
operation of the main burner.

i. The interlock shall prevent the main burner

from igniting if the damper fails to open
during burner startup.

ii. The interlock shall shut down the burner if

the damper closes during burner operation.

9. Combustion Air Ducts

a. Ducts shall be constructed of galvanized steel or

an equivalent corrosion- resistant material.

b. Ducts shall terminate in an unobstructed space,

allowing free movement of combustion air to the
appliances.

c. Ducts shall serve a single space.

d. Ducts shall not serve both upper and lower

combustion air openings where both such
openings are used. The separation between ducts
serving upper and lower combustion air
openings shall be maintained to the source of
combustion air.

e. Ducts shall not be screened where terminating in

an attic space.

f. Horizontal upper combustion air ducts shall not

slope downward toward the source of the
combustion air.

g. The remaining space surrounding a chimney

liner, gas vent, special gas vent, or plastic piping
installed within a masonry, metal, or factory built
chimney shall not be used to supply combustion
air.

h. Combustion air intake openings located on the

exterior of buildings shall have the lowest side of
the combustion air intake opening at least 12
inches (305 mm) above grade.

D. INSTALLATION SURVEY

For new and existing installations, a Water Installation
Survey is available from PB Heat, LLC. The survey will
provide information on how a hot water boiler works
with your specific system and will provide an overview
of hot water system operation in general.

You can also use this survey to locate system problems
which will have to be corrected. To obtain copies of the
Water Installation Survey, contact your PB Heat
representative or download it from PeerlessBoilers.com.

E. PLANNING THE LAYOUT

Prepare sketches and notes of the layout to minimize the
possibility of interferences with new or existing
equipment, piping, venting and wiring.

Liquefied Petroleum (LP) is heavier than air and may
collect or “pool” in a low area in the event of a leak
from defective equipment. This gas may then ignite,
resulting in a fire or explosion.

WARNING

PREINSTALLATION

6

BOILER SET-UP

1. Provide a sound, level foundation. Locate boiler as
near to the chimney or outside wall as possible and
centralized with respect to the heating system.

2. Locate boiler in front of installation position before
removing crate.

3. If using combustible floor pan, position pan on
foundation or flooring.

4. Separate the wood shipping pallet from the boiler
base by removing two (2) hold-down bolts at each
end of the boiler base.

5. Move boiler into final position. If using combustible
floor pan, install boiler on pan as outlined in the
instructions included with the pan.

2. BOILER SET-UP

7

A. BOILER SUPPLY AND RETURN

1. Size the supply and return to suit the system. A
typical piping arrangement is shown in Figure 3.1.
Refer also to the I=B=R Guide - Residential
Hydronic Heating Installation/Design and the PB
Heat Water Survey for additional guidance during
water piping installation.

2. Return Piping:
Pipe the drain valve to a tee, provided, and the
1-1/4 NPT return tapping near the bottom of the left
section. Pipe the return to the tee. Pipe the drain
valve nipples and tee to the 1-1/4 NPT return
tapping as shown in Figure 3.1.

3. Supply Piping:
Pipe the supply to the 1-1/2 NPT supply tapping at
the top and rear of the boiler.

4. When system return water temperature will be below
130°F (54°C), pipe the boiler with a bypass
arrangement to blend the system return and hot
supply to obtain at least 130°F (54°C) entering the
boiler. For more information on bypass piping,
consult the PB Heat Water Survey.

3. WATER PIPING AND CONTROLS

Figure 3.1: Supply and Return Piping

WATER PIPING AND CONTROLS

8

5. Install this boiler so that the gas ignition system
components are protected from water (dripping,
spraying, etc.) during appliance operation and
service (circulator replacement, condensate trap,
control replacements, etc.).

6. If this boiler and distribution system is used in
conjunction with a refrigeration system, pipe the
chilled medium in parallel with the boiler and install
the proper valve to prevent the chilled medium from
entering the boiler. A drawing illustrating this hook­up is provided in Figure 3.2.

7. When the boiler is connected to heating coils
located in air handling units where they may be
exposed to refrigerated air circulation, install flow
control valves or other automatic means to prevent
gravity circulation of the boiler water during the
cooling cycle.

8. If this boiler is installed above radiation level,
provide a low water cutoff device, either as a part of
the boiler or at the time of boiler installation.

B. SAFETY RELIEF VALVE

1. Locate safety relief valve and fittings in bag
assembly.

2. If air elimination is not required at the safety relief
valve tapping, install valve and piping as shown in
Figure 3.3.

3. For air elimination at the safety relief valve tapping,
install valve and piping as shown in Figure 3.4.

Pipe the discharge of safety relief valve to prevent
injury in the event of pressure relief. Pipe the
discharge to a drain. Provide piping that is the same
size as the safety relief valve outlet.

CAUTION

Figure 3.4: Safety Relief Valve Hook-Up with

Air Elimination

Figure 3.3: Safety Relief Valve Hook-Up

Installation with Air Elimination in
System Piping

Figure 3.2: Parallel Hook-Up with Water Chiller

WATER PIPING AND CONTROLS

9

C. PIPING FOR ZONED SYSTEMS

1. See Figures 3.5 and 3.6 for basic zoned system
layouts.

2. Run each zone pipe down then up to zone to
prevent air accumulation in piping.

3. If required, provide means to isolate and drain each
zone separately.

WATER PIPING AND CONTROLS

Figure 3.5: Zone Piping with Zone Valves

Figure 3.6: Zone Piping with Circulators

10

D. EXPANSION TANK

1. Consult the tank manufacturer’s instructions for
specific information relating to tank installation. Size
the expansion tank for the required system volume
and capacity. See Table 10.2 in Section 10 for boiler
water content.

2. Expansion tanks are available with built-in fill valves
and check valves for reducing supply water pressure
and maintaining minimum system pressure. Check
the design features of the tank and provide valves as
necessary. Refer back to Figure 3.1 for typical
expansion tank piping.

E. INDIRECT-FIRED WATER HEATER

If the boiler is to be used in conjunction with an indirect­fired water heater, refer to Figure 3.7 for typical piping.
Follow the instructions provided by the water heater
manufacturer. Pipe the water heater as a separate zone.

F. FREEZE PROTECTION

For new or existing systems that must be freeze­protected:

1. Glycol in hydronic applications is specially
formulated for this purpose. It includes inhibitors
which prevent the glycol from attacking metallic
system components. Make certain that the system
fluid is checked for the correct glycol concentration
and inhibitor level.

2. The glycol solution should be tested at least once a
year and as recommended by the glycol
manufacturer.

3. Glycol solutions expand more than water. For
example, a 50% by volume solution expands 4.8%
in volume for a temperature increase from 32°F
(0°C) to 180°F (82°C), while water expands 3% with
the same temperature rise. Allowance must be made
for this expansion in system design.

4. For more information, consult the PB Heat Water
Installation Survey and the glycol manufacturer.

WATER PIPING AND CONTROLS

Use only inhibited propylene glycol solutions of up to
50% by volume with water. Ethylene glycol is toxic
and can attack gaskets and seals used in hydronic
systems.

WARNING

Figure 3.7: Typical Piping with Indirect-Fired Water Heater

A. VENT PIPING AND CHIMNEY

1. Install vent piping in accordance with Venting of
Equipment part of the National Fuel Gas Code, ANSI
Z223.1/NFPA 54, sections 7.2, 7.3 or 7.4 of CAN/CSA
B149.1, Natural Gas and Propane Installation Code,
or applicable provisions of the local building codes.

2. A clay lined masonry chimney IS NOT acceptable
for use with this appliance. If venting this boiler into
a clay lined masonry chimney, the chimney must be
lined with a listed Category II vent system.

3. Follow the vent manufacturer’s instruction for proper
installation and assembly.

4. A horizontal condensate drain tee is required in the vent
connector between the boiler and chimney. Fill drain
trap with water. Pipe to drain or condensate receiver.

Tee de vidange horizontale condensat est nécessaire
dans l'évent. Connecteur entre la chaudière et une
cheminée. Remplissez égoutter piège avec de l'eau.
Tuyau pour drainer ou de condensat.

5. Use vent manufacturer’s appliance vent adapter to
connect vent system to vent damper.

6. A Category I atmospheric vented appliance may be
vented into the same vent system for the boiler.
Position the condensate drain tee between appliance
vent connectors and the common vent.

7. Install vent pipe to slope upward at least 1/4" per
lineal foot (21 mm per meter) between the draft
hood outlet and the chimney.

Installer le tuyau d’évent avec une pente ascendante
minimum de 21 mm au mètre (1/4 po au pied) à la
sortie du coupe-tirage et la cheminée.

8. Before connection of joints, inspect the vent pipe
interior for foreign objects such as tools, equipment,
rags, etc. and remove if present.

9. Do not connect vent connectors serving appliances
vented by natural draft into any portion of mechanical
draft systems operating under positive pressure.

10. Support horizontal portions of the venting system to
prevent sagging and accumulation of condensate by
use of metal strapping or equivalent means. Locate
supports at no more than 4 foot (1.2 meter) intervals.

Fournir un support à toute portion horizontale du
système d’évacuation à l’aide de courroies de métal
ou une méthode équivalente afin de l’empêcher de
s’affaisser. Placer les supports à des intervalles ne
dépassant pas cent vingt deux (122) centimètres
(4 po), ou en suivant les recommandations d’
installation du fabricant.

4. VENTING

VENTING

The MI85™boiler is a Category II atmospheric vented
appliance. The venting materials used must be listed
for Category II venting, such as AL294C. Plastic, non­metallic, vent materials are not acceptable for use
with this appliance.

NOTICE

Figure 4.1: Venting to a Lined Chimney

11

12

B. INTEGRAL DRAFT HOOD

1. The MI85™ boiler is equipped with a built-in draft
hood. This device is designed to:

a. provide for the ready escape of flue gases from

the boiler in the event of no draft.

b. prevent a backdraft from entering the boiler.

c. control stack draft during operation.

These tasks are accomplished without the extra
height requirements of a separate draft hood.

2. The draft hood relief opening is the large rectangular
passage at the front of the boiler. Make certain that
there are no obstructions to airflow in front of this
opening.

3. A vent safety shut-off switch is located within the
draft relief opening to shut off the boiler in case of a
blocked vent condition. See Section 7B for details
regarding this device. See Figure 6.1 in Section 6
(Electrical) for spill switch location.

4. The vent damper shall be mounted directly onto the
round draft hood outlet (vent connector) on top of
the boiler. See the Vent Damper Installation
Instructions below.

C. VENT DAMPER INSTALLATION –

GENERAL

1. Do not use one vent damper to control two or more
heating appliances. See Figure 4.2.

2. Follow these and the installation instructions that are
included with the vent damper. Observe the cautions
and warnings that accompany all instructions.

3. Make certain that minimum clearances provided in
the vent damper manufacturer’s instructions are
maintained and that adequate space is available for
damper access and service.

4. Orient the damper operator to facilitate connection
of the harness with the vent damper and boiler. Note
flue gas flow arrow on vent damper and orient as
required.

5. Damper must be in open position when main
burners are operating.

Le registre doit être en position ouverte lorsque le
brûleur principal de l’appareil fonctionne.

VENTING

Figure 4.2: Venting Multiple Appliances

13

D. BOILER REMOVAL FROM COMMON

VENTING SYSTEM

At the time of removal of an existing boiler, follow these
steps 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:

Au moment de retirer une chaudière existante, il est
important de suivre les étapes suivantes pour chaque
appareil raccordé au système d’évacuation commun qui
sont en service, alors que les autres appareils demeurant
raccordés au système d’évacuation commun ne sont pas
en service :

a. Seal any unused openings in the common venting

system.
Sceller toute ouverture du système d’évacuation

commun non utilisée.

b. 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.

Effectuer un contrôle visuel du système d’évacuation
pour vérifier la taille et la pente horizontale et
s’assurer qu’il n’existe aucun blocage ou obstruction,
fuite, corrosion ni tout autre problème pouvant
menacer la sécurité.

c. 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 any clothes dryers and any
appliance not connected to 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.

Dans la mesure du possible, fermer toutes les portes
et fenêtres de l’immeuble ainsi que toutes les portes
entre l’espace dans lequel les appareils qui
demeurent raccordés au système d’évacuation
commun se trouvent et le reste de l’immeuble.
Mettre en marche les sécheuses et tout autre appareil
non raccordé au système d’évacuation commun.
Mettre en marche tous les ventilateurs aspirant, tels
que les hottes de cuisinière et les ventilateurs de salle
de bain, en les faisant fonctionner à vitesse
maximum. Ne pas faire fonctionner les ventilateurs
aspirant d’été. Fermer les registres de foyers.

d. Place in operation the appliance being inspected.

Follow the lighting instructions. Adjust thermostat so
appliance will operate continuously.

Mettre en service l’appareil à inspecter. Suivre les
instructions concernant l’allumage. Régler le
thermostat afin que l’appareil fonctionne sans arrêt.

e. 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.

Vérifier toute fuite à l’orifice de décharge du coupe­tirage après que le brûleur ait fonctionné pendant 5
minutes. Utiliser la flamme d’une allumette ou d’une
chandelle ou encore la fumée d’une cigarette, d’un
cigare ou d’une pipe.

f. 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
conditions of use.

Après avoir établi que les résidus de combustion de
chaque appareil qui demeure raccordé au système
commun sont adéquatement évacués lorsque soumis
au test décrit ci-dessus, remettre en place les portes,
fenêtres, portes intérieures, ventilateurs aspirants,
registres de foyer et appareils fonctionnant au gaz.

g. Any improper operation of the common venting

system should be corrected so that the installation
conforms with the current edition of 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 the
National Fuel Gas Code, ANSI Z223.1/NFPA 54
and/or CAN/CSA B149.1, Natural Gas and Propane
Installation Code.

Tout fonctionnement inadéquat du système
d’évacuation commun doit être corrigé de manière à
respecter les normes du National Fuel Gas Code,
ANSI Z223.1/NFPA 54 et/ou des Codes d’installation
CAN/ACG B149. Lorsqu’il est nécessaire de modifier
les dimensions de toute portion du système
d’évacuation commun, ces dernières doivent être
modifiées de manière à respecter les dimensions
minimums indiquées dans les tableaux du chapitre «
Sizing of Category I Venting Systems » du National
Fuel Gas Code, ANSI Z223.1/NFPA 54 ou des Codes
d’installation CAN/ACG B149.

VENTING

1. Size and install the gas supply piping properly in
order to provide a supply of gas sufficient to meet
the maximum demand without undue loss of
pressure between the meter and the boiler.

2. Determine the volume of gas to be provided to the
boiler in cubic feet per hour. To obtain this value,
divide the Btu per hour rating (on the boiler rating
plate) by the heating value of the gas in Btu per
cubic feet. Obtain the heating value of the gas from
the gas supplier. As an alternative, use Table 5.1, 5.2
or 5.3 on the next page to obtain the volume of gas
to be provided to the boiler.

3. Use the value obtained above as the basis for piping
sizing. Size the gas piping in accordance with Table

5.4. Consult the National Fuel Gas Code ANSI
Z223.1/NFPA 54 and/or CAN/CSA B149.1, Natural
Gas and Propane Installation Code for proper sizing
options.

4. Locate the drop pipe adjacent to, but not in front of
the boiler.

5. Install a sediment trap. See Figure 5.1. Locate a tee
in the drop pipe at same elevation as the gas inlet
connection to the boiler. Extend the drop pipe to a
pipe cap.

6. Install a ground joint union ahead of the gas control
assembly to permit servicing of the control. Some
local codes require an additional service valve when
using the combination gas controls. If your code
requires such a valve, a suggested location is shown
in Figure 5.1.

7. Check piping for leaks.

Use an approved gas detector, a non-corrosive leak
detection fluid or other leak detection method. If
leaks are found, turn off all gas flow and repair as
necessary.

8. Disconnect the boiler and its individual shut-off valve
from the gas supply piping system during any
pressure testing of that system at test pressure in
excess of 1/2 psig (3.5 kPa).

Isolate the boiler from the gas supply piping system
by closing its individual service valve during any
pressure testing of the gas supply piping system at
test pressure equal to or less than 1/2 psig (3.5 kPa).

9. Minimum permissible supply pressure for purposes of
input adjustment:

Natural Gas 5.0″ WC (1.2 kPa)

Maximum permissible supply pressure to the boiler:

Natural Gas 13.5″ WC (3.5 kPa)

14

Table 5.1: Natural Gas

Model

Input

Cubic Feet / Hour Cubic Meters / Hour

MI85-03 60 1.7

MI85-04 90 2.5

MI85-05 120 3.4

MI85-06 150 4.2

5. GAS PIPING

Figure 5.1: Gas Connection to Boiler

When checking for leaks, do not use matches,
candles, open flames or other methods that provide a
source of ignition. This can ignite a gas leak,
resulting in fire or explosion.

WARNING

Use a pipe joint sealing compound that is resistant to
the action of liquefied petroleum gas. A non-resistant
compound may lose sealing ability in the presence of
this gas, resulting in a gas leak and fire or explosion
potential.

WARNING

Do not subject the gas valve to more than 1/2 psi (3.5
kPa) pressure. Doing so may damage the valve.

CAUTION

GAS PIPING

15

Table 5.2: Pipe Capacity

Capacity of pipe of different diameters and lengths in cubic feet per
hour [cubic meter per hour] with a pressure drop of 0.3 inches of water
(75 Pa) and specific gravity of 0.60. No allowance for an ordinary
number of fittings is required.

GAS PIPING

Pipe

Length in

Feet

[Meters]

3/4"

Pipe

1"

Pipe

1-1/4"

Pipe

1-1/2"

Pipe

10 [3.0] 278 [7.9] 520 [14.7] 1050 [29.7] 1600 [45.3]

20 [6.1] 190 [5.4] 350 [9.9] 730 [20.7] 1100 [31.1]

30 [9.1] 152 [4.3] 285 [8.1] 590 [16.7] 890 [25.2]

40 [12.2] 130 [3.7] 245 [6.9] 500 [14.2] 760 [21.5]

50 [15.2] 115 [3.3] 215 [6.1] 440 [12.5] 670 [19.0]

60 [18.3] 105 [3.0] 195 [5.5] 400 [11.3] 610 [17.3]

Maximum Capacity Correction Factors for
Specific Gravity other than 0.60.

Specific Gravity 0.50 0.55 0.60 0.65 0.70 0.75

Correction Factor 1.10 1.04 1.00 0.96 0.93 0.90

Specific Gravity 0.80 0.85 0.90 1.00 1.10 1.20

Correction Factor 0.87 0.84 0.82 0.78 0.74 0.71

Specific Gravity 1.30 1.40 1.50 1.60 1.70 1.80

Correction Factor 0.68 0.66 0.63 0.61 0.59 0.58

16

A. WIRING

1. See Figure 6.1 for location of wiring and controls.
Use Figures 6.2 and 6.3 to connect the boiler to a
power supply and to connect components to the
boiler.

2. Connect the boiler by a separate, permanently live
electrical supply line with a fused switch.

3. Connect the vent damper harness to the damper
motor as shown in Figure 6.1.

4. Adjust the thermostat heat anticipator to 0.2 Amp.

B. ZONED SYSTEM WIRING

See Figure 6.5 for typical wiring with zone valves. See
Figure 6.6 for typical wiring with zone circulators. When
wiring a zoned heating system, follow all applicable
codes, ordinances and regulations.

C. CONTROLS

1. For proper location of controls and accessories refer
to Figure 6.1 and Section 11.

2. See the attached control sheets for specific details
regarding the installation of the various controls.

3. This boiler is supplied with safety devices in addition
to the limit. For a description of these devices and
how they work to ensure the safe operation of the
boiler, see Section 7B.

4. If the circulator is mounted in the supply piping,
provide longer wiring harness as required.

ELECTRICAL

6. ELECTRICAL

This unit when installed must be electrically grounded in accordance with the requirements of the authority
having jurisdiction or, in the absence of such requirements, with the current edition of the

National Electrical

Code

, ANSI/NFPA 70 and/or the

Canadian Electrical Code

, Part 1 CSA C22.1, Electrical Code.

NOTICE

Figure 6.1: Wiring, Controls and Safety Devices

Install all electrical wiring in accordance with the National Electrical Code and local requirements.

Do not power zone valves directly from the boiler
limit. Doing so will greatly reduce the life of the
transformer. Use a separate transformer sized to
handle the total of all zone valve electrical loads.

NOTICE

17

ELECTRICAL

Figure 6.2: Wiring and Connection Diagram – Intermittent Ignition L8148E Control

Figure 6.3: Wiring Diagram – Intermittent Ignition 7600B Control

18

ELECTRICAL

Figure 6.4: Wiring Diagram – Intermittent Ignition 3200 Control

19

Figure 6.5: Intermittent Ignition System Operating Sequence

ELECTRICAL

20

ELECTRICAL

Figure 6.6: Zone Wiring with Zone Valves

Figure 6.7: Zone Wiring with Circulators

21

A. COMPLETING THE INSTALLATION

1. Confirm that all water, gas and electricity are
turned off.

2. Inspect the boiler combustion chamber for foreign
objects and remove if present.

3. Check physical condition of burners and pilot. Make
certain that there are no unusual bends or
perforations in the burners or pilot. Replace
components if necessary.

4. Verify that water piping, venting, gas piping and
electrical wiring and components are installed
properly. Refer back to previous sections of these
instructions as well as equipment manufacturer’s
instructions as necessary.

5. Fill the boiler and system with water, making certain
to vent all air from all points in the system. To check
water level in the system, open and close each vent
in the system. Water should exit from each vent
when it is opened.

6. The pressure reducing valve on the fill line will
typically allow the system to be filled and pressurized
to 12 psi (83 kPa). Consult the valve and expansion
tank manufacturer for more specific information.

7. Check joints and fittings throughout the system for
leaks. If leaks are found, drain the system and repair
as required.

8. Connect a manometer to the gas valve on the valve
outlet (gas manifold). Use the 1/8 NPT tapping
provided.

9. Confirm that the gas supply pressure to the boiler is
above the minimum and below the maximum values
for the gas being used. See the end of Section 5 for
these values. If a supply pressure check is required,
isolate the boiler and gas valve before performing
the pressure check. If the supply pressure is too high
or too low, contact the gas supplier.

10. Turn on electricity and gas to boiler.

11. Light the boiler by following the Lighting/Operating
Instructions label mounted to the jacket panel. The
initial ignition may require several tries as the piping
is purged of air.

12. Use the sequence descriptions in Figure 6.5 in
Section 6 (Electrical) to follow light-off and shutdown
sequences and to assist in diagnosing problems. If
the boiler does not function properly, consult Section
8, Troubleshooting.

13. The gas manifold and control assembly are made of
gas-tight, completely factory assembled and installed
components of the base assembly. See Figure 7.1
and 7.2.

Figure 7.1: Gas Valve, Manifold and Burner

Assembly – Intermittent Ignition

Figure 7.2: Valve Tapping and Adjustment Screw

Locations

START-UP PROCEDURES

7. START-UP PROCEDURES

22

START-UP PROCEDURES

Figure 7.3: Operating Instructions

23

Figure 7.4: Operating Instructions

START-UP PROCEDURES

24

B. CONTROL DESCRIPTIONS

See Figure 6.1 in Section 6 (Electrical) for locations of
these devices.

1. FLAME ROLL-OUT SAFETY SHUT-OFF SWITCH
(FLAME ROLL-OUT SWITCH) – A thermally
activated switch located between the first burner
from the left and the manifold bracket. The flame
roll-out safety shut-off switch will sense excessive
temperature caused by continued flame roll-out and
shut down main burner gas. This is a non-recycling
switch that must be replaced once it has been
activated and the cause of the roll-out eliminated.

2. VENT SAFETY SHUT-OFF SWITCH (SPILL
SWITCH) – A thermally activated, manually
resetable switch located in the draft hood relief
opening. If venting system becomes partially or
totally blocked, the vent safety shut-off switch will
sense excessive temperature caused by flue products
exiting the draft hood relief opening and shut down
main burner gas.

3. LIMIT WITH LOW WATER CUT-OFF – A Beckett
7600B or Hydrolevel 3200 control incorporate a
thermally activated adjustable switch that will shut
down main burner gas if the supply water temp
exceeds the control setting. It will also shut down
main burner gas if the water level in the boiler drops
below the control’s sensing well. The temperature
switch will automatically reset when the boiler supply
water temp drops below the control setpoint. The
low water cut-off switch will automatically reset when
the water level is above the control’s sensing well.

4. LOW WATER CUT-OFF (FOR GRAVITY SYSTEMS
OR HOT WATER BOILERS INSTALLED ABOVE
RADIATION LEVEL) – If limit control does not
incorporate a low water cut-off feature then install a
level-sensing device (float or probe) located in supply
piping near the boiler.

C. ADJUSTMENT OF GAS PRESSURE

REGULATOR

1. Using the manometer setup installed in part 7A, set
manifold pressure as follows for various gases.

Natural Gas . . .3.5″ Water Column (0.9 kPa)

2. To adjust gas pressure, turn adjusting screw of gas
pressure regulator counterclockwise to decrease
pressure, clockwise to increase pressure. Refer to
Figure 7.3 for location of gas pressure regulator.
Replace the cap screw when adjustment is complete.

3. In no case should the final manifold pressure vary
more than ±0.3 inches water column (0.07 kPa)
from the above specified pressures. Any necessary
major changes in the flow should be made by
changing the size of the burner orifice spuds.

4. When adjustment is complete, turn off boiler, gas
flow and electricity to boiler. Remove manometer
connection from valve and plug tapping with plug
provided. Turn utilities back on and resume
checkout.

D. CHECKING BURNER INPUT

1. Refer to rating label mounted on the jacket top panel
to obtain the rated BTU per hour input. In no case
shall the input to the boiler exceed the value shown
on the rating label.

2. Check input by use of the following formulas
(PB Heat, LLC suggests reading meter for 2 Cu. Ft.):

U.S. Customary Units

Input (BTU/Hr.)= 3600 x F x H

T

Where:

3600 = Seconds per hour

F = Cubic Feet of Gas Registered on Meter

H = Heat Value of Gas in BTU/Cubic Feet

T = Time in Seconds the Meter is Read

SI Metric Units

Input (kW)= 3600 x F x H

T x 3.6

Where:

3600 = Seconds per hour

3.6 = Megajoule (MJ) per kilowatt hour (kwhr)
F = Cubic Meters of Gas Registered on Meter

H = Heating Value of Gas in MJ/Cubic Meter

T = Time in Seconds the Meter is Read

3. As an alternative, use Table 7.1(a) and 7.1(b). Use
the heating value provided by gas supplier. Use a
stopwatch to record the time it takes for 2 cubic feet
(0.0566 cubic meter) of gas to pass through the
meter. Read across and down to determine rate.

Burner inputs in Btu/hr for various meter timings and heat
values. (Table based on 2 cubic feet of gas through meter).

START-UP PROCEDURES

Table 7.1a: Meter Conversion – Natural Gas

(U.S. Customary Units)

Time that

meter is

read (sec)

Heat Value of Gas

(Btu/cubic foot)

1000 1025 1050

25 288000 295200 302400
30 240000 246000 252000
35 205714 210857 216000
40 180000 184500 189000
45 160000 164000 168000
50 144000 147600 151200
55 130909 134182 137455
60 120000 123000 126000
65 110769 113538 116308
70 102857 105429 108000
75 96000 98400 100800
80 90000 92250 94500
85 84706 86824 88941
90 80000 82000 84000

95 75789 77684 79579
100 72000 73800 75600
105 68571 70286 72000
110 65455 67091 68727
115 62609 64174 65739
120 60000 61500 63000
125 57600 59040 60480

25

Burner inputs in kW for for various meter timings and
heat values. (Table based on 0.0566 cubic meter of gas
through meter).

E. CHECK-OUT PROCEDURE

1. After starting the boiler, be certain all controls are
working properly. Check to be sure that the limit will
shut off the boiler in the event of excessive water
temperature. This can be done by lowering the limit
setting until the main burners shut down. When
proper limit function is confirmed, return the dial to
its previous setting.

2. Intermittent Ignition System—To check operation of
the ignition system safety shut-off features:

a. Refer to Figure 7.3 Operating Instructions for

placing the boiler in operation and Figure 6.5,
Intermittent Ignition System Operating Sequence.

b. Observe boiler operation through one complete

cycle.

3. Low Water Cut-Off (if used) – Consult the
manufacturer’s instructions for the low water cut-off
operational check procedure. Note that low water
cut-off feature is incorporated in Beckett 7600B Limit
Control and the Hydrolevel 3200 Control.

4. Check the system to make sure there are no leaks or
overfilling problems which might cause excessive
make-up water to be added. Make-up water causes
liming in the boiler and brings in oxygen. Oxygen
can cause severe damage to the boiler though
oxygen corrosion pitting.

5. Check the expansion tank and automatic fill valve (if
used) to confirm that they are operating correctly. If
either of these components causes high pressure in
the system, the boiler relief valve will weep or open,
allowing fresh water to enter the system.

6. Do not allow the system controls to subject the boiler
to excessively low water temperatures, which would
cause condensation of flue gases and corrosion of
the boiler. Operate the boiler at a temperature above
130°F (54°C). Adjust the boiler limit as required to
maintain boiler temperature above this level.

7. Check the general condition of the system including
piping support, joints, etc. Check cleanliness of the
radiators, baseboard units and/or convectors. Clean
them to the extent possible. If radiators do not heat
evenly, vent any remaining air from them.

8. Review operation and User’s Information Manual
with end-user.

9. Complete the Warranty Card and submit it to
PB Heat, LLC.

10. Hang the Installation, Operation and Maintenance
Manual and User’s Information Manual in an
accessible position near the boiler.

START-UP PROCEDURES

Table 7.1b: Meter Conversion – Natural Gas

(SI Metric Units)

Time that

meter is

read (sec)

Heat Value of Gas

(MJ/cubic meter)

37.26 38.19 39.12

25 84.36 86.46 88.57
30 70.30 72.05 73.81
35 60.25 61.76 63.26
40 52.72 54.04 55.35
45 46.86 48.03 49.20
50 42.18 43.23 44.28
55 38.34 39.30 40.26
60 35.15 36.03 36.90
65 32.44 33.25 34.06
70 30.13 30.88 31.63
75 28.12 28.82 29.52
80 26.36 27.02 27.68
85 24.81 25.43 26.05
90 23.43 24.02 24.60

95 22.20 22.75 23.31
100 21.09 21.62 22.14
105 20.08 20.59 21.09
110 19.17 19.65 20.13
115 18.34 18.80 19.25
120 17.57 18.01 18.45
125 16.87 17.29 17.71

26

A. SHUT-DOWN CAUSED BY PILOT

OUTAGE, BLOCKED VENT SHUT-OFF

SWITCH OR FLAME ROLL-OUT SAFETY

SHUT-OFF SWITCH

In the event of a shut-down caused by a pilot outage,

action of the blocked vent shut-off switch or flame roll-

out safety shut-off switch effecting a shut-down of the

main burners:

a. Refer to the Lighting/Operating Instructions in

Figures 7.3 and 7.4 to properly turn off the gas to

the boiler.
b. Turn off all electric power to the boiler.
c. Call a qualified heating service organization or local

gas company and have the cause of the shut-down

investigated and corrected.
d. Refer to Lighting/Operating Instructions to

re-start boiler.

B. TROUBLESHOOTING GUIDES

Use Table 8.1 to assist in determining causes and
providing corrective actions to boiler problems. Refer
also to Figure 8.1 to troubleshoot the Intermittent
Ignition System Control. These guides must be used
only by qualified service technicians. These individuals
must follow all applicable codes and regulations in repair
of any boiler problems.

TROUBLESHOOTING

8. TROUBLESHOOTING

Should overheating occur or the gas supply fail to
shut off, do not turn off or disconnect the electrical
supply to the pump. This may aggravate the problem
and increase the likelihood of boiler damage. Instead,
shut off the gas supply at a location external to the
appliance.

CAUTION

Do not use this appliance if any part has been under
water. Improper or dangerous operation may result.
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

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

CAUTION

When servicing or replacing items that communicate
with the boiler water, be certain that:

●

There is no pressure on the boiler.

●

The boiler is not hot.

●

The power is off.

When servicing the gas valve or pilot, be certain that:

●

The gas is off.

●

The electricity is off.

DANGER

Identifier tous les câbles avant de les débrancher au
moment d’effectuer l’entretien des commandes. Des
erreurs dans le raccordement des câbles
d’alimentation peuvent causer un fonctionnement
inadéquat et dangereux. Vérifier le bon
fonctionnement après les travaux d’entretien.

AVERTISSEMENT

27

TROUBLESHOOTING

Table 8.1: Boiler Troubleshooting Guide

PROBLEM POSSIBLE CAUSES CORRECTIVE ACTIONS

Burners not functioning.

1. No power. 1. Check line voltage wiring and fuses.

2. Limit (Aquastat) not working. 2. Check wiring and contacts, relay, temperature
setting. Clean and adjust as necessary.

3. Flame rollout switch open. 3. Replace switch. Locate cause and correct.

4. Blocked vent switch open. 4. Reset blocked vent switch. Locate cause and correct.

5. Gas off at boiler gas valve. 5. Start boiler using Lighting/Operating Instructions.

6. Gas off external to boiler. 6. Check any gas valves in the line.

7. Plugged orifice spuds. 7. Check, clean and re-install.

8. Defective gas valve. 8. Use Figure 8.1 to troubleshoot intermittent
ignition gas valve. Replace if necessary.

9. Improper wiring. 9. Check and correct in accordance with wiring
diagrams in Section 6.

10. Vent damper malfunctioning. 10. Refer to vent damper manufacturer’s instructions.
Replace if necessary.

Burners will not shut
down.

1. Defective gas valve. 1. Use Figure 8.1 to troubleshoot intermittent
ignition gas valve. Replace if necessary.

2. Short circuit. 2. Check and correct wiring.

Flashback or burning
at orifice spuds.

1. Manifold gas pressure too low. 1. Adjust to proper pressure.

2. Improperly sized/drilled orifice spuds. 2. Install correct spuds.

3. Leaking gas valve. 3. Replace valve.

4. Burrs on orifice. 4. Remove burrs.

5. Low supply gas pressure. 5. Contact gas supplier if natural gas.

6. Excessive downdraft or draft problems in

boiler room.

6. Check air supply, ventilation and venting system.

Delayed ignition. 1. Insufficient pilot flame.

1. Increase pilot gas flow.

2. Pilot burner/orifice clogged. 2. Clean pilot burner and orifice.

3. Overfiring. 3. Reduce rate to input on rating label.

4. Misaligned burners or pilot. 4. Realign burners or pilot.

5. Draft problem in boiler room. 5. Check air supply, ventilation and venting system.

Boiler not heating
properly.

1. Underfiring. 1. Increase rate to input on rating label.

2. Limit set too low. 2. Reset Aquastat to higher setting.

3. Air in system. 3. Vent air from all points in system.

4. Circulator malfunctioning. 4. Check circulator, replace if necessary.

5. Circulation system clogged. 5. Shut down and cool boiler, drain and flush system.

6. Incorrect thermostat heat anticipator setting. 6. Adjust heat anticipator.

Fumes or gas odors

1. Leaks in gas piping or fittings. 1. Locate and repair or replace.

2. Leaks in gas service line or meter. 2. Shut down boiler and notify gas provider.

3. Obstructed chimney. 3. Check, repair and/or clean chimney.

4. Obstructed flueways or vent. 4. Clean flueways or vent and remove obstructions.

5. Undersized chimney or vent, high draft loss

in vent.

5. Check National Fuel Gas Code and vent
manufacturer’s recommendations.

6. Draft problem in boiler room. 6. Check air supply, ventilation and venting system.

7. Overfiring. 7. Reduce rate to input on rating label.

8. Vent damper malfunctioning. 8. Refer to vent damper manufacturer’s instructions.
Replace if necessary.

28

Figure 8.1: Intermittent Ignition System Troubleshooting Sequence

TROUBLESHOOTING

STAR T
BEFORE TROUBLESHOOTING,
FAMILIARIZE YOURSELF WITH

THE STARTUP AND

CHECKOUT PROCEDURES.

TURN GAS SUPPLY OFF,

TURN THERMOSTAT

(CONTROLLER) TO
“CALL FOR HEAT.”

NOTE: “CALL FOR HEAT” 24 VAC SUPPLY IS CONNECTED TO THE 24 V TERMINAL ON THE CONTROL.

POWER TO

MODULE? (24 V

NOMINAL)

YES

SPARK
ACROSS
IGNITER/

SENSOR

GAP?

YES

TURN GAS SUPPLY
ON AND RECYCLE

“CALL FOR HEAT.”

PILOT BURNER

LIGHTS?

YES

SPARK

STOPS WHEN

PILOT IS

LIT?

YES

CHECK LINE VOLTAGE POWER, LOW VOLTAGE TRANSFORMER, LIMIT CONTROLLER, THERMOSTAT (CONTROLLER), AND WIRING ALSO.

NO

CHECK AIR PROVING SWITCH ON COMBUSTION AIR BLOWER SYSTEM (IF USED) AND THAT THE VENT DAMPER END SWITCH (IF USED)
IS MADE.

PULL IGNITION LEAD AND

NO

CHECK SPARK AT MODULE.

CHECK IGNITION CABLE, GROUND WIRING, CERAMIC INSULATOR, AND SPARK GAP ARE CORRECT.
CHECK BOOT OF THE IGNITION CABLE FOR SIGNS OF MELTING OR BUCKLING, TAKE PROTECTIVE ACTION TO SHIELD CABLE
AND BOOT FROM EXCESSIVE TEMPERATURES.

CHECK THAT ALL MANUAL GAS VALVE S ARE OPEN, SUPPLY TUBING AND PRESSURES ARE GOOD, AND PILOT BURNER
ORIFICE IS NOT BLOCKED (PILOT GAS FLOWING).
CHECK ELECTRICAL CONNECTIONS BETWEEN MODULE AND PILOT OPERATOR ON GAS CONTROL.

NO

CHECK FOR 24 VAC ACROSS PV-MV/PV TERMINALS ON MODULE. IF VOLTAGE IS OKAY, REPLACE GAS CONTROL.
IF NOT, REPLACE MODULE.
NOTE: IT MAY BE NECESSARY TO RECYCLE THE ‘CALL FOR HEAT” MORE THAN ONCE TO CLEAR THE PILOT SUPPLY TUBES OF AIR.

NOTE: IF CONTROL GOES INTO LOCKOUT OR RETRY DELAY, RESET THE “CALL FOR HEAT.”
CHECK CONTINUITY OF IGNITION CABLE AND GROUND WIRE.
CLEAN FLAME ROD.
CHECK ELECTRICAL CONNECTIONS BETWEEN FLAME ROD AND MODULE.

NO

CHECK FOR CRACKED CERAMIC FLAME ROD INSULATOR.
CHECK THAT PILOT FLAME COVERS FLAME ROD AND IS STEADY AND BLUE.
ADJUST PILOT FLAME.
IF PROBLEM PERSISTS REPLACE MODULE.

SPARK OK? NO

YES

REPLACE MODULE

MAIN BURNER

LIGHTS?

YES

SYSTEM

RUNS UNTIL “CALL

FOR HEAT”

ENDS?

YES

“CALL FOR HEAT” ENDS

SYSTEM

SHUTS

OFF?

YES

REPEAT PROCEDURE UNTIL
TROUBLE FREE OPERATION

IS OBTAINED.

CHECK FOR 24 VAC ACROSS PV-MV/PV TERMINALS ON MODULE. IF NO VOLTAGE, REPLACE MODULE.

NO

CHECK ELECTRICAL CONNECTIONS BETWEEN MODULE AND GAS CONTROL INCLUDING SAFETY CONTROLS WIRED IN THE CIRCUIT.
IF OKAY, REPLACE GAS CONTROL.

NOTE: IF CONTROL GOES INTO LOCKOUT OR RETRY DELAY, RESET THE “CALL FOR HEAT.”
CHECK CONTINUITY OF IGNITION CABLE AND GROUND WIRE.
NOTE: IF GROUND IS POOR OR ERRATIC, SHUTDOWNS MAY OCCUR OCCASIONALLY EVEN THOUGH OPERATION IS NORMAL
AT THE TIME OF CHECKOUT.
CHECK THAT PILOT FLAME COVERS FLAME ROD AND IS STEADY AND BLUE, PILOT FLAME MUST NOT BE MOVING AROUND DUE TO

NO

OUTSIDE AIR FLOWS, ETC.
ADJUST PILOT FLAME. CHECK GAS PRESSURE MEETS APPLIANCE SPECIFICATIONS WHILE APPLIANCE MAIN BURNER ON AND ALL
OTHER GAS APPLIANCES ON THE SUPPLY ARE OPERATING AT FULL RATE.
IF CHECKS ARE OKAY, REPLACE MODULE.

CHECK FOR PROPER THERMOSTAT (CONTROLLER) OPERATION.

NO

REMOVE MV LEAD AT MODULE, IF VALVE CLOSES, RECHECK TEMPERATURE CONTROLLER AND WIRING. IF NOT, REPLACE
GAS CONTROL.

29

MAINTENANCE

9. MAINTENANCE

WARNING

Product Safety Information

Refractory Ceramic Fiber Product

This appliance contains materials made from refractory ceramic fibers (RCF). Airborne RCF,
when inhaled, have been classified by the International Agency for Research on Cancer
(IARC), as a possible carcinogen to humans. After the RCF materials have been exposed to
temperatures above 1800°F (980°C), they can change into crystalline silica, which has been
classified by the IARC as carcinogenic to humans. If particles become airborne during
service or repair, inhalation of these particles may be hazardous to your health.

Avoid Breathing Fiber Particulates and Dust

Suppliers of RCF recommend the following precautions be taken when handling these
materials:

Precautionary Measures:
Provide adequate ventilation.
Wear a NIOSH/MSHA approved respirator.
Wear long sleeved, loose fitting clothing and gloves to prevent skin contact.
Wear eye goggles.
Minimize airborne dust prior to handling and removal by water misting the material and
avoiding unnecessary disturbance of materials.
Wash work clothes separately from others. Rinse washer thoroughly after use.
Discard RCF materials by sealing in an airtight plastic bag.

First Aid Procedures:
Inhalation: If breathing difficulty or irritation occurs, move to a location with fresh clean air.
Seek immediate medical attention if symptoms persist.
Skin Contact: Wash affected area gently with a mild soap and warm water. Seek immediate
medical attention if irritation persists.
Eye Contact: Flush eyes with water for 15 minutes while holding eyelids apart. Do not rub
eyes. Seek immediate medical attention if irritation persists.
Ingestion: Drink 1 to 2 glasses of water. Do not induce vomiting. Seek immediate medical
attention.

30

A. GENERAL

1. Disconnect this boiler from the gas supply piping
during any pressure testing of the gas system.

2. Check pipes adjacent to cold walls or in unheated
spaces. Insulate and tape them if necessary to be
sure they can’t freeze up. Keeping the water moving
at all times will reduce the likelihood of freezing. See
Section 3 for glycol instructions.

3. If there is considerable foreign matter in the boiler
water, the boiler should be shut down and allowed to
cool, then drained and thoroughly flushed out. Use
the drain valve at the bottom of the return
connection to drain the boiler. Pipe the drain cock to
a suitable drain or containment device if a glycol
solution is used. Flush the system to remove
remaining matter. If there is evidence that hard scale
has formed on the internal surfaces, the boiler
should be cleaned by chemical means as prescribed
by a qualified water treatment specialist.

B. DAILY (WITH BOILER IN USE)

Daily boiler observation can be performed by the owner.
If any potential problems are found, a qualified installer
or service technician/agency must be notified.

1. Remove any combustible materials, gasoline and
other flammable liquids and substances that generate
flammable vapors from the area where the boiler is
contained. Make certain that the boiler area has
ample air for combustion and ventilation and that
there are no obstructions to the free flow of air to
and from the boiler.

2. Observe general boiler conditions (unusual noises,
vibrations, etc.)

3. Observe operating temperature and pressure on the
combination gauge located on the left side of the
boiler. Boiler pressure should never be higher than
5 psi (35 kPa) below the rating shown on the safety
relief valve; 25 psig (172 kPa) maximum for a 30
psig (207 kPa) rating, 45 psig (310 kPa) maximum
for a 50 psig (345 kPa) rating). The valve rating can
be found on the top of the safety relief valve (see
Figure 5 for location of the safety relief valve).
Boiler temperature should never be higher than
250°F (121°C).

4. Check for water leaks in boiler and system piping.

5. Smell around the appliance area for gas. If you smell
gas, follow the procedure listed in the
Lighting/Operating Instructions in Section 7.

C. WEEKLY (WITH BOILER IN USE)

1. Flush float-type low-water cut-off (if used) to remove
sediment from the float bowl as stated in the
manufacturer’s instructions.

D. MONTHLY (WITH BOILER IN USE)

1. Check boiler room floor drains for proper functioning.

2. Per valve manufacturer’s instructions, check function
of the safety relief valve. Check valve piping to
determine that it is properly installed and supported.

3. Test low-water cut-off (if used) as described by the
manufacturer.

4. Test limit as described in Section 7F, “Check-Out
Procedure.”

5. Test function of gas safety shut-off features as
described by gas valve and ignition control
manufacturer.

6. Cycle the boiler at least once and check operation of
the vent damper.

E. ANNUALLY (BEFORE START OF HEATING

SEASON)

1. Check flueways and burners for cleanliness and
clean if necessary. Use the following procedure if
cleaning is required:

a. Refer to the Lighting/Operating Instructions in

Figures 7.3 and 7.4 to properly turn off the gas
to the boiler.

b. Turn off all electrical power to the boiler.

c. Remove burners and brush orifice spuds lightly

using a soft bristle brush.

d. Remove the vent pipe, vent damper, top jacket

panels and flue collector/draft diverter. Remove
baffles.

e. Brush flueways with wire brush.

f. To the extent possible, inspect inside of vent pipe

and vent damper for obstructions in flow or vent
damper movement. Remove or replace as
necessary.

g. Re-install baffles. When replacing the flue

collector/draft hood, be certain that the blanket
seal between the flue collector and top section
makes a tight seal to prevent leakage of the
products of combustion.

MAINTENANCE

When servicing or replacing components, be
absolutely certain that the following conditions are
met:

●

Water, gas and electricity are off.

●

The boiler is at room temperature.

●

There is no pressure in the boiler.

DANGER

31

h. Re-install the top of the jacket, vent damper and

vent pipe.

i. Re-install burners.

2. Inspect entire venting system for corrosion, support
and joint integrity. Repair as necessary.

3. Check the pilot and main burner flame. See Figures

9.1 and 9.2. The pilot should provide a steady flame
enveloping 3/8″ to 1/2″ (1 cm to 1.2 cm) of the
flame sensor. If required, adjust the pilot as stated in
the gas valve manufacturer’s instructions. The main
burner flame inner cone should be approximately
1-1/2″ (4 cm) high and should have a very sharp,
blue color characteristic.

MAINTENANCE

Figure 9.1: Intermittent Pilot and Main

Burner Flame

32

BOILER DIMENSIONS & RATINGS

10. BOILER DIMENSIONS & RATINGS

Table 10.2: Series MI85™ Boiler Ratings

1 Net water ratings based on an allowance of 1.15.
2 Consult factory before selecting a boiler for installations having unusual piping and pickup requirements, such as intermittent system operation, extensive piping

systems, etc.

3 Heating Capacity and Annual Fuel Utilization Efficiency (AFUE) ratings are based on U.S. Government test.

Table 10.1: Series MI85™ Boiler Dimensions

SERIES MI85™ BOILER DIMENSIONS

Boiler
Model

Number

Jacket

Left of Jacket to

c/l of Vent “D”

Rear of Jacket to

c/l of Vent “E”

Vent Connector

Size “F”

Length (Depth)

“A”

Width

“B”

To Floor

“C”

inch mm inch mm inch mm inch mm inch mm inch mm

MI85-03 26-5/8 676 12-1/2 318 31-3/8 797 6-1/4 159 20-13/16 529 4 101
MI85-04 26-5/8 676 15-7/8 403 31-3/8 797 7-11/16 195 20-13/16 529 5 127
MI85-05 26-5/8 676 19-1/4 489 31-3/8 797 9-5/8 244 21-13/16 554 6 152
MI85-06 26-5/8 676 22-5/8 575 31-3/8 797 11-5/16 287 21-13/16 554 6 152

Figure 10.1: Boiler Views

SERIES MI85™ BOILER RATINGS

Series MI85™

Boiler

Model

Number

Input

Heating

Capacity³

Net Ratings

Water¹,²

Seasonal

Efficiency

Intermittent

Ignition³

MBH kW MBH kW MBH kW AFUE

MI85-03 60 18 51 15 44 13 85.0
MI85-04 90 26 77 22 67 20 85.0
MI85-05 120 35 102 30 89 26 85.1
MI85-06 150 44 128 38 111 32 85.1

Water

Content

Gallon Liter

4.72 17.87

6.00 22.71

7.28 27.55

8.56 32.40

33

REPAIR PARTS

Figure 11.1: Base/Combustible Floor Pan

REPAIR PARTS

SERIES MI85™ GAS BOILER

Repair parts are available from your local PB Heat, LLC distributor or from Parts To Your
Door at 1 [phone] (www.partstoyourdoor.com). Use the figures and tables on pages
33-39 to assist in ordering parts.

Note: Remember to include boiler model number and serial number when ordering parts.

11. REPAIR PARTS

Table 11.1: Base/Combustible Floor Pan

Description

Quantity
Required

Stock
Code

1

Base Assembly – MI85-03 – 7800
Base Assembly – MI85-04 – 7801
Base Assembly – MI85-05 – 7802

Base Assembly – MI85-06 – 7803
2 Observation Cover Door – 51771
3 Base Blanket Seal – 50867

4

Combustible Floor Pan Assembly – MI85-03 – 90700

Combustible Floor Pan Assembly – MI85-04 – 90701

Combustible Floor Pan Assembly – MI85-05 – 90702

Combustible Floor Pan Assembly – MI85-06 – 90703

34

REPAIR PARTS

Figure 11.2: Manifold

Figure 11.3: Gas Valve and Pilot (Intermittent Ignition)

35

REPAIR PARTS

Table 11.2: Manifold, Gas Valve and Pilot

Description

Quantity
Required

Stock
Code

5

Steel Burner – MI85-03 3 51537

Steel Burner – MI85-04 5 51537

Steel Burner – MI85-05 7 51537

Steel Burner – MI85-06 9 51537

6 Steel Burner w/ Spark & SV Pilot Bracket 1 51539

7

Gas Manifold – MI85-03 – 50978

Gas Manifold – MI85-04 – 50979

Gas Manifold – MI85-05 – 50980

Gas Manifold – MI85-06 – 50981

8

Orifice Spud, #50 Natural Gas – MI85-03 4 X4014-50

Orifice Spud, #50 Natural Gas – MI85-04 6 X4014-50

Orifice Spud, #50 Natural Gas – MI85-05 8 X4014-50

Orifice Spud, #50 Natural Gas – MI85-06 10 X4014-50

9

Honeywell VR8204A-2001 Gas Valve Spark – Natural Gas MI85-03 thru MI85-05 – 50583

Honeywell VR8304M-4002 Gas Valve Spark – Natural Gas MI85-06 – 50589

10 Honeywell Q348A-1002 Spark – 50558

36

Figure 11.4: Block/Draft Hood

Figure 11.5: Jacket

REPAIR PARTS

37

Table 11.3: Block/Draft Hood & Jacket

Description

Quantity
Required

Stock
Code

12

Block Assembly – MI85-03 – 90419

Block Assembly – MI85-04 – 90420

Block Assembly – MI85-05 – 90421

Block Assembly – MI85-06 – 90422

13

Flue Collector/Draft Hood – MI85-03 – 90858

Flue Collector/Draft Hood – MI85-04 – 90859

Flue Collector/Draft Hood – MI85-05 – 90512

Flue Collector/Draft Hood – MI85-06 – 90513

14 Flue Collector Blanket Seal (specify length needed) – 50866

15

Flue Baffles – MI85-03 2 51609

Flue Baffles – MI85-04 3 51609

Flue Baffles – MI85-05 4 51609

Flue Baffles – MI85-06 5 51609

16

Jacket Assembly (Complete Jacket*) – MI85-03 – 90445

Jacket Assembly (Complete Jacket*) – MI85-04 – 90446

Jacket Assembly (Complete Jacket*) – MI85-05 – 90447

Jacket Assembly (Complete Jacket*) – MI85-06 – 90448

*Complete Jacket Consists of:

16A Left Side Panel

16B Right Side Panel

16C Rear Panel

16D Top Upper Front Panel

16E Inner Front Baffle Panel

16G Removable Front Panel

REPAIR PARTS

38

Figure 11.6: Controls/Circulator/Vent Damper

REPAIR PARTS

39

Table 11.4: Controls/Circulator/Vent Damper & Conversion Kits

Description

Quantity
Required

Stock
Code

23 Limit w/ 3/4" Well (specify control model) – –

24 Temperature-Pressure Gauge – 51324

25

Safety Relief Valve, 30 PSI, Conbraco 10-408-05 – 50501

Safety Relief Valve, 50 PSI, Watts #350 – 99950

26 Flame Roll-Out Safety Shut-Off Switch – 51587

27 Blocked Vent Shut-Off (Spill) Switch – 50044

28

Vent Damper – MI85-03 1 90805

Vent Damper – MI85-04 1 90612

Vent Damper – MI85-05, MI85-06 1 90613

REPAIR PARTS

40

NOTES

MI85

™

Boilers

Series

Gas

Installation,
Operation &
Maintenance
Manual

TO THE INSTALLER:

This manual is the property of the owner and must
be affixed near the boiler for future reference.

TO THE OWNER:

This boiler should be inspected annually by a
Qualified Service Agency.

MI8084 R1 (3/16-5C)

Printed in U.S.A.©2016 PB Heat, LLC. All rights reserved.

PB HEAT, LLC

131 S. CHURCH STREET • BALLY, PA 19503

ASME