Patterson-Kelley MOD-04 Installation instructions

PATTERSON-KELLEY
THERMIFIC®
MODU-FIRE® GAS-FIRED BOILER
Installation and Owner's Manual
Installation Date:_______________________
100 Burson Street, P.O. Box 458,
East Stroudsburg, PA 18301
Telephone: [phone], Facsimile: [phone]
www.pkboilers.com
C.S.A Design-Certified
Complies with ANSI Z21.13/CSA 4.9
Gas-Fired Low Pressure Steam and Hot Water Boilers
ASME Code, Section IV
Certified by Patterson-Kelley
C.S.A Design-Certified
Complies with ANSI Z21.13/CSA 4.9
Gas-Fired Low Pressure Steam and Hot Water Boilers
MOD-04

Modu-Fire® Gas-Fired Boiler Table of Contents
1.0 INTRODUCTION........................................1
2.0 SAFETY......................................................1
2.1 General.......................................................1
2.2 Training.......................................................1
2.3 Safety Features ..........................................1
2.4 Safety Labels..............................................2
2.5 Safety Precautions......................................2
2.5.1 Electrical Hazards.................................2
2.5.2 Burn, Fire, and Explosion Hazards.......2
2.5.3 Crush Hazards......................................3
2.5.4 Chemical Hazards................................3
2.5.5 Pressure Hazards.................................4
2.5.6 Slip, Fall Hazards .................................4
3.0 INSTALLATION..........................................5
3.1 Receiving and Storage ...............................5
3.1.1 Initial Inspection....................................5
3.1.2 Storage Prior to Installation..................5
3.2 Compliance with Codes..............................5
3.3 Setup...........................................................5
3.3.1 Foundation............................................5
3.3.2 Placement.............................................5
3.3.3 Clearances ...........................................6
3.4 Electrical Connections................................6
3.5 Combustion Air ...........................................7
3.6 Flue Venting................................................7
3.6.1 Vent Elbows..........................................8
3.6.2 Barometric Damper ..............................8
3.6.3 Automatic Vent Damper .......................8
3.6.4 Flue Connection ...................................8
3.6.5 Vent Termination..................................8
3.6.6 Removing an Existing Boiler ................9
3.7 Gas Piping ..................................................9
3.7.1 Gas Supply Piping by Installer ...........11
3.7.2 Gas Bleeds and Vents by Installer.....11
3.8 Boiler Water Piping...................................11
3.8.1 Piping Design......................................11
3.8.2 Boiler Inlet and Outlet Connections....12
3.8.3 Boiler Water Piping by Installer...........12
3.8.4 Flushing and Filling.............................13
3.8.5 Water Quality ......................................13
3.9 Burner and Ignition System.......................13
3.9.1 Inspection............................................13
3.10 Pre-Start Check List................................13
3.11 Safety Checks.........................................14
3.11.1 Test of Ignition Safety System..........14
3.11.2 Test of Low Water Cut-off.................14
3.11.3 Test of Limit Controls........................14
3.11.4 Test of Low Gas Pressure Switch.....15
3.11.5 Test of High Gas Pressure Switch....15
3.12 Initial Adjustments...................................15
3.12.1A – Configuring the Local Controller...15
3.12.1B Optional Remote Control................20
3.12.2 Air Flow Adjustments........................20
3.12.3 Gas Pressure Adjustment.................21
4.0 OPERATION ............................................22
4.1 General......................................................22
4.1.1 Control Panel Front.............................22
4.2 Lighting and Shut-Down Procedures ........22
4.2.1 Lighting Procedures............................22
4.2.2 Normal Shut Down Procedures ..........23
4.2.3 Emergency Shut Off............................23
4.3 Typical Boiler Operating Conditions..........23
5.0 MAINTENANCE ......................................24
5.1 Maintenance and Inspection Schedule.....24
5.1.1 Daily....................................................24
5.1.2 Weekly ................................................24
5.1.3 Monthly (During Operation).................24
5.1.4 Semi-Annually.....................................24
5.1.5 Annually ..............................................25
5.2 Cleaning the Burner ..................................25

Modu-Fire® Gas-Fired Boiler Table of Contents
5.3 Removing the Exchanger .........................26
5.4 After All Repairs or Maintenance..............26
5.5 Sequence of Operation..............................27
5.5.1 Standard Modulating ..........................27
5.5.2 IRI Modulating ....................................28
5.6 Troubleshooting........................................29
6.0 PARTS/TECHNICAL SUPPORT..............31
6.1 Schematic Diagrams..................................31
Standard Unit - Local Control - Logic Diagram32
Standard Unit - Remote Control - Logic
Diagram..................................................33
Standard Unit - Local & Remote Control -
Logic Diagram........................................34
Standard Unit - Local & Remote Control w
Options - Logic Diagram........................35
IRI Unit - Local Control - Logic Diagram.......36
IRI Unit - Remote Control - Logic Diagram...37
IRI Unit - Local & Remote Control - Logic
Diagram..................................................38
IRI Unit - Local & Remote Control w Options -
Logic Diagram ........................................39
Standard Unit – Panel Layout.......................40
IRI Unit – Panel Layout.................................41
6.2 Boiler Parts List.........................................42
6.2.1 Main Assembly....................................42
6.2.2 Control Panel ......................................43
6.2.3 Gas Trains...........................................45
6.2.4 Cabinet................................................49
7.0 LIMITED WARRANTY.............................50
Reorder No. 6020-V2WHPK
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241
WARNING!
It is essential to read, understand, and follow the
recommendations of this manual before installing,
operating, or servicing this equipment. Failure to do
so could result in fire or explosion and serious in-
jury, death, and/or property damage.
The same features which permit this boiler to
achieve high-efficiency performance make it unlike
most other boilers of this general size, so it is im-
portant to understand how this boiler operates.
Do not store or use gasoline or other flammable
vapors or liquids in the vicinity of this or any other
appliance.
WARNING!
Installation and service must be performed by a
qualified installer, service agency, or gas supplier.
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. Imme-
diately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions.
•If you cannot reach your gas supplier call the
fire department.

Modu-Fire® Gas-Fired Boiler Introduction/Safety
1
1.0 INTRODUCTION
The P-K MODU-FIRE®Gas Fired Boiler is a revo-
lutionary advance; Patterson-Kelley now combines
full-modulation burner control with our time-tested
modular hot water boiler design. The result is
“modular full-modulation”- Modu-Fire! This new
hybrid boiler combines the best of our earlier de-
signs with a new generation of burner and control
technology. You will achieve even higher part-load
efficiencies – but without the complexity you might
expect in this type of high performance boiler. High
performance made simple and dependable for years
of trouble-free operation.
This manual covers installation of the P-K MODU-
FIRE®Boiler Series 1000, 1500, and 2000. The
model numbers may be followed by a prefix or suf-
fix letter in some cases to indicate special features
or different options. While details may differ
slightly, basic operation is the same for all models.
Boilers are built to operate with natural gas or pro-
pane. Check the rating plate for the correct gas type
and flow rate.
The boiler is only a part of the complete heating
system. This boiler may be fully operational and yet
because of poor circulation, controls, or other oper-
ating characteristics, not deliver heat to the desired
location. Additional equipment such as temperature
sensors, pumps, flow switches, balancing valves and
check valves will be required for satisfactory opera-
tion of any system. Patterson-Kelley cannot be re-
sponsible for the design or operation of such sys-
tems and a qualified engineer or contractor must be
consulted.
2.0 SAFETY
2.1 GENERAL
The MODU-FIRE®gas-fired boiler must be:
•Installed in accordance with designs prepared
by qualified facility engineers including: struc-
tural, mechanical, electrical, and other applica-
ble disciplines.
•Operated and serviced in accordance with a
comprehensive safety program determined and
established by the customer. Do not attempt to
operate or service until such a program has been
established.
•Operated and serviced by qualified, factory-
trained personnel in accordance with all appli-
cable codes, laws, and regulations.
•The use of the term “factory-trained personnel”
throughout this manual indicates Patterson-
Kelley trained on this specific piece of equip-
ment.
2.2 TRAINING
Reorder No. 6020-V2WHPK
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241
It is essential to read, understand, and follow the
recommendations of this manual before installing,
operating, or servicing this equipment. Failure to do
so could result in serious injury, death, and/or prop-
erty damage.
Proper training is the best protection against acci-
dents. Operating and service personnel must be
thoroughly familiar with the basic construction of
the MODU-FIRE®boiler, the use and locations of
the controls, the operation of the boiler, adjustment
of its various mechanisms, and all applicable safety
precautions. If any of the provisions of this manual
are not fully and completely understood, contact the
Patterson-Kelley Sales Department.
2.3 SAFETY FEATURES
It is the responsibility of the customer to maintain
the safety features of this machine, such as: guards,
safety labels, safety controls, interlocks, lockout
devices, etc., in place and operable.

Modu-Fire® Gas-Fired Boiler Safety
2
2.4 SAFETY LABELS
NOTE
Make sure this union is
tight before closing cabinet
cover after servicing boiler.
Reorder No. 8032-02NHAK
c
1998 HCS, Inc. 800-748-0241
NOTE
Reorder No. 8032-01NHPK
c
When opening leak test valves,
always follow instructions in
operation and safety manual.
1998 HCS, Inc. 800-748-0241
Reorder No. 6020-V2WHPK
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241
!
WARNING
C 1998 HCS, Inc. 800-748-0241 Reorder No. 5025-V1WHPK
Follow lockout/tagout
procedure when
servicing this boiler.
Electrical hazard.
The safety labels shown above are affixed to your
boiler. Although the labels are of high quality, they
may become dislodged or unreadable over time.
Contact Patterson-Kelley for replacement labels.
2.5 SAFETY PRECAUTIONS
Provide a suitable location for the boiler, away from
normal personnel traffic, with adequate working
space, adequate clearances, proper ventilation and
lighting, with a structure sufficiently strong and
rigid to support the weight of the boiler, all piping,
and accessories.
2.5.1 Electrical Hazards
!
WARNING
C 1998 HCS, Inc. 800-748-0241 Reorder No. 5025-V1WHPK
Follow lockout/tagout
procedure when
servicing this boiler.
Electrical hazard.
•Shock hazard! Properly lockout/tagout the elec-
trical service and all other energy sources before
working on or near the machine.
•Shock hazard! Boiler is not rated for wash-
down service.
2.5.2 Burn, Fire, and Explosion Hazards
General Warning
Hot Surface
Reorder No. 6020-V2WHPK
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241
NOTE
Make sure this union is
tight before closing cabinet
cover after servicing boiler.
Reorder No. 8032-02NHAK
c
1998 HCS, Inc. 800-748-0241
NOTE
Reorder No. 8032-01NHPK
c
When opening leak test valves,
always follow instructions in
operation and safety manual.
1998 HCS, Inc. 800-748-0241
•Burn, fire, and explosion hazards! Installation
must be in strict conformance to all applicable
codes and standards including NFPA 54, ANSI
Z223.1 and CAN/CGA B.149. Install all re-
quired ventlines for gas devices. Refer to Sec-
tion 3.7.2.
•Hazard from incorrect fuels! Possible fire, ex-
plosion, overheating, and damage. Do not use
any fuels except the design fuel for the unit.
•Overfire hazards! High pressure in gas or pro-
pane supply could result in overfiring of other
devices supplied from the same source.
•Fire and explosion hazards! Close the main gas
shutoff before servicing boiler.

Modu-Fire® Gas-Fired Boiler Safety
3
•Fire and explosion hazards! Do not store or use
gasoline or other flammable vapors or liquids in
the vicinity of this or any other gas fired appli-
ance.
•Burn hazard! Possible hot surfaces. Do not
touch gas vent during firing operation. Use only
factory recommended vent components.
•Burn hazard! Hot fluids. Use caution when
servicing or draining boiler.
•Fire and explosion hazards! Use caution when
servicing burner. Propane (LPG) is heavier than
air and may linger in the combustion chamber,
vent lines, or elsewhere.
•Gas leak hazard! Make sure all connections to
main burner are tight when reassembling the
burner. These connections cannot be tested af-
ter the burner is assembled.
•Gas leak hazard! All threaded gas connections
must be made using a pipe compound that is re-
sistant to liquefied petroleum. Do not use Tef-
lon™tape on threaded gas piping.
•Gas leak hazard! Check entire gas train for
leaks after installation. If there is a smell of gas,
shut down the boiler and obtain immediate as-
sistance from factory-trained personnel and/or
your local fire department.
•Overfire hazard! Possible fire and explosion
from excess gas pressure. Make sure that gas
inlet pressure does not exceed 14 inches w.c. to
the regulator.
•Overfire hazard! Possible fire and explosion.
Possible malfunction of regulators and/or mo-
torized gas valves. Maintain all gas train com-
ponents in good condition. Do not alter wiring
connections. Annual inspection by factory-
trained personnel for proper set-up and opera-
tion is recommended.
•Overfire and underfire hazards! Possible fire,
explosion, overheating, and component failure.
Do not attempt to adjust firing rate of the boiler.
The firing rate must be adjusted only by fac-
tory-trained personnel.
2.5.3 Crush Hazards
General Warning
•Lifting hazards! Use properly rated lifting
equipment to lift and position the boiler. The
load is unbalanced. Test balance before lifting 3
ft. above the floor. Do not allow personnel be-
neath the lifted load. Refer to approximate
weights in the table below:
Boiler Size Weight in Pounds
1,000,000 Btu 595
1,500,000 Btu 990
2,000,000 Btu 1,025
•Bump hazard from overhead piping. Install pip-
ing with adequate vertical clearance.
2.5.4 Chemical Hazards
General Warning
•Environmental hazard! The motorized gas
valves may contain hydraulic oil. Use safe pro-
cedures for the disposal of all lubricants.
•Chemical hazards from cleaning products. Use
caution when cleaning the system. The use of
professional assistance is recommended. Use
safe procedures for the disposal of all cleaning
solutions.

Modu-Fire® Gas-Fired Boiler Safety
4
2.5.5 Pressure Hazards
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241
•Pressure hazard! Hot fluids. Install isolation
valves on boiler water inlet and outlet. Make
sure isolation valves are closed before servicing
boiler.
•Pressure hazard! Hot fluids. Annually test
safety relief valve for proper operation. Do not
operate boiler with faulty relief valve.
2.5.6 Slip, Fall Hazards
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241
•Tripping hazard! Do not install piping on floor
surfaces. Maintain clear path around boiler.
•Slip and fall hazard! Use drip pan to catch wa-
ter while draining the boiler. Maintain dry floor
surfaces.
•Slip and fall hazard! Do not locate intake or
exhaust terminations directly above a walkway;
dripping of condensation can cause icing of the
walking surface.

Modu-Fire® Gas-Fired Boiler Installation
5
3.0 INSTALLATION
3.1 RECEIVING AND STORAGE
3.1.1 Initial Inspection
Upon receiving the boiler, inspect it for signs of ship-
ping damage. Pay particular attention to the control
panel on the top of the boiler and the components
mounted on the back, which may show damage from
mishandling.
The exterior cabinet must be reasonably air-tight for
the burner to operate correctly. Leaks caused by dents
in the sheet metal or panels out of position may cause
the limit controls to show Low Air. Check to be sure
that the mixer core in the top burner is centered and
has not moved in shipment; (see Section 5.2, "Clean-
ing the Burner" for proper location). Verify that the
total number of pieces shown on the packing slip
agrees with those actually received.
Important: Note any damage or shortage on the
freight bill and immediately notify the carrier. File
all claims for shortage or damage with the carrier.
3.1.2 Storage Prior to Installation
If the boiler is not installed immediately, it must be
stored in a location adequately protected from the
weather, preferably indoors. If this is not possible,
then it should remain in the shipping container and be
covered by a tarpaulin or other waterproof covering.
Note: Controls and other equipment that are damaged
or fail due to weather exposure are not covered by
warranty.
3.2 COMPLIANCE WITH CODES
The P-K MODU-FIRE®Boiler with standard compo-
nents and many options complies with American Na-
tional Standard/CSA Standard ANSI Z21.13/CSA 4.9,
latest edition, Gas-Fired Low Pressure Steam and Hot
Water Boilers. The heat exchanger is constructed and
stamped in accordance with ASME Boiler and Pres-
sure Vessel Code, Section IV for 160 psig maximum
operating pressure and/or 250º F maximum operating
temperature. Other codes or approvals which apply
will be labeled on the boiler.
Installation of the boiler must conform to all the re-
quirements of all national, state and local codes estab-
lished by the authorities having jurisdiction or, in the
absence of such requirements, in the U.S. to the Na-
tional Fuel Gas Code, ANSI Z223.1/NFPA 54, latest
edition. In Canada, the equipment shall be installed in
accordance with the current Installation Code for Gas
Burning Appliances and Equipment, CAN/CGA-
B.149, and applicable Provincial Regulations for the
class, which should be carefully followed in all cases.
Authorities having jurisdiction should be consulted
before installations are made.
Where required by local codes, the installation must
conform to American Society of Mechanical Engi-
neers Safety Code for Controls and Safety Devices for
Automatically Fired Boilers (ASME CSD-1).
In the Commonwealth of Massachusetts (a) this unit
must be installed by a licensed pipe fitter / plumber,
(b) field installed gas cocks must be "T" handle type,
and (c) piping of condensate shall conform with the
State Plumbing Code.
3.3 SETUP
3.3.1 Foundation
Provide a firm, level foundation, preferably of con-
crete.
Note: The boiler may be installed on a combustible
floor; however, the boiler must never be installed on
carpeting.
3.3.2 Placement
The boiler must be level to function properly. To as-
sist in leveling the boiler, the four (4) leg bolts (1/2"-
NC) holding the boiler to the shipping skid must be
reinstalled in the threaded legs on the bottom. The
adjustable legs are also necessary to provide adequate
floor clearance and prevent distortion on the cabinet,
(twisting, etc.) in addition to leveling.

Modu-Fire® Gas-Fired Boiler Installation
6
Adjustable Legs for Leveling and Floor Clearance
3.3.3 Clearances
If the boiler is to be installed near combustible sur-
faces, the minimum clearances shown in the table be-
low must be maintained.
Failure to provide for the service access clearances,
even with non-combustible surfaces, may cause future
problems servicing the boiler.
The boiler must be installed in a space large in com-
parison to the boiler as described in Section 6.3 of the
National Fuel Gas Code, ANSI Z223.1, latest edition.
AB
C
No pipes,
ducts, etc.
in this area.
DD
Minimum Clearances from Adjacent Walls, Ceiling, and
Obstructions
Dimensions (inches)
Type of Surface
A B C† D
Combustible Surfaces 30 24 30 24
Non-combustible Sur-
faces 30 24* 30 24**
† "C" dimension includes clearance to remove the
burner. Do not put pipes, ducts, etc. in this area above
the boiler.
* CSA minimum. Actual clearance depends upon
stacking requirements.
** Service access need be only on one side of a boiler
or row of boilers. Boilers may be installed immedi-
ately adjacent to each other. However, P-K recom-
mends this clearance between each boiler when there
is insufficient access at the rear to allow for service
and adjustment.
In Canada: The boilers are approved for installation
with zero clearance to combustible surfaces, but 24
inch service clearances are recommended.
3.4 ELECTRICAL CONNECTIONS
All field wiring connections for power and control are
in the rear service panel on the back of the boiler.
Low voltage and high voltage terminal strips are indi-
cated on the wiring diagram. The boiler power circuit
Back of
Boiler
Front of
Boiler

Modu-Fire® Gas-Fired Boiler Installation
7
is wired for 120 volts, single phase, 60 hertz. The total
operating amperage is indicated on the rating name-
plate. The 1000 series require less than 9 amps; the
1500 and 2000 series less than 12 amps. Before start-
ing the boiler, check to ensure that the proper voltage
and amperage are connected to the boiler.
An external electrical disconnect (not supplied with
the boiler) with adequate overload protection is re-
quired. The boiler must be grounded in accordance
with local codes or in the absence of such require-
ments, in the U.S. with National Electrical Codes,
ANSI/NFPA No. 70 latest edition and in Canada, wire
according to the current Canadian Electrical Code.
Note: A dedicated earth ground (green wire) is re-
quired to avoid nuisance shutdowns. Do not ground
through the conduit. It is also important that proper
polarity be maintained.
3.5 COMBUSTION AIR
Combustion air must be free from dust, lint, etc. The
presence of such materials in the air supplied to the
burner could cause nuisance "Low Air" shutdowns or
premature burner failure. The boiler should not be
operated during construction while the possibility of
drywall dust, demolition dust, etc. exists.
Provisions for combustion and ventilation air must be
in accordance with Section 5.3, Air for Combustion
and Ventilation, of the National Fuel Gas Code, ANSI
Z223.1, latest edition, or applicable provisions of the
local building codes. In Canada, combustion air open-
ings shall comply with CSA 4.9. The formula is "1 sq.
in. per 1,000 Btu/hr of gas input not less than 100 sq.
in." The location shall be "neither more than 18," nor
less than 6" above the floor level."
The boiler room shall be provided with two openings
to ensure adequate combustion air and proper ventila-
tion. One opening should be 6 to 12 inches above the
floor and the other 6 to 12 inches below the ceiling,
preferably on opposite walls. The size of each open-
ing is determined by whether air is taken from inside
or outside the building. In Canada, ventilation air
openings shall be at least 10% of the cross sectional
area required for combustion air, but not less than 10
square inches. It is to be located at the highest practi-
cal point communicating with outdoors.
If air is taken directly from outside the building, each
opening should have a net free area of 1 square inch
for each 4,000 Btu per hour of total boiler input. For
instance, 300 square inches (2-1/12 square feet) are
required for 1,200,000 Btu per hour input.
When air is taken from the outdoors through a vertical
duct, 1 square inch per 4,000 Btu per hour is required.
If a horizontal duct is used, 1 square inch per 2,000
Btu per hour is required, i.e., 600 square inches for
1,200,000 Btu per hour input.
If air is taken from another interior space, each open-
ing should have a net free area of 1 square inch for
each 1,000 Btu per hour of boiler input (1,200 square
inches for a 1,200,000 Btu per hour.)
WARNING!
Under no circumstances shall the boiler room ever be
under a negative pressure. Particular care should be
taken when exhaust fans, compressors, air-handling
units or other equipment may rob air from the boiler.
The combustion air supply must be completely free of
chemical fumes which may be corrosive when burned
in the boiler. Common chemicals which must be
avoided are fluorocarbons and other halogenated com-
pounds, most commonly present as refrigerants or sol-
vents, such as freon, trichlorethylene, perchlorethyl-
ene, chlorine, etc. These chemicals, when burned,
form acids which quickly attack the boiler tubes, tube
sheets, flue collectors and the boiler stack. The result
is improper combustion and premature boiler failure.
3.6 FLUE VENTING
This boiler requires a special vent system. Vent instal-
lations shall be in accordance with Part 7, Venting of
Equipment, of the National Fuel Gas Code, ANSI
Z223.1, CSA B149 code or applicable provisions of
the local building codes.
This boiler is Category II as it is defined in ANSI
Z21.13/CSA 4.9 latest edition. The vent material must
be listed Category II Vent pipe (316L or AL-29 4C
Stainless). Under no circumstances shall a Category I
material (e.g. B-vent) be used.

Modu-Fire® Gas-Fired Boiler Installation
8
WARNING!
This boiler should not be installed with an automatic
damper on the flue. Damper failure could create an
explosion hazard.
In Canada, the boiler is certified for installation with a
“Power Venter” by the Canadian Gas Association
when installed with the “listed accessories.” Consult
your local distributor for information on proper selec-
tion.
The venting system and the horizontal portions of the
venting system shall be supported to prevent sagging.
Consult your local vent supplier for correct vent sizing
and structural support requirements. Vent diameter is
dictated by the length and height of horizontal and ver-
tical portions of the vent installation and the materials
of construction. It is not necessarily the same size as
the boiler connection. Correct sizing should be based
on High fire input at a nominal -.04" w.c. draft pres-
sure at the boiler outlet with a gross stack temp of 325º
F and CO2ratings at 7.5%.
3.6.1 Vent Elbows
The first turn from horizontal to vertical should be
made with a 135° boot tee. A tee cover with a conden-
sate drain shall be provided at the bottom of the boot
tee. The condensate drain must be routed to a sewer
drain trap or pump in accordance with local codes.
Refer to diagram under Vent Elbows.
3.6.2 Barometric Damper
This boiler is certified for operation without a baro-
metric damper. P-K does not recommend the use of
one.
3.6.3 Automatic Vent Damper
WARNING!
This equipment, as manufactured, MUST NOT be
used with an automatic vent damper.
3.6.4 Flue Connection
The connection from the boiler to the vent should be
as direct as possible and the upward slope of any hori-
zontal breaching should be at least 1/4 inch per linear
foot. This boiler should not be connected into any por-
tion of a mechanical draft system operating under
positive pressure. Provisions must be made for sup-
ports to prevent contact of the vent with combustible
surfaces.
Note: Make sure that the weight of the vent is not
supported by the boiler vent collar. The collar is not
designed to support the weight of the vent. Structural
support and spacing from combustible surfaces must
be in accordance with the vent manufacturer's re-
quirements.
3.6.5 Vent Termination
The minimum vent height above the flue outlet must
be five (5) feet and the vent should extend at least
three (3) feet above the roof / snowline, or at least two
(2) feet above the highest part of any structure within
ten (10) feet of the vent.
6' min.
Pitch toward
boiler 1/4" per
foot minimum.
Boot Tee /135º
Tee
Trap Loop
3" min.
To sewer trap or
condensate drain.
Condensate Line

Modu-Fire® Gas-Fired Boiler Installation
9
Vent Termination
The vent must be provided with a weather cap of ap-
proved design and adequate capacity.
3.6.6 Removing an Existing Boiler
(from a common venting system)
When an existing boiler is removed from a common
venting system, the common venting system is likely
to be too large for proper venting of the appliances
remaining connected to it.
At the time of removal of an existing boiler, while the
other appliances remaining connected to the common
venting system are not in operation, the following
steps should be followed with each appliance remain-
ing connected to the common venting system placed in
operation:
1. Seal any unused openings in the common venting
system.
2. Visually inspect the venting system for proper size
and horizontal pitch and determine that there is no
blockage or restriction, leakage, corrosion or other
deficiency which could cause an unsafe condition.
3. Insofar as is practical, close all building doors and
windows and all doors between the space in which
the appliances remaining connected to the com-
mon venting system are located and other spaces
of the building. Turn on clothes dryers and any
appliances 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 ex-
haust fan. Close fireplace dampers.
4. Place the appliance being inspected in operation.
Follow the lighting instructions. Adjust the ther-
mostat so that the appliance will operate continu-
ously.
5. Test for spillage at the draft hood relief opening
after 5 minutes of main burner operation. Use the
flame of a match or candle or smoke from a ciga-
rette, cigar or pipe.
6. After it has been determined that each appliance
remaining connected to the common venting sys-
tem 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.
Any improper operation of the common venting sys-
tem should be corrected so the installation conforms
with the National Fuel Gas Code, ANSI Z223.1.
When resizing any portion of the common venting sys-
tem, the common venting system should be resized to
approach the minimum size as determined using the
appropriate tables in Part II in the National Fuel Gas
Code, ANSI Z223.1.
3.7 GAS PIPING
Before making the gas hook-up, make sure the boiler
is being supplied with the type of fuel shown on the
boiler nameplate.
The boiler shall be installed such that the gas ignition
system components are protected from water (drip-
ping, spraying, rain, etc.) during appliance operation
and service (circulator replacement, control replace-
ment, etc.)
The gas train components are designed to handle a
maximum inlet pressure of 14 inches water column
(1/2 psig.). If the available gas pressure exceeds 14
inch w.c., a suitable additional intermediate gas pres-
sure regulator of the "lock up" type must be provided
to reduce the pressure to less than 14 inch w.c.
Correct Listed
Termination Incorrect
Termination
(
too restrictive
)

Modu-Fire® Gas-Fired Boiler Installation
10
Gas Piping
Note: Install a sediment trap (drip leg) and a union
connection ahead of the primary manual shutoff valve
on the boiler. Gas piping should be installed in accor-
dance with National Fuel Gas Code, ANSI Z223.1,
latest edition, and any other local codes which may
apply; in Canada see CAN/CGA-B 149.
Note: See chart below for required pipe size, based on
overall length of pipe from meter plus equivalent
length of all fittings. Approximate sizing may be based
on 1 cubic foot of natural gas per 1,000 Btu per hour
input, i.e., 900,000 Btu per hour requires about 900
cubic feet per hour. (See Typical Boiler Operating
Conditions, Section 4.3, for more information.)
WARNING!
All threaded connections must be made using a pipe
compound that is resistant to the action of liquefied
petroleum gases. Do not use Teflon tape on gas line
threads.
Pipe Capacity for Natural Gas
Equivalent Pipe Length Maximum Capacity in Cubic Feet of Natural Gas per Hour
Pressure Drop of 0.5 inch Water Column/Equivalent Length of
Pipe (in feet)
Nominal
Iron
Pipe
Size
(Inches)
Internal
Diameter
(Inches) 90º Ell
(Feet)
Tee
(Feet) 20 40 60 80 100 150 200
1-1/4 1.380 3.45 6.9 950
1-1/2 1.610 4.02 8.04 1,460 990 810
2 2.067 5.17 10.3 2,750 1,900 1,520 1,300 1,150 950 800
2-1/2 2.469 6.16 12.3 4,350 3,000 2,400 2,050 1,850 1,500 1,280
3 3.068 7.67 15.3 7,700 5,300 4,300 3,700 3,250 2,650 2,280
4 4.026 10.1 20.2 15,800 10,900 8,800 7,500 6,700 5,500 4,600
By Installer
Remote Gas
Shutoff (not
supplied)
Drip Leg
Union
Shutoff (on
boiler)
Gas Meter (not
supplied)

Modu-Fire® Gas-Fired Boiler Installation
11
3.7.1 Gas Supply Piping by Installer
The boiler and all gas piping connections should be
pressure-tested and must be checked for leaks be-
fore being placed into service. Test with com-
pressed air or inert gas if possible.
The boiler must be disconnected at the boiler man-
ual shut-off valve (located at the end of the supplied
gas train) from the gas supply piping system during
any pressure testing of the system at pressures in
excess of 1/2 psig (14 inch w.c.).
During any pressure testing of the gas supply piping
system at pressures equal to or less than 1/2 psig (14
inch w.c.), the boiler should be isolated from the gas
supply piping system by closing the manual shut-
off.
Some leak test solutions, including soap and water,
may cause corrosion. These solutions should be
rinsed-off with water after testing.
3.7.2 Gas Bleeds and Vents by Installer
If your unit is equipped with a diaphragm gas valve,
the bleed vents on the diaphragm gas valves have
been factory-piped to terminate at the burner, as re-
quired by ANSI Z21.13. This feature provides com-
bustion of any gas which leaks past a ruptured dia-
phragm during operation. Gas vents to outdoor air
must be provided for the main pressure regulator.
The pilot regulator is equipped with a vent limiting
device and does not require external venting!
•When installing per ASME CSD-1, discon-
nect factory piped bleed vents and vent the
diaphragm gas valves to outdoor air (field
piping.)
If a N.O. (normally open) vent valve is provided, it
must be vented independently of any other bleeds
and vents. Discharge of vent lines should be pro-
tected by an insect screen.
The air gas ratio control valve is equipped with a
“reference chamber vent filter” which does not re-
quire any additional venting. This connection is
labeled COMBUSTION / ATMOSPHERE.
If local conditions require venting to outdoors, the
vent line connection must be piped by the installer
in accordance with the National Fuel Gas Code
(NFPA 54), ANSI Z223.1, which states:
“In the case of vents leading outdoors, means shall
be employed to prevent water from entering this
piping and also to prevent blockage of vents by in-
sects and foreign matter.”
The National Fuel Gas Code Handbook goes on to
say that “Insects, insect nests, ice, or freezing rain
can block outdoor vents....”
The pilot regulator is equipped with a vent limiting
device and does not require external venting!
Gas Vents by Installer
Note: Provide a drip leg in all vent/bleed lines.
All vent lines should be pitched up at all times to
prevent building a trap into the vent line.
“Vent limiters” are NOT to be installed on this
boiler.
The air gas ratio control valve is equipped with a
“reference chamber vent filter” which does not re-
quire any additional venting.
3.8 BOILER WATER PIPING
3.8.1 Piping Design
Water Flow in System
Ideal operation of the P-K MODU-FIRE®Boiler
would consist of a 20º F temperature differential
across the heat exchanger at High fire. Insufficient
flow may result in excessive short cycling of the
boiler and eventual damage or premature failure of
the equipment.
Minimum Return Water Temperature should be
greater than 130º F to avoid problems of condensa-
tion on the outside of the heat exchanger or in the
flue passages.
Proper flow rates and return water temperature may
be achieved through a combination of primary and
secondary flow loops. Multiple zones and pumps
may result in different flow rates at different times.

Modu-Fire® Gas-Fired Boiler Installation
12
Consideration must be given to all possible condi-
tions and their consequences.
Piping With Refrigeration Machines
When used with a refrigeration system, the boiler
shall be installed so that chilled medium is piped in
parallel with the boiler. Valves should be installed
to prevent chilled water from entering the boiler
when the system is operated in the cooling mode.
Piping With Air Handling Units
The boiler piping system of a hot water heating
boiler connected to heating coils located in air han-
dling units, where they may be exposed to refriger-
ated air circulation, must be equipped with flow
control valves or other automatic means to prevent
gravity circulation of the boiler water during the
cooling cycle.
3.8.2 Boiler Inlet and Outlet Connections
Boiler Inlet and Outlet Connections
Make water connections as the application warrants,
or at a minimum, as shown, but always in compli-
ance with the local requirements.
Note: Pipe unions and isolating valves must be
installed in both water connections for ease of
service.
The bottom connection to the boiler is the INLET
and must be used for the return from the system.
The top connection to the boiler is the OUTLET and
must be connected as the supply to the system.
Piping must be installed such that no piping stresses
are transmitted to the boiler. The boiler should not
be used as a pipe anchor.
3.8.3 Boiler Water Piping by Installer
Strainer
To avoid possible contamination of the boiler with
dirt, rust or sediment from the system, a strainer
near the boiler inlet is strongly recommended. Even
new systems may contain sufficient foreign material
to eventually reduce the performance of the heat
exchanger. Adequate circulation of good clean wa-
ter is essential to maximum efficiency and long life
of the boiler.
Relief Valve and Piping
Each boiler is supplied with a pressure-relief valve
sized in accordance with ASME requirements. The
relief valve should be piped to a suitable floor drain.
Reducing couplings or other restrictions are not
permitted in the discharge line.
Low Water Cut-off
The boiler is furnished with a flow-switch-type low
water cut-off as required by Section IV ASME
Code; no field piping is required. If the flow switch
does not sense water flow, the boiler will shut down
and a red indicator will be illuminated on the control
panel. This flow switch only proves that flow is
present. It does not prove adequate flow as required
by this boiler.
Installation of an external low water cutoff or man-
ual reset low-water switch may be required by cer-
tain codes or in certain installations. Consult your
local code for details.
Boiler
Drain
Isolating
Valve
Relief Valve
Drain Union
Isolating
Valve
Outlet (to
system)
Inlet (from
system)
Strainer Isolating
Valve

Modu-Fire® Gas-Fired Boiler Installation
13
WARNING!
Never install a valve that can isolate the low water
cutoff from the boiler.
Drain Valve and Piping
The boiler is not provided with external drain con-
nections. A drain valve should be installed near the
inlet (system return) connection to the boiler and
piped to a suitable floor drain. The boiler can be
completely drained through the bottom header by
removing the flush plug in the bottom end plate.
This plug may also be used to flush accumulated
sediment from the bottom of the boiler.
3.8.4 Flushing and Filling
Flushing the System
Before filling the boiler, flush the system to remove
the debris. Clean and flush old piping thoroughly
before installing the boiler as recommended by your
water conditioning or chemical treatment supplier.
Under no circumstances should the hydronic system
be flushed while the boiler is attached to the system
since the debris or corrosion products could accu-
mulate in the boiler and plug the boiler heat ex-
changer.
If the piping system attached to this unit will be
chemically cleaned, the boiler must be disconnected
from the system and a bypass installed so that the
chemical cleaning solution does not circulate
through the boiler.
Filling
To be sure that the boiler is not air-bound, open the
pressure-relief valve located at the rear of the boiler.
Leave the relief valve open until a steady flow of
water is observed. Close the valve and finish filling
the system.
3.8.5 Water Quality
The boiler is designed to operate in a closed-loop
system. As such, the system should be tight and not
require make-up water. A high percentage of un-
treated make-up water can cause premature failure
due to buildup of scale. Such failure is not covered
by warranty.
Scale can also reduce efficiency. For example, a
scale thickness of 1/16" will result in a 12.5% loss
of efficiency.
The water quality should be within the guidelines
established by the American Boiler Manufacturers
Association, as follows:
•Total solids: 2,500 ppm
•Total alkalinity: 500 ppm
•Total hardness: 150 ppm
The amount of oils, fats, grease, and other organic
matter should be limited to 10 ppm.
Consult your water conditioning or chemical treat-
ment supplier for analysis and recommendations.
If antifreeze is to be used in the system, the cus-
tomer should perform a hazard analysis to determine
the use and disposal of the antifreeze.
3.9 BURNER AND IGNITION SYSTEM
3.9.1 Inspection
Inspect the burners to be sure nothing was damaged
or knocked loose during shipment. Make sure that
the mixer core in the top of the burner is centered in
the burner head; (see burner photo in section on
"Cleaning the Burner" Section 5.2). Inspect the pi-
lot line, main gas train and ignition electrode to be
sure they were not damaged during shipment or in-
stallation. Check to see that the pilot is securely
attached and that it is properly positioned to ignite
the main burner.
3.10 PRE-START CHECK LIST
Before attempting to start the boiler, make sure the
following items have been completed.
1. Flue gas from the boiler is properly vented.

Modu-Fire® Gas-Fired Boiler Installation
14
2. Gas connection has been made, pressure tested
for leakage, and the line purged of air. Make
sure all required bleeds and vents have been in-
stalled.
3. Water connections are complete, and the boiler
and system have been filled and purged of air.
4. The boiler must be connected to a 120 volt / 60
Hz power source with proper polarity and dedi-
cated machinery ground. Provide a disconnect
having adequate overload protection.
5. Combustion air openings are not obstructed in
any way and have adequate capacity. (See Sec-
tion 3.5)
6. The boiler is placed the proper distance from
any combustible walls or substances, in accor-
dance with Section 3.3.3.
7. Relief valves have been properly piped to floor
drains.
3.11 SAFETY CHECKS
The following checks of safety systems must be
made before putting the boiler into normal opera-
tion.
Before firing the boiler refer to Sections 4.1 and 4.2
for information on the use of the controls, lighting,
and shut-down procedures.
WARNING!
Never attempt to operate a boiler that has failed to
pass all the safety checks described below.
WARNING!
After checking controls by manual adjustment, make
sure they are always reset to their proper settings.
3.11.1 Test of Ignition Safety System
Test the ignition system safety shutoff as follows:
1. Close the gas cock which is downstream from
the two safety shut off valves (in the vertical
line).
2. With the main gas cock (inlet manual gas valve)
open and the pilot gas cock open, the burner
should be cycled on. After all the safety limits
on gas pressure, water flow and temperature are
satisfied, the blower will run and pre-purge the
boiler.
3. When air flow is established, the ignition trans-
former and pilot will operate. Both functions
will be indicated by separate indicator lights on
the flame safeguard.
4. If a satisfactory pilot is established, the spark
will terminate and the pilot will remain on,
alone, for 10 seconds.
5. After 10 seconds, the "Main” light on the flame
safeguard will go on; gas will not flow since the
downstream cock is closed. The "Pilot" will
remain on, along with the "Main Gas", for an-
other 10 - 15 seconds and then go out. Since the
gas cock is closed, at this point there will be no
main flame signal and the flame safeguard pro-
grammer will assume a “Flame Failure” and go
to a "lockout" mode. Lockout will require man-
ual reset of the flame safeguard.
After completing this test, turn off the boiler and
reopen the downstream gas cock.
3.11.2 Test of Low Water Cut-off
The boiler is furnished with a flow-switch-type low
water cutoff in the outlet nozzle. Test as follows:
Operation of the switch can be checked by first turn-
ing the boiler off and then turning the system pump
off, stopping water flow in the system. After turn-
ing off the pump, turn the boiler back on. It should
not operate, and a red indicator for "Low Water" or
"Water Flow" should be illuminated. Do not shut
the pump off while the boiler is operating.
Perform appropriate tests on any external probe-type
low water cutoff.
3.11.3 Test of Limit Controls
Fire the boiler and test the high limit control as fol-
lows:
With the main burner operating, turn down the tem-
perature setting on the "high-limit" thermostat until

Modu-Fire® Gas-Fired Boiler Installation
15
the main burner shuts off (the green "Heat" indicator
will go out). The high-limit switch must be manu-
ally reset after testing. This same check should also
be made for the "Operating Temperature" control.
After completion of these tests, readjust thermostats
to desired operating temperature and set high-limit
temperature, typically 20º F above operating tem-
perature.
3.11.4 Test of Low Gas Pressure Switch
Gas Pressure Switch
The boiler is furnished with a low gas pressure
switch. The operation of this switch must be
checked by slowly closing the main gas cock while
the burner is operating. The switch should shut
down the main burner. When the gas pressure
switch opens, the "Gas Press." indicator will light.
Upon reopening the main gas cock, the "Gas Press."
indicator should remain on until the low gas pres-
sure switch is manually reset.
3.11.5 Test of High Gas Pressure Switch
The correct setting of the high gas pressure switch is
essential for proper operation of the boiler. This
switch is set by the factory at 4.0” w.c. and must not
be changed.
This switch must be checked by factory-trained per-
sonnel.
3.12 INITIAL ADJUSTMENTS
3.12.1A – Configuring the Local Controller
(Applies to models furnished with programmable
temperature control.)
Operating Modes:
Internal Setpoint
Night Setback (Alternate Setpoint)
Outdoor Air Reset
Analog Input Setpoint (See Section 3.12.1B.)
Analog Input Direct Drive (Multiple boiler
Controls)
Definitions:
SP1- Setpoint 1:...................This is the primary
setpoint of the boiler.
SP2- Setpoint 2 :...................An alternate setpoint.
Available through the
alternate setpoint con-
tact closure.
dSP- Differential Setpoint : ..An alternate setpoint
differential from SP1.
Available through the
alternate setpoint con-
tact closure.
tA- Air temperature: ............Measurement of out-
side air temperature.
SP.E- External Setpoint:.......Measurement of the
external setpoint.
HyS1:....................................Low temperature dif-
ferential.
HyS3:....................................High temperature dif-
ferential.
Internal Setpoint
The boiler water outlet temperature is controlled to
SP1 (setpoint 1) and the boiler modulates to main-
tain SP1 subject to the upper and lower temperature
differentials and the upper and lower setpoint limit.
Manual Reset

Modu-Fire® Gas-Fired Boiler Installation
16
For example, assume the following settings:
Item Display Value
Setpoint 1 SP1 160
Low Temp Differential HyS1 -5
High Temp Differential HyS3 12
Low Temp Setpoint SPL 150
High Temp Setpoint SPH 195
The boiler will modulate to try to maintain 160 o F.
If the temperature increases to 172 o F which is Set-
point 1 (SP1) 160 + High Temp Differential (HyS3)
12, it will shut off. Once it shuts off, it will not re-
start until the temperature drops to 155 o F which is
Setpoint 1 (SP1) 160 + Low Temp Differential
(Hys1) -5. The Low Temp Setpoint (SPL) prevents
the operator from setting Setpoint 1 (SP1) lower
than Low Temp Setpoint (SPL) 150. The High
Temp Setpoint (SPH) prevents the operator from
setting Setpoint 1 (SP1) higher than the High Temp
Setpoint (SPH) 195.
Alternate Setpoint
The control must be configured for night setback.
(See the configuration menu.) When the Alternate
Setpoint contact is closed the boiler switches to its
alternate setpoint.
The alternate setpoint can be determined by several
different values. It can be a fixed alternate setpoint
SP2. It can be a fixed differential from SP1 called
dsP. dsP will “offset” the main setpoint SP1 by the
value of dsP. dsP can be positive or negative.
The Alternate Setpoint can also be determined by an
external analog source such as a 4-20 mA signal.
Outdoor Air Reset
The control must be configured for outdoor air reset.
(See the configuration menu.)
The setpoint of the boiler is controlled by an out-
door temperature sensor. As the outdoor tempera-
ture falls the setpoint of the boiler is increased.
The boiler modulates to maintain this setpoint. The
boiler functions as indicated in internal setpoint;
however, SP1 is determined by the outdoor air tem-
perature.
The setpoint SP1 is reset using a linear relationship
with outdoor air temperature. As the outdoor air
temperature drops the setpoint SP1 is increased a
proportional amount. This increase is determined
by the Heating Slope H. (See Table 1 at the end of
this section.) For example if H is set at 1 then for
every degree the outdoor air temp drops, the set-
point SP1 will increase 1 degree.
This heating curve has a reference temperature of
68°. This reference can be offset using the Parallel
shift parameter P. (See Table 1 at the end of this
section.) If P is set to 0 the setpoint SP1 will be 68°
when the outdoor temp is 68°. If P is set to 10, the
setpoint SP1 will be 78° when the outdoor temp is
68°. The minimum setpoint of the boiler is limited
by the control. In the above example the actual set-
point SP1 of the boiler will not go below 150°.
Analog Input Setpoint
The control must be configured for external set-
point. (See the configuration menu.)
The setpoint of the boiler is controlled by an exter-
nal signal. The boiler functions as described with
the internal setpoint, using the value determined by
the external analog signal.

Modu-Fire® Gas-Fired Boiler Installation
17
Analog Input Direct Drive
The firing rate of the boiler is controlled by an ex-
ternal analog signal, usually from a multiple boiler
control. The boiler turns on and off as directed by
the external control.
An operating limit control ensures that the boiler
temperature does not exceed the set value.
Refer also to Section 3.12.1B.
Use of the Controller
The diagram shows the RWF40 after switching on
power. This condition is called the basic display.
The actual value and the currently active setpoint
are shown here. Manual operation, self-setting, and
the user, parameter, and configuration levels can be
activated from here.
Operation of the Control
The temperature control has three levels of cascad-
ing menus. They are:
USER level,
PARAMETER level, and the
CONFIGURATION level.
The following table indicates the menu options
available from each level. The options available
depend on the operating mode of the boiler.
User Level:
To access the User level from the basic display
press PGM.
Change the setpoint SP1 with or .
Change to setpoint SP2 or dSP with PGM.
Change the setpoint SP2 or dSP with or .
Return to the basic display with EXIT.
Manual Operation of the Boiler
The boiler firing rate can be controlled manually.
Manual Opera-
tion
EXIT But-
ton
Operating Limit Closed
Firing Rate Decreasing
Firing Rate Increasing
Alarm Relay
Energized
Increase
Value
Actual Value
Display (red)
Setpoint
Display
(green)
Decrease
Value
PROGRAM
Button