American Standard GRWF130A94A0A User manual

IMPORTANT — This Document is customer property and is to remain with this unit. Please
return to service information pack upon completion of work.
Direct Vent Gas Fired Water Boiler
with Cast Iron Heat Exchanger
© 2007 American Standard Inc. All Rights Reserved
INSTALLATION GUIDE
*GRWF130A94A0A
*May be “A” or “T”
ALL phases of this installation must comply with NATIONAL, STATE AND LOCAL CODES
18-CG02D1-4
CUS
®

18-CG02D1-4
2
1.0 Safety Considerations
IMPORTANT: Read this entire manual before
beginning installation procedures.
Read this manual carefully before attempting to
install, operate, or perform maintenance on this
boiler. Installation, service, and maintenance should
be performed by qualified technicians only.
NOTE: “Warnings” and “Cautions” appear at appro-
priate places in this manual. Read these carefully.
Your personal safety and the proper operation of
this heating product require that you follow them
carefully. The manufacturer assumes no liability for
installations or services performed by an indepen-
dent dealers.
Safety signal words are used to designate a degree
or level of seriousness associated with a particular
hazard. The signal words for safety markings are
WARNING and CAUTION.
▲
▲
WARNING
!
WARNING indicates a potentially hazardous situa-
tion which, if not avoided, could result in pro-
perty damage, death or serious injury.
▲
▲
CAUTION
!
CAUTION indicates a potentially hazardous situa-
tion which, if not avoided, may result in minor or
moderate injury. It is also used to alert against
unsafe practices and hazards involving only
property damage.
|
1.1 WARNINGS
▲
▲
WARNING
!
THE INFORMATION IN THIS GUIDE IS FOR USE
BY INDIVIDUALS HAVING ADEQUATE ELECTRI-
CAL AND MECHANICAL BACKGROUND NECES-
SARY TO INSTALL BOILER PRODUCTS. ANY
ATTEMPTS, BY UNQUALIFIED PERSONS, AT
PLUMBING, INSTALLING OR REPAIRING A
BOILER MAY RESULT IN PERSONAL INJURY
AND/OR PROPERTY DAMAGE. THE MANUFAC-
TURER OR SELLER CANNOT BE RESPONSIBLE
FOR THE INTERPRETATION OF THIS INFORMA-
TION, NOR CAN IT ASSUME ANY LIABILITY IN
CONNECTION WITH ITS USE.
▲
▲
WARNING
!
ELECTRICAL HAZARD
DISCONNECT POWER BEFORE INSTALLING OR
SERVICING THE BOILER.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
WARNING
!
FIRE OR EXPLOSION HAZARD.
TURN OFF MAIN GAS VALVE BEFORE INSTAL-
LING, PERFORMING MAINTENANCE OR SERVI-
CING A BOILER.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
WARNING
!
EXPLOSION HAZARD
PROPANE GAS IS HEAVIER THAN AIR AND MAY
COLLECT IN ANY LOW AREAS OR CONFINED
SPACES. IF THE GAS BOILER IS INSTALLED IN
A BASEMENT, AN EXCAVATED AREA OR A CON-
FINED SPACE, IT IS STRONGLY RECOMMENDED
TO CONTACT A GAS SUPPLIER TO INSTALL A
GAS DETECTING WARNING DEVICE IN CASE OF
A GAS LEAK.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
NOTE: The manufacturer of your boiler does not test any
detectors and makes no representations regarding any
brand or type of detector.
▲
▲
WARNING
!
EXPLOSION HAZARD
ODORANT FADE MAY MAKE THE GAS UNDE-
TECTABLE EXCEPT WITH A WARNING DEVICE.
IF THE GAS BOILER IS INSTALLED IN A BASE-
MENT, AN EXCAVATED AREA OR A CONFINED
SPACE, IT IS STRONGLY RECOMMENDED TO
CONTACT A GAS SUPPLIER TO INSTALL A GAS
DETECTING WARNING DEVICE IN CASE OF A
GAS LEAK.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
NOTE: The manufacturer of your boiler does not test any
detectors and makes no representations regarding any
brand or type of detector.
▲
▲
WARNING
!
FIRE HAZARD
DO NOT INSTALL THIS BOILER WHERE COMBU-
STIBLE PRODUCTS AND FLAMMABLE LIQUIDS
ARE STORED OR WHERE FLAMMABLE VAPORS
ARE PRESENT.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.

18-CG02D1-4
3
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation could result in carbon monoxide
poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation:
1. Seal any unused openings in the venting system.
2. Inspect the venting system for proper size and
horizontal pitch, as required in the National Fuel Gas
Code, ANSI Z223.1/NFPA 54 or the CAN/CGA B149
Installation Codes and these instructions. Determine
that there is no blockage or restriction, leakage,
corrosion and other deficiencies which could cause an
unsafe condition.
3. As far as practical, close all building doors and
windows and all doors between the space in which the
appliance(s) connected to the venting system are
located and other spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not
connected to the venting system. Turn on any exhaust
fans, such as range hoods and bathroom exhausts, so
they are operating at maximum speed. Do not operate
a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance
being inspected into operation. Adjust the thermostat
so appliance is operating continuously.
7. If improper venting is observed during any of the above
tests, the venting system must be corrected in
accordance with the National Fuel Gas Code,
ANSI Z221.1/NFPA 54 and/or CAN/CGA B149
Installation Codes.
8. After it has been determined that each appliance
connected to the venting system properly vents where
tested as outlined above, return doors, windows,
exhaust fans, fireplace dampers and any other gas-fired
burning appliance to their previous conditions of use.
▲WARNING
!
The following warning complies with State of California law, Proposition 65.
HAZARDOUS GASES!
EXPOSURE TO FUEL SUBSTANCES OR BY-PRODUCTS
OF INCOMPLETE FUEL COMBUSTION IS BELIEVED BY
THE STATE OF CALIFORNIA TO CAUSE CANCER, BIRTH
DEFECTS, OR OTHER REPRODUCTIVE HARM.
▲
WARNING
!
▲
▲
WARNING
!
BURN HAZARD
ALLOW BOILER TO COOL DOWN PRIOR TO SER-
VICING OR PERFORMING MAINTENANCE.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
WARNING
!
SAFETY HAZARD
DO NOT BYPASS SAFETY CONTROLS
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
WARNING
!
FIRE HAZARD
DO NOT INSTALL THIS BOILER DIRECTLY ON
CARPETING. FAILURE TO FOLLOW THIS WAR-
NING COULD RESULT IN SERIOUS INJURY,
DEATH, OR PROPERTY DAMAGE..
NOTE: THIS PRODUCT IS APPROVED FOR
INSTALLATION ON COMBUSTABLE FLOORING
MATERIALS EXCEPT FOR CARPET.
▲WARNING
!
SAFETY HAZARD
THESE BOILERS ARE NOT APPROVED OR
INTENDED FOR INSTALLATION IN MANUFAC-
TURED (MOBILE) HOUSING, TRAILERS, OR
RECREATIONAL VEHICLES.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
WARNING
!
DO NOT USE THIS UNIT IF ANY PART HAS BEEN
UNDER WATER. IMMEDIATELY CALL A QUALI-
FIED SERVICE TECHNICIAN TO INSPECT THE
BOILER AND TO REPLACE ANY PART OF THE
CONTROL SYSTEM AND ANY GAS CONTROL
WHICH HAS BEEN UNDER WATER.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
WARNING
!
HEAVY OBJECT HAZARD
A BOILER IS A HEAVY OBJECT. DO NOT
HANDLE OR WORK UNDER A BOILER WITHOUT
PROPERLY SECURING IT THROUGH SHORING,
BLOCKING OR CRIBBING. FOLLOW ALL STATE
AND FEDERAL CODES AND OSHA REGULA-
TIONS AND GUIDELINES FOR HANDLING THE
BOILER DURING INSTALLATION AND SERVI-
CING.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.

18-CG02D1-4
4
▲
WARNING
!
The following warning complies with State of California law, Proposition 65.
This product contains fiberglass wool insulation!
Fiberglass dust and ceramic fibers are believed by the
State of California to cause cancer through inhalation.
Glasswool fibers may also cause respiratory, skin, or
eye irritation.
PRECAUTIONARY MEASURES
●Avoid breathing fiberglass dust.
●Use a NIOSH approved dust/mist respirator.
●Avoid contact with the skin or eyes. Wear long-sleeved,
loose-fitting clothing, gloves, and eye protection.
●Wash clothes separately from other clothing: rinse
washer thoroughly.
●Operations such as sawing, blowing, tear-out, and
spraying may generate fiber concentrations requiring
additional respiratory protection. Use the appropriate
NIOSH approved respirator in these situations.
FIRST AID MEASURES
Eye Contact – Flush eyes with water to remove dust.
If symptoms persist, seek medical
attention.
Skin Contact – Wash affected areas gently with soap
and warm water after handling.
▲
▲
WARNING
!
If the information in this manual is not followed exactly,
a fire or explosion may result causing property
damage, personal injury or loss of life.
— Do not store or use gasoline or other flammable
vapors or liquids in the vicinity of this or any
other appliance.
— WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch;
do not use any phone in your building.
• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions.
• If you cannot reach your gas supplier,
call the fire department.
— DO NOT RELY ON SMELL ALONE TO DETECT
LEAKS. DUE TO VARIOUS FACTORS, YOU MAY
NOT BE ABLE TO SMELL FUEL GASES.
• U.L. recognized fuel gas and CO detectors are
recommended in all applications, and their
installation should be in accordance with the
manufacturer's recommendations and/or local
laws, rules, regulations, or customs.
— Installation and service must be performed by a
qualified installer, service agency or the gas
supplier.
1.2 CAUTIONS
▲
▲
CAUTION
!
Do NOT install the boiler in a corrosive or contaminated
atmosphere.
1.3 Notes
The following notes must be followed during the instal-
lation, servicing, and operation of this boiler:
1. NOTE: This device must only be used for the pur-
pose for which it is specially designed. This unit is
designed to heat water to a temperature below boiling
point at atmospheric pressure and must be connected to
a hydronic heating system and/or a water supply system
for domestic use, compatible with its performance, cha-
racteristics and its heating capacity. Any other use is
considered improper.
2. NOTE: These instructions do not cover all variations
in systems or provide for every possible contingency.
Should further information be desired or particular
problems arise which are not covered sufficiently by this
manual, contact your local distributor for assistance.
3. NOTE: Use only with the type of gas approved for
this boiler. Refer to the boiler rating plate.
4. NOTE: Install this boiler only in a location and posi-
tion as specified in “Locations and Clearances.”
5. NOTE: Provide adequate combustion and ventila-
tion air to the boiler space as specified in “Air for Com-
bustion and Ventilation.”
6. NOTE: Combustion products must be discharged
outdoors. Connect this boiler to an approved vent
system only as specified in the “Venting” section of this
guide.
7. NOTE: Never test for gas leaks with an open flame.
Use a commercially available soap solution made speci-
fically for the detection of leaks to check all connections,
as specified in “Gas Piping.”
8. NOTE: Always install the boiler to operate within
the boiler’s intended operating temperature range.
9. NOTE: The boiler is not to be used for temporary
heating of buildings or structures under construction.
10. NOTE: Wear appropriate gloves, arm sleeve pro-
tectors, and eye equipment when servicing or maintai-
ning this equipment.
11. NOTE: Verify system is leak free at startup.
During routine boiler maintenance check integrity of
system to be sure there are no leaks. A leak will result
in a continuous flow of make up water leading to pre-
mature heat exchanger failure. Minerals will build up
inside heat exchanger sections reducing performance
and cause section failure. The additional oxygen added
to the system from make up water speeds corrosion
inside the heat exchanger. Maintenance and cleaning
must be performed at least once every year.
NOTE: This product must be gas piped by a licen-
sed Plumber or Gas Fitter in the Commonwealth
of Massachusetts.

18-CG02D1-4
5
1.0 Safety considerations................................................................................. 2
1.1 Warnings.................................................................................................................2
1.2 Cautions..................................................................................................................4
1.3 Notes.......................................................................................................................4
2.0 Pre-Installation Information & Instructions............................................ 6
2.1 Parts Included........................................................................................................6
2.2 General Specifications ..........................................................................................7
2.3 Codes and Regulations ..........................................................................................8
2.4 Locations and Clearances......................................................................................8
2.5 Outline Drawings...................................................................................................9
3.0 Installation Instructions.......................................................................... 10
3.1 Moving and Uncrating the Boiler .......................................................................10
3.2 Setting Boiler .......................................................................................................11
3.3 Leveling Boiler .....................................................................................................11
3.4 Water Connections and Piping Systems .............................................................12
3.5 Combustion Air and Ventilation..........................................................................18
3.6 General Venting Instructions ..............................................................................20
3.7 Gas Connections...................................................................................................22
3.8 LP Gas Conversion...............................................................................................23
3.9 High Altitude Derate ...........................................................................................27
3.10 Lighting Instructions.........................................................................................27
3.11 Electrical Connections .......................................................................................28
3.12 Optional Manual Reset Water Temperature Limit Installation .....................29
3.13 Supply Water Thermostat (SWT) Settings above 180°F..................................34
4.0 Startup and Adjustments ....................................................................................35
4.1 Preliminary Inspections ......................................................................................35
4.2 Operating Information.........................................................................................37
5.0 Technical Data.......................................................................................... 39
5.1 Electrical Diagram...............................................................................................39
5.2 Schematic Diagram..............................................................................................40
5.3 Field Wiring Diagrams ........................................................................................41
Table of Contents
6.0 Appendices................................................................................................ 45
6.1 Appendix A - Venting Supplement ......................................................................45
6.2 Appendix B - Vent Terminations .........................................................................53

18-CG02D1-4
6
2.0 Pre-Installation Information & Instructions
Material in this shipment has been inspected at the factory and released to the transportation
agency without known damage. Inspect exterior of crate for evidence of rough handling in shi-
pment. Unpack carefully. If damage to contents is found, report the damage immediately to the
delivering agency.
2.1 Parts Included
a) Gas fired, direct vent, cast iron water boiler
with electronic ignition
b) Factory wired high water temperature limit
switch - auto reset type
c) Factory installed brass ball valve boiler
drain. Ball valve rotates 3600. Depending on
the initial position of the ball valve, each 1/4
turn will open or close the valve
d) Factory installed temperature - pressure
gauge
e) Four Adjustable leveling feet, installation
required
f) ASME approved relief valve and piping -
installation required
g) Ship with literature package - Installer’s
Guide, Service Facts, Functional Parts List,
and User’s Information Guide
h) Manual gas supply shut off valve - installa-
tion required
i) Z-vent special gas vent adapter, 3” female x
3” female
Figure 1
1. Blank Cover Plate*
2. Pressure-Temperature gauge
3. Unused space for Optional Manual Limit
Reset Switch
4. Service light
5. Supply water thermostat
6. Service switch (on/off)
7. Water temperature limit switch (automa-
tic reset, located behind the control panel
inside the control box)
8. Gas manifold pressure port
9. Pressure gauge connection with check
valve
*For Future Optional Accessory
10. Thermo-well
11. Fan
12. Boiler Drain
13. Pilot light unit
14. Main Burner
15. Gas Valve
16. Ignition Control Module
17. Air pressure switch
18. Vent connector collar
19. Supply - 1” NPT male
20. Gas Connection - 1/2” NPT male
21. Return - 1” NPT male
23.62
19.68
17
16
15
18
10
11
12
123457
6
9
13 14
19
20
21
8

18-CG02D1-4
7
2.2 General Specifications - Table 1
Product Specifications
Model *GRWF130
Ratings
Input BTUH 130,000
DOE Output BTUH 110,000
Net (I=B=R®) Output BTUH 96,000
AFUE 84.3
Natural Gas Supply
Pilot gas orifice Qty X ID 1 x 0.40mm
Main gas orifices Qty X ID 3 x 3.10mm
Supply pressure (in. w.c.) 7.0
Manifold pressure (in. w.c.) 3.6
Flow rate BTUH 130,000
LP Gas Supply
Pilot gas orifice Qty X ID 1 x 0.24mm
Main gas orifices Qty X ID 3 x 1.90mm
Supply pressure (in. w.c.) 11.0
Manifold pressure (in. w.c.) 10.6
Flow rate BTUH 130,000
Heating
Max working temperature °F 230
Maximum working pressure (psig) 60
No. sections 4
No. burners 3
Boiler water content (gal.) 3.06
ASME Pressure Relief Valve (psi) 30
Dimensions, weights connections
Height (inches) 33.46
Width (inches) 19.69
Depth (inches) 24.21
Shipping Weight (lb.) 364
Net Weight (lb.) 320
Gas system connection 1/2” NPT male
Heating water supply 1” NPT male
Heating water return 1” NPT male
Electrical power supply V / Ph / Hz 115 / 60 / 1
Minimum Circuit Ampacity (amps) less than 2.0
Maximum Overcurrent Protection
(amps) 15
* May be “A” or “T”

18-CG02D1-4
8
2.3 Codes & Regulations
The manufacturer assumes no responsibility for
equipment installed in violation of any code or regu-
lation.
Codes and local utility requirements governing the
installation of gas fired equipment, wiring, plum-
bing, and flue connections must be adhered to. In
the absence of local codes, the installation must
conform with the:
a) National Fuel Gas Code ANSI Z223.1 “latest
edition” or CAN/CGA B149 Installation Codes.
The latest code may be obtained from the
American Gas Association Laboratories, 400 N.
Capitol St. NW, Washington D.C. 20001
1-800-699-9277 or www.aga.org
b) Standard for Controls and Safety Devices for
Automatically Fired Boilers, ANSI/ASME CSD-1
where required.
c) National Electrical Code NFPA -70.
This boiler is classified Category III according to
ANSI Z21.13 and under the “latest edition” provi-
sions of NFPA54/ANSI Z223.1 and CAN/CGA 149
installation codes. Category III boilers operate
with a positive vent static pressure and with a vent
gas temperature that avoids excessive condensate
in the vent. Installation of the vent system must
be in accordance with the National Fuel Gas Code,
NFPA54/ANSI223.1 or applicable provisions of local
building or fire codes.
It is recommended that Manual J of the Air Con-
ditioning Contractors Association (ACCA) or A.R.I.
230 be followed in estimating heating requirements.
When estimating heating requirements for installa-
tion at Altitudes above 2000 ft., remember the gas
input must be reduced (See GAS INPUT ADJUST-
MENT).
2.4 Locations & Clearances
▲
▲
WARNING
!
FIRE HAZARD
DO NOT INSTALL THIS BOILER DIRECTLY ON
CARPETING.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
NOTE: THIS PRODUCT IS APPROVED FOR IN-
STALLATION ON NON-COMBUSTIBLE FLOOR-
ING MATERIALS EXCEPT FOR CARPET.
▲
▲
WARNING
!
FIRE HAZARD
DO NOT INSTALL THIS BOILER WHERE FLAM-
MABLE LIQUIDS ARE STORED OR WHERE
FLAMMABLE VAPORS ARE PRESENT.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲WARNING
!
SAFETY HAZARD
THESE BOILERS ARE NOT APPROVED OR
INTENDED FOR INSTALLATION IN MANUFAC-
TURED (MOBILE) HOUSING, TRAILERS, OR
RECREATIONAL VEHICLES.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
WARNING
!
WATER HAZARD
DO NOT USE THIS UNIT IF ANY PART HAS
BEEN UNDER WATER. IMMEDIATELY CALL
A QUALIFIED SERVICE TECHNICIAN TO IN-
SPECT THE BOILER AND TO REPLACE ANY
PART OF THE CONTROL SYSTEM AND ANY GAS
CONTROL WHICH HAS BEEN UNDER WATER.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
a) Location Considerations
The location of the boiler is normally selected by
the architect, the builder, or the installer. Howe-
ver, before the boiler is moved into place, be sure
to consider the following requirements:
1. Is the location selected near the chimney or
vent?
2. Do all clearances between the boiler and the
enclosure equal or exceed the minimum stated in
the clearance table?
3. Is there sufficient space for servicing the boiler
and other equipment? A minimum of 36” front
and top accessibility to the boiler must be pro-
vided. Any access door or panel must permit
removal of the largest component.
4. Are the ventilation and combustion air ope-
nings large enough and will they remain unob-
structed? If outside air is used, are the openings
set above the highest snow accumulation level?
(See page 18 for Combustion and Ventilation
section)
5. The boiler is approved for installation directly
on combustible and non-combustible flooring. Do
not install on carpet.
6. Ensure the boiler structure will support the
weight of the boiler.
7. Locate the boiler so that all system components
are protected from water damage during opera-
tion or service.
8. In some applications, boilers may need to be
raised above the floor level to reduce the risk of
water damage.
9. In garage applications, refer to ANSI Z223.1 for
guidance.
10. All boilers installed above the level of heat
emitters must have a low water cut-off device
installed. Refer to National, State or Local codes
for guidance.
11. Slowly scaling if only 1/8” in here.

18-CG02D1-4
9
b) Minimum Clearances
Table 2
Minimum Clearances
for Combustion
Recommended Clearances
for Service
Top 6” 36”
Right Side 6” 24”
Left Side 6” 6”
Front 18” 30”
Back 6” 6”
2.5 Outline Drawings
Dimensions and Connections - Figure 2
Side viewRear view Front view
4.72
1.57
6.18
19.45
1.97
6.42
7.17 15.75
27.87
23.62
33.46
A1
19.68
A3
A2
All dimensions are in inches
*GRWF130 1"
A2
1/2"
A3
Type and model
1"
A1
* May be "A" or "T"
NOTE: All threads are NPT, male connections
Heating
Return Heating
Supply Gas
Inlet
Table 3

18-CG02D1-4
10
3.0 Installation Instructions
3.1 Uncrating Boiler
▲
▲
WARNING
!
SAFETY HAZARD
WHEN MOVING THE BOILER TO THE INSTAL-
LATION LOCATION, ENSURE THE STRUC-
TURE (I.E. FLOORS, STAIRS, PEDESTALS)
CAN SUPPORT THE WEIGHT OF THE BOILER,
DOLLY AND OTHER MOVING EQUIPMENT
AND THE PERSONNEL MOVING THE BOILER.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
. ▲
▲
WARNING
!
SAFETY HAZARD
BEFORE SETTING THE BOILER AT THE
INSTALLATION LOCATION ENSURE THE
FLOOR STRUCTURE WILL SUPPORT THE
WEIGHT OF THE BOILER.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
WARNING
!
HEAVY OBJECT HAZARD
A BOILER IS A HEAVY OBJECT. DO NOT
HANDLE OR WORK UNDER A BOILER
WITHOUT PROPERLY SECURING IT THROUGH
SHORING, BLOCKING OR CRIBBING. FOLLOW
ALL STATE AND FEDERAL CODES AND OSHA
REGULATIONS AND GUIDELINES FOR HAN-
DLING THE BOILER DURING INSTALLATION
AND SERVICING.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
▲
▲
CAUTION
!
Use caution when inserting and removing safety
blocks. Make sure boiler will not fall off safety
blocks.
Failure to obey caution could result in personal
injury.
Figure 4
When boiler
is ready to
be uncrated,
use a saw to
cut the four
vertical corner
boards just
above the base
of the crate. Figure 3
1. Move crated boiler as close as possible to the loca-
tion to be installed. Uncrate the boiler using
a saw to cut the four bottom corner posts even
with the top of the pallet. The top of the crate
can then be lifted off of the boiler. See Figures
3 and 4.
2. If the boiler cannot be moved with crate assem-
bled, uncrate the boiler and use an appliance
dolly of structure worthy to carry the boiler
to move the boiler to the selected location. If
required, the boiler jacket may be removed to
simplify handling (see section 3.2, 5 a through
f). Use a saw to cut the four corner posts even
with the top of the pallet. The top of the crate
can then be lifted off of the boiler.
3. Remove boiler front access panel (Figure 17).
Locate and remove the four bolts securing the
boiler base to the pallet.

18-CG02D1-4
11
3.2 Setting Boiler
1. Verify the floor structure where the boiler will
be set can support the weight of the boiler.
2. Locate the boiler so all components are pro-
tected from water damage during operation.
3. As required, raise the boiler above the floor
level to reduce the risk of water damage.
4. Consult ANSI Z223.1 for garage applications.
5. Move the boiler to the installation location with
an appliance dolly. If required, the boiler jacket
may be removed to simplify handling.
To remove the boiler jacket, follow the steps listed
below.
a. Remove the front access panel (see Figure 17).
b. Remove the top access panel (see Figure 18).
c. Raise the cover on the control panel (See Figure
18) and locate the screw access holes at the top
left and right of the panel. Insert a phillips
screwdriver and remove the two screws. Lower
the control box.
d. Remove the left and right boiler jacket panels
by removing the phillips screws securing the
panels. See Figure 20.
e. Move and set the boiler.
f. Reassemble the boiler jacket, control panel
and front access panel. Leave the top panel off
until the boiler is leveled using the adjustable
feet.
3.3 Leveling the Boiler
1. Locate the leveling feet (4) shipped in a bag with
the boiler.
2. Tilt the boiler toward the front and place a safety
block under the rear of the boiler beyond the front
side of the rear flat adjustable feet location. The back
of the boiler must be elevated high enough to facili-
tate installation and adjustment of the leveling feet.
See Figure 5. Install the adjustable feet. Remove the
safety block.
3. Tilt the boiler toward the rear and place a safety
block under the front of the boiler just beyond the
back side of the boiler front adjustable feet location.
The front of the boiler must be elevated high enough
to facilitaqte installation and adjustment of the
leveling feet. See Figure 6. Install and adjust front
leveling feet. Remove the safety block.
4. Remove the top panel from the boiler. Place a
torpedo level on top of the metal control box. Adjust
leveling feet to make sure boiler is level using steps
2-3.
Figure 5
Install
Rear Leveling
Feet
Figure 6
Install
Front Leveling
Feet

18-CG02D1-4
12
3.4 Water Connections and Piping
Systems
▲
▲
WARNING
!
CONTAMINATION HAZARD.
AIR IN BOILER PIPING SYSTEM LEADS TO
OXYGEN CONTAMINATING THE SYSTEM.
OXYGEN CONTAMINATION LEADS TO CORRO-
SION AND PREMATURE BOILER FAILURE. THE
BOILER STANDARD LIMITED WARRANTY DOES
NOT COVER OXYGEN CONTAMINATION OF
BOILER OR SCALE DEPOSITS CAUSED BY MAKE
UP WATER ADDED TO THE SYSTEM.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.
NOTE: DO NOT use the water system pipes to
ground electrical appliances.
For good operation and long life of the boiler, the
piping system must be well proportioned.
If the supply and return pipes follow a path where air
pockets could form in certain places, it is advisable
to install air vents at these points. Also, install a
discharge device at the lowest point in the system to
allow complete draining of the system.
If the boiler is installed at a lower level than the
system, it is advisable to install a weighted flow
check valve in the supply line to prevent the natural
circulation of system water when the system is off.
The return water temperature to the boiler must
be above 110° F. The temperature drop between the
delivery manifold should not exceed 68° F.
Before installation, carefully flush the system with
water to remove residues or impurities that could
affect the boiler's operation and service life.
Piping
1. The supply and return water connections are loca-
ted on the back of the boiler.
2. The installation of piping shall be in accordance
with National, State and local codes.
3. Supply and Return connections are 1” NPT male.
When connecting supply and return water lines, use
a good quality pipe joint compound. For locations,
see Figure 7.
4. Gas connection is a 1/2” NPT male. See Figure 7.
5. Boiler drain ships factory installed. See Figure 8.
6. Use good quality joint compound that is resistant
to the chemical reaction with liquified petroleum
gasses.
7. It is advisable to install isolation valves between
the boiler and heating system and on the inlet and
outlet side of all hydronic system components for
service. This allows the boiler or components to be
isolated from the system if necessary.
8. Ensure the hydronic system is properly supported
so that no stress is applied to the boiler connections.
Figure 7
Fresh Air
Connection
Return
Water
Hot Water
Supply
Vent
Connection
Boiler Drain
Pilot &
Ignitor
Control
Panel
Ignition
module &
Gas Valve
Gas Manifold
Figure 8
Gas Supply
Connection

18-CG02D1-4
13
Characteristics of system water
In the presence of water harder than 14 grains per gallon,
we recommend the use of suitably conditioned water
in order to avoid possible scaling in the boiler, caused
by hard water, or corrosion produced by aggressive
water. It should be remembered that, because of its
low thermal conductivity, even scaling of just a few
mm thick causes significant overheating of the boiler
walls leading to premature boiler failure.
Water treatment is indispensable in the case of very
large systems (containing large amounts of water) or
with frequent introduction of replenishing water in
the system. If partial or total emptying of the system
becomes necessary under these conditions, it is advisable
to refill it with treated water.
Proper boiler operating pressures
The system pressure when cold should be about 12psi.
For correct operation of the boiler, when hot, its pressure
should be between 18-24 psi.
Figure 9 - Head Loss versus Flow Chart for Models *GRWF130
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 5 10 15 20 25
Water Flow (GPM)
Head Loss (Ft.)
▲
▲
WARNING
!
SAFETY HAZARD.
PRESSURE RELIEF VALVE OUTLET MUST BE
ROUTED TO WITHIN 6” OF A FLOOR DRAIN OR
OTHER AREA SAFE FOR DISCHARGE OF HOT
WATER AND SAFE FROM FREEZING. THIS
PIPE MUST BE FULLY 3/4” IN SIZE THE ENTIRE
LENGTH AND IT MUST NOT CONTAIN ANY
RESTRICTIONS, TRAPS, VALVES, PLUGS, OR
CAPS.
FAILURE TO FOLLOW THIS WARNING COULD
RESULT IN SERIOUS INJURY, DEATH, OR PRO-
PERTY DAMAGE.

18-CG02D1-4
14
I. Typical System Piping Diagrams
Back Flow
Preventer
Globe
Valve
Globe
Valve
Globe
Valve
Pressure
Reducer
Pressure
Gauge
Air
Separator
Circulator
Pump
Flow
Check
Boiler
Heat Emitter
Heat Emitter
Baseboard
Convection
Fin Tube
Expansion Tank
Fresh Air Inlet
Return
Return water temperature must be above 110OF
Supply
Typical System Piping Diagram
Single Zone System - High Temperature with Low Mass Heat Emitters
Relief
Valve
1
1
NOTES: Locate the circulator inlet close to the connection point of the expansion tank, but allow at least the equivalent of 10 to 12 pipe diameters between the circulator pump inlet and the expansion tank to reduce the possibility of pump noise and facilitate air removal.
Exhaust Vent

18-CG02D1-4
15
Circulator
Pump
Circulator
Pump 3-Way
Motorized Valve
Boiler
Back Flow
Preventer
Globe
Valve
Globe
Valve
Globe
Valve
Pressure
Reducer
Pressure
Gauge
Air
Separator
Expansion Tank
Typical System Piping Diagram
Primary Secondary Loop with 3-way Motorized Valve Low Temperature with Low Mass Heat Emitters or High Temperature with High or Low Mass Heat Emitters
Return Water
Temperature
Sensor
Supply Water
Temperature
Sensor
Heat Emitter
Return water temperature must be above 110OF
NOTES: Protects boiler from too low return water temperature and condensation. Locate the circulator inlet close to the connection point of the expansion tank, but allow at least the equivalent of 10 to 12 pipe diameters between the circulator pump inlet and the expansion tank to reduce the possibility of pump noise and facilitate air removal. Close coupled Tees
Relief
Valve
1
2
1
2
3
3
Fresh Air Inlet
Return
Supply
Exhaust Vent

18-CG02D1-4
16
Circulator
Pump
4-Way Motorized Valve
Boiler
Back Flow
Preventer
Globe
Valve
Globe
Valve
Globe
Valve
Pressure
Reducer
Pressure
Gauge
Air
Separator
Expansion Tank
Typical System Piping Diagram
Primary Secondary Loop with 4-way Motorized Valve with Circulator in Secondary Loop Only Low Temperarure with Low Mass Heat Emitters or High Temperature with High or Low Mass Heat Emitters
Return Water
Temperature
Sensor
Supply Water
Temperature
Sensor
Return water temperature
must be above 110OF
Relief
Valve
Heat Emitter
1
2
1
2
NOTES: Protects boiler from too low return water temperature and condensation. Locate the circulator inlet close to the connection point of the expansion tank, but allow at least the equivalent of 10 to 12 pipe diameters between the circulator pump inlet and the expansion tank to reduce the possibility of pump noise and facilitate air removal.
Fresh Air Inlet
Return
Supply
Exhaust Vent

18-CG02D1-4
17
4-Way Motorized Valve
Boiler
Back Flow
Preventer
Globe
Valve
Globe
Valve
Globe
Valve
Pressure
Reducer
Pressure
Gauge
Air
Separator
Expansion Tank
Typical System Piping Diagram
Primary Secondary Loop with 4-way Motorized Valve with Circulators in Primary and Secondary Loops Low Temperarure with Low Mass Heat Emitters or High Temperature with High or Low Mass Heat Emitters
Circulator
Pump
Circulator
Pump
Return Water
Temperature
Sensor
Supply Water
Temperature
Sensor
Return water temperature
mustbeabove110
OF
Heat Emitter
2
1
2
1
3
3
NOTES: Protects boiler from too low return water temperature and condensation. Locate the circulator inlet close to the connection point of the expansion tank, but allow at least the equivalent of 10 to 12 pipe diameters between the circulator pump inlet and the expansion tank to reduce the possibility of pump noise and facilitate air removal. Close coupled Tees
Fresh Air Inlet
Return
Supply Relief
Valve
Exhaust Vent

18-CG02D1-4
18
3.5 Combustion Air and Ventilation
Important: All aspects of the installation of this boiler,
including materials, methods of providing combustion
air and methods of venting products of combustion to the
outdoors must comply with all local codes and the fol-
lowing national standards:
1) CSA B149.1 (most recent edition) - Natural Gas and
Propane Installation Code (Canada)
2) NFPA 54 (most recent edition) - National Fuel Gas Code
(US)
3) NFPA 58 (most recent edition) - Liquefied Petroleum
Gas Code (US)
Adequate flow of combustion and ventilating air must not
be obstructed from reaching the boiler. Air openings pro-
vided in the boiler casing must be kept free of obstructions
which restrict the flow of air. Airflow restrictions affect
the efficiency and safe operation of the boiler. Keep this
in mind should you choose to remodel or change the area
which contains your boiler. Boilers must have a free flow
of air for proper performance.
Provisions for combustion and ventilation air shall be
made in accordance with “latest edition” of Section 5.3, Air
for Combustion and Ventilation, of the National Fuel Gas
Code, ANSI Z223.1, or Sections 7.2, 7.3 or 7.4 of CAN/CGA
B149 Installation Codes, and applicable provisions of the
local building codes. Special conditions created by me-
chanical exhausting of air and fireplaces must be consid-
ered to avoid unsatisfactory boiler operation.
Boiler locations may be in “confined space” or “unconfined
space”. Unconfined space is defined in Table 4 and Figure
10.
50 CU. FT. OR MORE
PER 1000 BTU/HR. INPUT
ALL EQUIP. INSTALLED
UNCONFINED
Fig. 10
CONFINED
LESS THAN 50 CU. FT.
PER 1000 BTU/HR. INPUT
ALL EQUIP INSTALLED
Fig. 11
These spaces must have adequate air by infiltration to
provide air for combustion, ventilation, and dilution of
flue gases. Buildings with tight construction (for example,
weather stripping, heavily insulated, caulked, vapor bar-
rier, etc.), may need additional air provided as described for
confined space.
Confined spaces are installations with less than 50 cu. ft. of
space per 1000 BTU/hr input from all equipment installed.
Air for combustion and ventilation requirements can be
supplied from inside the building as in Figure 12 or from
the outdoors, as in Figure 13.
1. All air from inside the building as in Figure 12: The
confined space shall be provided with two permanent
openings communicating directly with an additional
room(s) of sufficient volume so that the combined vol-
ume of all spaces meets the criteria for an unconfined
space. The total input of all gas utilization equipment
installed in the combined space shall be considered
in making this determination. Refer to Table 4, for
minimum open areas required.
2. All air from outdoors as in Figure 13: The confined
space shall be provided with two permanent open-
ings, one commencing within 12 inches of the top and
one commencing within 12 inches of the bottom of the
enclosure. The openings shall communicate directly,
or by ducts, with the outdoors or spaces (crawl or attic)
that freely communicate with the outdoors. Refer to
Table 5, for minimum open areas required.
A variety of potential sources of carbon monoxide can be
found in a building or dwelling such as gas-fired clothes
dryers, gas cooking stoves, water heaters, boilers and
fireplaces. The U.S. Consumer Product Safety Commission
recommends that users of gas-burning appliances install
carbon monoxide detectors as well as fire and smoke
detectors per the manufacturer’s installation instructions
to help alert dwelling occupants of the presence of fire,
smoke or unsafe levels of carbon monoxide. These devices
should be listed by Underwriters Laboratories, Inc. Stan-
dards for Single and Multiple Station Carbon Monoxide
Alarms, UL 2034 or CSA International Standard, Residen-
tial Carbon Monoxide Alarming Devices, CSA 6.19.
TABLE 4
Minimum Area in Square Feet for Unconfined
Space Installations
Boiler Maximum
BTUH / Input Rating With 8 Foot Ceiling Minimum Area in Square
Feet of Unconfined
Space
90,000 560
130,000 810
173,000 1080
215,000 1340
TABLE 5
Minimum Free Area in Square Inches Each
Opening (Boiler Only)
Boiler
Maximum
BTUH /
Input Rating
Air From
Inside Air From Outside
Vertical
Duct Horizon- tal Duct
90,000 100 25 50
130,000 130 35 70
173,000 175 45 90
215,000 215 55 110

18-CG02D1-4
19
3. The following types of installations will require use of
OUTDOOR AIR for combustion, due to chemical expo-
sures:
* Commercial buildings
* Buildings with indoor pools
* Boilers installed in commercial laundry rooms
* Boilers installed in hobby or craft rooms
* Boilers installed near chemical storage areas.
Exposure to the following substances in the combustion
air supply will also require OUTDOOR AIR for combus-
tion:
* Permanent wave solutions
* Chlorinated waxes and cleaners
* Chlorine based swimming pool chemicals
* Water softening chemicals
* Deicing salts or chemicals
* Carbon Tetrachloride
* Halogen type refrigerants
* Cleaning solvents (such as perchloroethylene)
* Printing inks, paint removers, varnish, etc.
* Hydrochloric acid
* Cements and glues
* Antistatic fabric softeners for clothes dryers
* Masonry acid washing materials
Figure 12
Figure 13
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation could result in carbon monoxide
poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation:
1. Seal any unused openings in the venting system.
2. Inspect the venting system for proper size and
horizontal pitch, as required in the National Fuel Gas
Code, ANSI Z223.1/NFPA 54 or the CAN/CGA B149
Installation Codes and these instructions. Determine
that there is no blockage or restriction, leakage,
corrosion and other deficiencies which could cause an
unsafe condition.
3. As far as practical, close all building doors and
windows and all doors between the space in which the
appliance(s) connected to the venting system are
located and other spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not
connected to the venting system. Turn on any exhaust
fans, such as range hoods and bathroom exhausts, so
they are operating at maximum speed. Do not operate
a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance
being inspected into operation. Adjust the thermostat
so appliance is operating continuously.
7. If improper venting is observed during any of the above
tests, the venting system must be corrected in
accordance with the National Fuel Gas Code,
ANSI Z221.1/NFPA 54 and/or CAN/CGA B149
Installation Codes.
8. After it has been determined that each appliance
connected to the venting system properly vents where
tested as outlined above, return doors, windows,
exhaust fans, fireplace dampers and any other gas-fired
burning appliance to their previous conditions of use.
▲WARNING
!

18-CG02D1-4
20
3.6 GENERAL VENTING INSTRUCTIONS
VENT PIPING
▲
WARNING
!
FIRE AND CARBON MONOXIDE HAZARD
USE ONLY AN APPROVED AL29-4C® STAINLESS
STEEL VENT SYSTEM, PROPERLY INSTALLED, TO
VENT FLUE GASES FROM THIS BOILER. FAILURE
TO FOLLOW THIS WARNING COULD RESULT IN SE-
RIOUS INJURY, DEATH, OR PROPERTY DAMAGE.
▲
WARNING
!
FIRE HAZARD AND CARBON MONOXIDE HAZARD
DO NOT USE A VENT DAMPER WITH THIS BOILER.
FAILURE TO FOLLOW THIS WARNING COULD RE-
SULT IN SERIOUS INJURY, DEATH, OR PROPERTY
DAMAGE.
▲
WARNING
!
CARBON MONOXIDE HAZARD
THE EXHAUST VENT SYSTEM MUST BE MADE UP
ENTIRELY OF COMPONENTS FROM THE SAME
MANUFACTURER AND STYLE. DO NOT MIX BRANDS
OR STYLES OF PIPES AND FITTINGS. THE VENT
SYSTEM COULD FAIL TO SEAL, RESULTING IN FLUE
GAS SPILLAGE INTO THE LIVING AREA. FAILURE TO
FOLLOW THIS SAFETY WARNING COULD RESULT IN
SERIOUS INJURY, DEATH, OR PROPERTY DAMAGE
This boiler is classified Category III according to ANSI
Z21.13 and under the “latest edition” provisions of NFPA54/
ANSI Z223.1 and CAN/CGA 149 installation codes. Cat-
egory III boilers operate with a positive vent static pres-
sure and with a vent gas temperature that avoids excessive
condensate in the vent. Installation of the vent system
must be in accordance with the National Fuel Gas Code,
NFPA54/ANSI223.1 or applicable provisions of local build-
ing or fire codes.
For venting the flue gases, this boiler requires a special
gas vent system consisting of single wall pipe and fittings,
constructed of AL-29-4C® stainless steel. The system
must be gasketed and must be water-tight and air-tight.
The special gas vent system must be listed by Underwriters
Laboratories Inc. as having been tested and conforming to
Standards UL 1738 AND ULCS636 such as Z-Vent, Model
SVE, Series III or equivelant. This vent system must be
provided by the installer. Installation must strictly con-
form with the vent system manufacturer’s instructions.
Example instructions from Z-Flex® are included for refe-
rence in the appendix at the end of this document.
This boiler includes one 3.00” OD exhaust vent collar suit-
able for attaching a universal adapter compatible with the
special vent system provided by the installer. One 3” Z-
Vent Adapter #2SVSNA03.5 (female, both ends) is shipped
with the boiler. If a different UL listed vent system sup-
plier is selected, the installer must furnish the appropriate
appliance adapter.
Do not mix exhaust venting components made by one
manufacturer with those made by another.
Vent
System Material Equivalent Length
3" 90° Elbow, Z-Vent Model SVE,
Series III or Equal 3 Equivalent Feet, Each
3" Rain Cap, Z-Vent Model SVE,
Series III or Equal 3 Equivalent Feet, Each
3" Straight Pipe, Z-Vent Model
SVE, Series III or Equal 1 Equivalent Foot, for Each Foot of Straight Pipe
3" 90° Elbow, Sch 40 PVC 8 Equivalent Feet, Each
3" Straight Pipe, Sch 40 PVC 1 Equivalent Foot, for Each
Foot of Straight Pipe
3" 90° Elbow, B-Vent 3 Equivalent Feet, Each
1 Foot Length Of 3" Straight Pipe,
B-Vent 1 Equivalent Foot, for Each Foot of Straight Pipe
Table 6A Category III Boiler - Approved Venting Systems
Flue
Exhaust
Fresh Air
Intake
Fresh Air
Intake -
Alternate
Where sealant is required, use GEIS806 High Temperature
Sealant (500°F, 260°C).
This boiler is suitable for either direct vent installation or
for installation using indoor combustion air.
For direct vent installations, this boiler may be connected
to either a vertical or horizontal two pipe system. The
exhaust vent and fresh air intake must not exceed the ma-
ximum permissable equivalent feet in length. See table 6A
and 6B for vent lengths.
Removal of Restrictor Orifice for Flue Gas Vent Pipe
Lengths of 35 Feet or More
NOTE:
Remove the restrictor orifice in the combustion fan motor
outlet fitting when the total sum of the equivalent length
of the flue gas pipe system and the equivalent length of the
fresh air pipe system equals or exceeds 35 feet!
Boiler is shipped with a flue gas vent pipe restrictor orifice
in place. This orifice must be removed if the total sum of
the equivalent length of the flue gas pipe system and the
equivalent length of the fresh air pipe system equals or
exceeds 35 feet!
To remove the vent pipe restrictor orifice:
1. Remove the flue gas vent pipe adapter from the
discharge fitting of the combustion fan motor (CFM) (see
Figure 13A).
2. Remove the flexible gasket from the discharge fitting of
the CFM (see Figure 13B).
3. Remove the flue gas vent pipe restrictor orifice (see
Figure 13C.)
4. Replace the flexible gasket in the discharge fitting of the
CFM (see Figure 13B).
5. Replace the flue gas vent pipe adapter (see Figure 13A).
FRESH AIR (COMBUSTION AIR) PIPING
PVC pipe may be used for fresh (combustion) air. This
boiler includes one pre-installed 3.5” OD combustion air
vent collar suitable for attaching a schedule 40 PVC fitting
or coupling. Use silicone sealant to seal and hold the fitting
With restrictor in place
(as shipped)
The sum of the flue exhaust pipe equivalent length
and the fresh air intake pipe equivalent length must
be at least 35 feet and not more than 135 feet
* Approved pipe length depends on the presence of a flue gas restrictor
orifice in the outlet of the combustion fan motor (CFM).
Table 6B Category III Boiler - Approved Vent Pipe Lengths*
With restrictor removed
(see instructions below)
The sum of the flue exhaust pipe equivalent length
and the fresh air intake pipe equivalent length
must be less than 35 feet