Williams 2001622A,3501522A,3501922A,5001522A,5001922A,6501522A,6501922A,2001621A,3501521A,3501921A,5001521A,5001921A,6501521A,6501921A,3502522A,3502922A,5002522A,5002922A,6502522A,6502922A,3502521A,3502921A,5002521A,5002921A,6502521A,6502921A Owners Manual

TM

OWNER’S MANUAL

INSTALLATION INSTRUCTIONS

VISITEZ NOTRE SITE WEB POUR LA VERSION FRANÇAISE DE CE MANUEL
VISITE NUESTRA PÁGINA WEB PARA LA VERSIÓN EN ESPAÑOL DE ESTE MANUAL

https://www.williamscomfortprod.com/products/furnaces/

VENTED ROOM HEATERS

ENCLOSED FRONT MODEL NUMBERS (natural gas)
2001622A / 3501522A / 3501922A / 5001522A
5001922A / 6501522A / 6501922A

ENCLOSED FRONT MODEL NUMBERS (propane gas)
2001621A / 3501521A / 3501921A / 5001521A
5001921A / 6501521A / 6501921A

FIREPLACE FRONT MODEL NUMBERS (natural gas)
3502522A / 3502922A / 5002522A
5002922A / 6502522A / 6502922A

FIREPLACE FRONT MODEL NUMBERS (propane gas)
3502521A / 3502921A / 5002521A
5002921A / 6502521A / 6502921A

SAVE THIS MANUAL FOR FUTURE REFERENCE.

READ THIS OWNER’S MANUAL CAREFULLY BEFORE YOU
INSTALL YOUR NEW WILLIAMS WALL FURNACE.

ENCLOSED

MODEL

FIREPLACE

MODEL

WARNING: If the information in these instructions
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
WARNING: Do not install any of these furnaces
(natural or propane gas) in mobile/manufactured homes,
trucks or recreational vehicles.

WARNING: This product can expose you to
chemicals including epichlorohydrin which is known to
the State of California to cause cancer and birth defects
and/or other reproductive harm. For information go to
www.p65warnings.ca.gov

WARNING: Improper installation, adjustment,
alteration, service or maintenance can cause injury or
property damage. Refer to this manual. For assistance or
for additional information consult a qualified installer or,
service agency.

and liquids in the vicinity of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS:

•

Open all windows.

•

Do not try to light any appliance.

•

Do not touch any electrical switch; do not use

any phone or cell phone in your building.

•

Extinguish any open flame.

•

Immediately call your gas supplier from a neighbor’s

phone. Follow the gas supplier’s instructions.

•

If you cannot reach the gas supplier, call the fire

department.
– Installation and service must be performed by a

qualified installer, service agency or the gas supplier.

250 West Laurel Street, Colton CA 92324 • WWW.WFC-FC.COM • 1-888-444-1212

WARRANTY

The manufacturer, Williams Furnace Co., warrants this wall furnace
or heater to the original purchaser under the following conditions:

ANY WARRANTY CONSIDERATIONS ARE
CONTINGENT ON INSTALLATION BY A
QUALIFIED INSTALLER (CONTRACTOR).
SELF-INSTALLATION IS PROHIBITED AND
WILL INVALIDATE YOUR WARRANTY.

LIMITED ONE-YEAR WARRANTY

1. Any part thereof which proves to be defective in material or
workmanship within one year from date of original purchase
use will be replaced at the Manufacturer’s option, FOB to its factory.

2. No liability is assumed by the Manufacturer for removal or

installation labor costs, nor for freight or delivery charges.

LIMITED EXTENDED WARRANTY

1. In addition to the above limited one year warranty on the

complete unit, any combustion chamber which burns out or
rusts under normal installation, use and service conditions
during a period of nine years following expiration of the
one-year warranty period will be exchanged for a like or
functionally similar part.

2. No liability is assumed by the Manufacturer for removal or

installation labor costs, nor for freight or delivery charges.

LIMITATIONS

1. THIS LIMITED WARRANTY IS THE ONLY WARRANTY MADE BY

THE MANUFACTURER, IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR
PURPOSE ARE LIMITED TO THE SAME ONE YEAR TERM AS
THE EXPRESS WARRANTY. UNDER NO CIRCUMSTANCES
SHALL THE MANUFACTURER BE LIABLE FOR INCIDENTAL,
CONSEQUENTIAL, SPECIAL OR CONTINGENT DAMAGES OR
EXPENSES ARISING DIRECTLY OR INDIRECTLY FROM ANY
DEFECT IN THE PRODUCT OR ANY COMPONENT OR
FROM THE USE THEREOF. THE REMEDIES SET FORTH HEREIN
ARE THE EXCLUSIVE REMEDIES AVAILABLE TO THE USER AND
ARE IN LIEU OF ALL OTHER REMEDIES.

for

Some states do not allow limitation on how long an implied
warranty lasts, and some states do not allow the exclusion or
limitation of incidental or consequential damages, so the above
limitations or exclusions may not apply to you.

This warranty does not include any charge for labor or installation.

2.

3. This warranty does not extend to painted surfaces or to damage
or defects resulting from accident, alteration, misuses or abuse
or improper installation.

4. This warranty does not cover claims which do not involve
defective workmanship or materials.

DUTIES OF THE CONSUMER

1. The heating equipment must be installed by a qualified installer
and operated in accordance with the installation and
homeowner’s instructions furnished with the equipment.

2. Any travel, diagnostic costs, service labor, and labor to repair
the defective unit will be the responsibility of the owner.

3. A bill of sale, canceled check, payment record or permit should
be kept to verify purchase date to establish the warranty period.

4. Have the installer enter the requested information in the
space below.

GENERAL

1. The manufacturer neither assumes nor authorizes any person
to assume for it any other obligation or liability in connection
with said equipment.

2. Service under this warranty should be obtained by contacting
your dealer. Provide the dealer with the model number, serial
number, and purchase date verification.

3. If, within a reasonable time after contacting your dealer,
satisfactory service has not been received, contact: Customer
Service Department, 250 West Laurel Street, Colton, CA 92324
for assistance.

4. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS AND
YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM
STATE TO STATE.

INSTALLATION RECORD

Model No. . Serial No.

Original Purchaser

Address

City and State Zip

Dealer

Address

City and State Zip

HVAC Installation Date HVAC Installer Name

HVAC Signature

(Dealer or authorized representative who certifies that this appliance is installed in accordance with Manufacturer’s instructions and local codes.)

2 VENTED ROOM HEATERS

CONTENTS

YOUR WILLIAMS WARRANTY

INSTALLATION RECORD

TABLE OF CONTENTS

SAFETY RULES

INTRODUCTION

INSTALLING YOUR FURNACE

BASIC MATERIALS NEEDED

HELPFUL INSTALLATION INFORMATION

OPTIONAL ACCESSORIES

UNPACKING YOU HEATER

INSTALLING YOUR HEATER

LOCATING THE HEATER

COMBUSTION & VENTILATION AIR

Quick reference,

2

here’s how to:

2

INSTALLING YOUR FURNACE

3

Furnace locations

4

OPERATING YOUR FURNACE
Igniting your furnace for the first time.

5

6

CARING FOR YOUR HEATER

Learn how to keep your new

6

Williams Furnace operating.

6

6

6

6

6

9

10

16

19

THERMOSTAT INSTALLATION

TYPICAL METHODS OF SAFELY VENTING THE HEATER

STARTUP PROCEDURE

FOR YOUR SAFETY

CARING FOR YOUR HEATER

CLEANING BURNER COMPARTMENT

INSTALLATIONS IN THE STATE OF MASSACHUSETTS

HINTS AND INFORMATION

BLOWER ACCESSORY 2102

FURNACE ACCESSORY REPLACEMENT PARTS 200 MODELS

FURNACE ACCESSORY REPLACEMENT PARTS 350500650 MODELS

BLOWER ASSEMBLY 2102

TROUBLESHOOTING YOUR FURNACE

SERVICE RECORD

12

14

16

17

19

20

21

21

22

23

25

28

29

31

VENTED ROOM HEATERS 3

SAFETY RULES

WARNING: Read these rules and the instructions
carefully. Failure to follow these rules and instructions
could cause a malfunction of the furnace. This could
result in death, serious bodily injury and/or property
damage.

INSTALLATION MUST CONFORM TO LOCAL CODES.
IN THE ABSENCE OF LOCAL CODES, INSTALLATION
MUST CONFORM TO THE NATIONAL FUEL GAS CODE,
ANSI Z223.1. THE APPLIANCE, WHEN INSTALLED MUST
BE ELECTRICALLY CONNECTED AND GROUNDED IN
ACCORDANCE WITH LOCAL CODES OR, IN THE ABSENCE
OF LOCAL CODES, WITH THE CURRENT NATIONAL
ELECTRICAL CODE ANSI/NFPA NO. 70.

IN CANADA:

1. Installation must conform to local codes or, in the
absence of local codes, the current CAN/CGA B149
installation code.

2. The appliance, when installed, must be electrically
connected and grounded in accordance with local
codes or, in the absence of local codes, with the
current CSA C22.1 Canadian Electrical code.

3. Field conversions for high altitude are not
permitted in Canada.

4. Reference is made in this manual regarding gas
type as propane gas. Be advised that propane gas
is not available in Canada, refer to propane.

1. Use only manufacturer’s replacement parts. Use of any

other parts could cause injury or death.

2. DO NOT install the furnace in an alcove.

3. DO NOT install this furnace where it could be isolated

by closing doors to the heated space.

4. DO NOT install this furnace in a travel trailer or

recreational vehicle.

5. MAINTAIN all clearances specified in section “Locating

Wall furnace and Thermostat” and “Vent Installation.”

6. BE SURE this furnace is for the type of gas to be used.

Check the rating plate by the gas valve in the lower
cabinet. Do not change it to use other gases without
the proper manufacturer’s Gas Conversion Kit.

7. For natural gas, the minimum inlet gas supply pressure

for the purpose of input adjustment is 5” water column.
The maximum inlet gas supply pressure is 7” water
column.

For propane gas, the minimum inlet gas supply
pressure for the purpose of input adjustment is 11”
water column. The maximum inlet gas supply pressure
is 13” water column.

8. Any safety screen, guard or parts removed for servicing

this appliance must be replaced prior to operating
the appliance to avoid property damage, bodily injury
or death.

9. Install the furnace vent directly to the outdoors, so
that harmful gases will not collect inside the building.
Follow the venting instructions for your type of
installation exactly. Use only the type and size of vent
pipe and fittings specified.

10. BE SURE to provide for adequate combustion and
ventilation air. The flow of this air to the furnace must
not be blocked.

11. NEVER vent flue gases into another room, a fireplace
or any space inside a building. This could cause
property damage, bodily injury or death.

12. Never test for gas teaks with an open flame. Use a soap
solution to check all gas connections. This will avoid the
possibility of fire or explosion.

13. ALLOW the furnace to cool before servicing. Always
shut off electricity and gas to the furnace when
working on it. This will prevent any electrical shocks
or burns.

14. DUE TO HIGH TEMPERATURES, locate the furnace out
of traffic and away from furniture and draperies.

15. ALERT children and adults to the hazards of high
surface temperatures and warn them to keep away to
avoid burns or clothing ignition.

16. CAREFULLY supervise young children when they are in
the same room with the furnace.

17. DO NOT place clothing or other flammable material on
or near furnace.

18. INSTALLATION and REPAIR must be done by a qualified
service person. The appliance should be inspected
before use and at least annually by a professional
service person. More frequent cleaning may be required
due to excessive lint from carpeting, bedding material,
etc. It is important that control compartments, burners
and circulating air passages be kept clean. Failure to
keep burner-control compartment and other parts of
furnace clean can cause dangerous conditions to develop
which can cause injury and even death.

19. BE AWARE of good safety practices by wearing
personal protective equipment such as gloves and
safety glasses to avoid being injured by sharp metal
edges in or around furnace and while cutting or drilling
holes in wood and/or sheet metal.

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

21. DO NOT store or use gasoline or other flammable
liquids or vapors near the furnace.

22. DO NOT store or use gasoline or other flammable
liquids or vapors near the heater.

WARNING: Do not use this furnace if any part has
been under water. Immediately call a certified service
technician to inspect the furnace and to replace any
part of the control system and any gas control which
has been under water.

4 VENTED ROOM HEATERS

INTRODUCTION

Please read our instructions before you install and use
your heater. This will help you obtain the full value from
this heater. If the answer to the problem is found within
this instruction manual, it could help you avoid needless
service costs.

BASIC DESCRIPTION
Always consult your local heating or plumbing inspector,
building department or gas company regarding
regulations, codes or ordinances which apply to the
installation of a vented room heater.

No electrical power is required unless furnace is equipped
with an optional blower accessory.

The efficiency rating of this appliance is a product thermal
efficiency rating determined under continuous operating
conditions and was determined independently of any
installation system.

Warmed air is discharged into the room in which the
heater is located. The heater contains a single multi-slot
gas burner.

Combustion air is drawn in from the room where the
heater is located and is vented out of the heater vertically
through vent piping to a roof vent top. (Vent equipment
is not supplied with the heater).

The combustion chamber is built of heavy-gauge steel.
The heater cabinet is also constructed of heavy-gauge
steel and has a powder-coat paint finish.

The heater controls are located behind an access door
on the side of the heater. All models are equipped with
CSA/AGA listed gas valves and pilots.

The appliance is equipped with a vent safety shutoff
system, designed to protect against improper venting.
Operation of this room heater when not connected to
a properly installed and maintained venting system or
tampering with the vent safety shutoff system can result
in carbon monoxide (CO) poisoning and possible death.

This heater is design certified in accordance with
American National Standard & CSA Standard Z21.86 and
CSA 2.32 as a vented room heater and must be installed
according to these instructions.

WARNING: 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 Natural Gas
and Propane Installation Code, CSA B149.1 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) Test for spillage from draft hood equipped appliances
at the draft hood relief opening after 5 minutes
of main burner operation. Use the flame of a match
or candle.

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

9) After it has been determined that each appliance
connected to the venting system properly vents
when tested as outlined above, return doors, windows,
exhaust fans, fireplace dampers and any other
gas-fired burning appliance to their previous
conditions of use.

VENTED ROOM HEATERS 5

INSTALLING YOUR FURNACE

Basic Tools Needed



Hand drill or properly grounded electric drill



1/8 inch and 3/16 inch drill bit (metal)



6 foot folding ruler or tape measure



Screwdriver (Phillips Head)



Pliers (Wire Cutting)



Hammer



Stud locator or small finishing nails



8 inch adjustable wrench



Keyhole saw or saber saw



2-10 inch or 12 inch pipe wrenches

Gloves and safety glasses

Basic Materials Needed



Pipe joint compound resistant to propane gases.



Electrical wiring supplied as needed for optional blower.



Pipe and fittings to make connections to the heater.

Helpful Installation
Information

THE FOLLOWING BOOKLETS WILL HELP YOU IN
MAKING THE INSTALLATION:

ANSI/NFPA 70-1990 or current edition “National Electrical
Code”. In Canada: CSA C22.1 Canadian Electrical Code.

American National Standard NFPA54/ANSI Z223.1 1988 or
current edition “National Fuel Gas Code”.

Obtained from: American National Standards Institute,
Inc., 1430 Broadway, New York, N Y 10018.

In Canada: CAN/CGA B149.

Optional Accessories

BLOWER
To increase circulation of warmed air within the heated
space, you may use Blower Accessory Kit 2102, on all
models except 2001622A and 2001621A.

THERMOSTAT P322016

FLOOR BOARD MODEL 4163 OR 4167

Available in black to match the heater.

Unpacking Your Heater

Examine all packing material carefully. Look for loose
parts before discarding. Store all parts where they cannot
be lost or damaged before you need them.

NOTE: Check the burner rating plate, located in the
burner compartment, to make sure your heater is
equipped to operate on the type of gas available (either
natural or propane gas). DO NOT convert unit from

natural gas to propane gas or from propane gas to
natural gas without the proper manufacturer’s gas
conversion kit.

Installing Your Heater

The following steps are needed for proper installation and
safe operation of your heater. If you have any doubts as
to any requirements, check with local authorities for local
and state codes affecting the installation.

Obtain professional help where needed.
DO NOT install this heater in a travel trailer, recreational

vehicle, or mobile home.

IMPORTANT

For satisfactory and trouble-free operation, be sure to:

1. Locate the heater properly within the space to
be heated.

2. Provide for adequate combustion air, adequate air
circulation around the cabinet inside the open room
and a proper vent system.

3. Maintain all minimum clearances which apply to
your heater.

Locating the Heater

WARNING: Gas burning appliances require air for
combustion and proper venting. Minimum fresh air
opening of 1 square inch per 1,000 BTU/hr. input rating
must be provided for ventilation.

EXAMPLE: A 30,000 BTU/hr. input unit requires the
equivalent of a 30 inch wide window be open 1 inch for
safe operation.

WARNING: Danger of property damage,
bodily injury or death. Even when a house meets
requirements for unconfined space with adequate air
infiltration, it is recommended that a fresh air intake
be installed to lessen the possible dangers from any
future changes on the home.

VENT COLLAR MODEL 9102, 9104 OR 9106
Available in black to match the heater.

6 VENTED ROOM HEATERS

Consider the following points before attempting to install
the heater:

1. In choosing the location for the heater, the following
factors should be considered:

a. Convenience to the gas supply.

b. Arrangement of the rooms or area to be heated.
c. Probable location of the furniture.
d. General appearance.
e. Safe clearance from anything that could catch fire.
f. Ability to properly vent the heater.

2. Locate the heater centrally in the area which it is to

heat. The ideal location is at the source of cold air,
which is an outside wall. If the heater is on an outside
wall, the cold air will be warmed before it moves
through the room.

3. Place the heater where the air will circulate freely

throughout the area to be heated. If one heater is
intended to heat the entire house, it is advisable to
consider the installation of grilles immediately below
the ceilings to permit circulation of hot air from room
to room. Return air grilles are also desirable.

4. Be certain the heater is placed where the air is free to

circulate around it. Never install the heater in a wall
recess. The minimum clearance required to any wall
or object can be found on the rating plate located
inside the heater control door on the base plate. We
recommend a 24-inch min. clearance from the burner
access door for the ease of lighting and for observation
of pilot and burner flames.

5. The heater must be installed so that the draft hood is

in the same pressure zone as the combustion air.

6. The heater may be placed directly on wood floors.

Heavy pile or shag rugs may restrict normal air flow.
Some floor coverings discolor easily from even low
heat. To assure safe operation, a metal or wood panel,
extending the full depth and width of the appliance
must be placed under the heater. Optional floor boards
are available from Williams.

7. Do not place the heater where curtains, draperies, or

any other material may come into contact with
any part of the heater.

plate. On natural gas, the manifold pressure should be 4
inches water column. The manifold pressure should be 10
inches water column for propane gas.

Orifice changes may be required to suit the gas supplied.
For heaters located at elevations between sea level and

2,000 feet, the measured input must not be greater than
the input shown on the rating plate of the heater. For
elevations above 2,000 feet, the measured input must not
exceed the input of the rating plate reduced by 4 percent
for each 1,000 feet that the heater is above sea level.

MINIMUM REQUIRED CLEARNACES

MODEL “A” SIDE “B” CEILING “C” REAR

200 SERIES 2" 36" 3"

350 SERIES 6" 57" 6"

500 SERIES 6" 57" 6"

650 SERIES 6" 57" 6"

24" MIN. CLEARANCE IS RECOMMENDED ON SIDE WITH

BURNER ACCESS DOOR OR EASE OF LIGHTING AND FOR

OBSERVATION OF PILOT AND BURNER FLAMES.

FIGURE 1 - MINIMUM REQUIRED CLEARNACES

GAS CONTROLS

1. All models are regulated on natural or propane gases.

The regulator is built into the gas control valve.

2. All models are equipped with a 100% pilot safety

shutoff and vent safety shutoff system.

3. CAUTION: Do not connect 115V electrical service line to

gas control valve or wall thermostat.

GAS SUPPLY
For natural gas, the minimum inlet gas supply pressure for
the purpose of input adjustment is 5” water column. The
Maximum inlet gas supply pressure is 7” water column.

For propane. gas, the minimum inlet gas supply pressure
for the purpose of input adjustment is 11” water column.
The maximum inlet gas supply pressure is 13” water
column.

The gas pressure and input to the burners must not
exceed the rated input and pressure shown on the rating

VENTED ROOM HEATERS 7

INSTALLING YOUR FURNACE

NOTE: Minimum fresh air opening is 1 square inch
per 1,000 BTU/hr.

GAS PIPING
State and local authorities have established codes
regulating the installation of gas burning equipment.
Consult your gas supplier or gas company for complete
information. In the absence of local codes, all aspects of
the installation must comply with the National Fuel Gas
Code ANSI Z223.1. In Canada: Follow the CAN/CGA-B149.1(2)
Canadian Standard.

1. Use ½-inch pipe or semi-rigid tubing for natural

and Liquefied Petroleum Gases. DO NOT USE FLEXIBLE
HOSE. Appliance connectors of corrugated metal
tubing and fittings that are listed by a nationally
recognized testing agency may be used if accepted
by the local code authorities. FOLLOW THE
MANUFACTURER’S INSTALLATION INSTRUCTIONS.
This type of connection may only be installed in the
room where the heater is located.

2. A manual shutoff valve and union must be installed

in the gas supply line just ahead of the connection to
the heater. The manual valve must include a 1/8-inch
NPT plugged tapping accessible for connection of a
test gauge.

3. Unions in the gas supply lines should be of the ground

joint type. Compounds used on threaded pipe joints
must be resistant to the action of liquefied petroleum
gases.

FIGURE 2 - LEFT SIDE GAS INLET

WARNING: When connecting field piping,

use a second wrench to keep the heater valve from
turning. Support field piping properly, stress and over
tightening could damage the gas valve and result
in dangerous gas leaks which can cause dangerous
conditions including property damage, bodily injury,
and even death.

4. A drip leg Figure 2 should be installed to constitute a

trap to catch any condensate that may be in the gas.
The drip leg should be readily accessible for cleaning.

5. The heater must be disconnected from the gas supply

system and from the heaters individual shutoff valve
when the system is tested at a pressure in excess of
1/2 PSI.

6. Check all factory and field pipe joints for gas leaks

before and after lighting the heater. Use a soap solution.
Never use a match or open flame. Correct any leak(s),
no matter how small.

7. Piping supply shall be supported to prevent sagging

damage to the controls and hazardous gas leaks. To
prevent freezing where the supply pipe is exposed to
cold air, wrap the pipe or run it underground.

FIGURE 3  PROPER PIPING PRACTICE

2 THREADS EXPOSED

PROPER PIPE

THREADING

SEALANT THIN

ENOUGH TO SHOW

THREADS

DAMAGED

THREADS

INCORRECT
THREADING

OVERTHREADED

SEALANT

PAST TIP

SEALANT

TOO THICK

IMPORTANT: All piping must comply with local codes and
ordinances or with the National Fuel Gas Code (ANSI Z223.1
NFPA No. 54), whichever applies. (In Canada: CAN/CGA B149).

8 VENTED ROOM HEATERS

FIGURE 4 - ENCLOSED MODEL

FRONT VIEW ENCLOSED MODEL SHOWN

FIGURE 5 - GAS PIPE SIZES

NATURAL GAS PIPE CAPACITY  BTUhr.

INCLUDES FITTINGS PIPE SIZE

LENGTH
OF PIPE

FEET

20
40
60

1/2"

92,000
63,000
50,000

PIPE SIZE

3/4" 1"

190,000
130,000
105,000

350,000
245,000

195,000

fuel burning appliances. Any use of appliances that
pull air out of the house (clothes dryers, exhaust fans,
fireplaces, etc.) increases this problem and appliances
could be starving for air.

In addition, these energy measures mean that your home
will retain more water vapor or a higher relative humidity.

High humidity, especially during cold weather, may be
damaging to buildings because condensation forms on
windows and inside walls.

The combination of a tight energy efficient home with
the use of exhaust fans, fireplaces, clothes dryers, and gas
appliances result in more and more air being drawn from
the house until fresh air may be sucked back into the
house down a furnace flue or fireplace chimney. Carbon
monoxide can be the result. Carbon monoxide (CO) is a
colorless, odorless gas produced when fuel is not burned
completely or when the flame does not receive sufficient
oxygen. Automobiles, charcoal, wood fires and improperly
vented or air-starved coal, oil and gas furnaces or other
appliances can produce carbon monoxide.

BE AWARE OF THESE AIRSTARVATION SIGNALS:

1. Headaches, nausea, dizziness.

2. Excessive humidity shown by heavily frosted windows
or a moist “clammy” sensation.

3. Fireplace smoke fills the room or will not draw.

4. Furnace flue backs up.

PROPANE GAS PIPE CAPACITY  BTUhr.

INCLUDES FITTINGS PIPE SIZE

LENGTH
OF PIPE

FEET

20
40
60

1/2"

189,000
129,000
103,000

PIPE SIZE

3/4" 1"

393,000
267,000

217,000

732,000
504,000
409,000

Combustion & Ventilation Air

WARNING: Danger of property damage, bodily
injury or loss of life. The furnace and any other fuel­burning appliances must be provided with enough fresh
air for proper combustion and ventilation of flue gases.
Most homes will require that outside air be supplied into
the heated area.

The high cost of energy for home heating has brought about
new materials and methods used to construct or remodel
most current homes. The improved construction and
additional insulation has reduced the heat loss and made
these homes much tighter around windows and doors
so that infiltrated air is minimal. This creates a problem to
supply combustion and ventilation air for gas-fired or other

AIR REQUIREMENTS
The requirements for providing air for combustion and
ventilation are listed in the National Fuel Gas Code NFPA
54/ANSI Z223.1 (in Canada: CAN/CGA B149). Most homes
will require that outside air be supplied to the heated area
by means of ventilation grilles or ducts connecting directly
to the outside or spaces open to the outdoors such as attic
or crawl space. The only exception is when the furnace
area meets the requirements and definitions for an
unconfined space with adequate air infiltration.

WARNING: Danger of property damage, bodily
injury or loss of life. The furnace and any other fuel­burning appliances must be provided with enough
fresh air for proper combustion and ventilation of flue
gases. Most homes will require that outside air be
supplied into the heated area.

All air openings and connecting ducts must comply with
the following:

If the furnace is installed in an area with another gas
appliance(s), the total input rating of all appliances
must be considered when determining the free area
requirements for combustion and ventilation air openings.

Ducts must have the same cross-sectional area as the
free area of the openings to which they connect. The
minimum dimension of rectangular air ducts must not be
less than 3-inches in length or height.

VENTED ROOM HEATERS 9

INSTALLING YOUR FURNACE

LOUVERS / GRILLES AND SCREENS COVERING
FREE AREA OPENINGS

If a screen is used to cover the opening(s), it must not be
smaller than 1/4-inch mesh. Use the free area of a louver
or grille to determine the size opening required to provide
the free area specified. If the free area is not known,
assume a 20% free area for wood and a 60% free area for
metal louvers or grilles.

EXAMPLE 1
FURNACE LOCATED IN UNCONFINED SPACE.*

*An unconfined space must have a volume of a minimum
50 cubic feet per 1000 BTU/hr. of total of all appliances in
area. Adjoining rooms may be included only if there are
no doors between the rooms, or if special provisions
are made such as ventilation grilles installed between
connecting rooms.

Page 11, Figure 8 shows the minimum area in square feet’
based on 8 foot ceiling heights, required for different BTU/
hr. input ratings.

A. If your furnace is in an open area (unconfined space*)
the air that leaks through the cracks around doors
and windows may be enough for combustion and
ventilation air. The doors should not fit tight. The
cracks around windows should not be caulked or
weather stripped.

To determine if infiltration air is adequate, perform
following checks:

1. Close all doors and windows. If you have a fireplace,

start a fire and wait until flames are burning vigorously.

2. Turn on all exhausting devices, such as: kitchen and

bathroom exhaust fans, dryers (gas and electric)

3. Turn on all vented gas appliances, such as: heating

equipment (includes any room heaters), water heater

4. Wait ten (10) minutes for drafts to stabilize.

5. Check for draft hood spillage at each appliance. Hold

a lighted match 2 inches from draft opening.
See Figure 6

B. No Spillage
If the match flame pulls toward draft hood - this

indicates sufficient infiltration air:

1. Return exhausting devices and appliances to the

condition you found them.
C. Draft Hood Spills
If there is spillage at a draft hood (match goes out or

flame wavers away from draft hood):

1. Check for plugged flue connectors and chimneys.

Check and repair, stoppage and test again.

2. If you have a fireplace, open a window or door near the

fireplace and then check for spillage.
a) If spillage stops, do not use the fireplace without a

nearby window or door open until you can supply
fresh air by a permanent duct.

10 VENTED ROOM HEATERS

3. If you have kitchen and bathroom exhaust fans, turn
them off and check for spillage.

a) If spillage stops, do not use exhaust fans until you
can supply fresh air by a permanent duct.

WARNING: Danger of property damage,
bodily injury or loss of life. Draft hood spillage, with
unobstructed vents, indicates that additional air must
be brought into the structure from outside. Keep a
window open (minimum 2 inches) near the appliance
until a permanent air duct is installed.

FIGURE 6 - DRAFT HOOD SPILLAGE

VENT PIPE

DRAFT HOOD
OPENING
(match or
smoke pen)

TYPICAL WATER

HEATER

VENT PIPE

WALL

FURNACE

DRAFT HOOD
OPENING
(match or
smoke pen)

4. Spillage means air starvation and a fresh air duct or
air intakes must be installed to provide air directly
to the furnace or other gas appliance.

D. If spillage exists or when the furnace is in a building
of tight construction where the windows and doors
are weather-stripped, air for combustion and
ventilation must be obtained from outdoors or space
open to the outdoors.

Provide an opening(s) having a total free area of 1-square
inch per 4,000 BTU/hr. for the total of all appliances. The
required area is shown on page 12, Figure 11.

Figure 7 shows a typical duct going into ventilated crawl
space or attic.

1. Duct must terminate at a point not more than 1 foot
above the floor.

2. Duct size must be at least 1 inch of free area for each
4000 BTU/hr. of input of all appliances in area.

EXAMPLE 2
FURNACE LOCATED IN CONFINED SPACE

If furnace is installed in a confined space, it must be
provided with free air for proper combustion and
ventilation of flue gases by one of the following methods.

A. ALL AIR FROM INSIDE BUILDING:
If the confined space adjoins an unconfined, provide two
permanent openings, one within 12 inches of the top and
one within 12 inches of the bottom of the room connecting
directly to unconfined space. Each opening must have a
free area of at least 100 square inches or 1 square inch per
1,000 BTU/hr. combined input of appliances in one room if
combined input exceeds 100,000 BTU/hr.

WARNING: Danger of property damage, bodily
injury or loss of life. The adjoining unconfined space
must have adequate air infiltration as defined in
example 1.

Refer to figure as shown on page 11, Figure. 9, which shows
grille installation. Using the previous example, the two
connecting rooms plus the closet must equal at least 500
sq. feet to handle the combined input 50,000 plus 30,000.

FOR EXAMPLE: Your furnace is rated at 50,000 BTU/hr.
The water heater is rated at 30,000 Btu/hr. The total is
80,000 BTU/hr. You need two grilles, each with 100 square
inches of free opening. Metal grilles have about 60% free
area, so you need two metal grilles each with 160 square
inches of louvered area.

FIGURE 7  FRESH AIR DUCT

B. ALL AIR FROM OUTDOORS:

If confined space doesn’t adjoin an unconfined space then
air must be provided from outdoors or spaces open to
outdoors such as attic or crawl space.

Provide two permanent openings, one within 12 inches of
top, one within 12 inches of bottom of room connecting
directly, or by using ducts, with the outdoors or areas open
to outdoors.

If opening connects directly to, or within vertical ducts, the
free area of each opening must be at least 1 square inch
per 4,000 BTU/hr. combined input of appliances in area.

If horizontal ducts are used, the free area of each opening
must be at least 1 square inch per 2,000 BTU/hr. combined
input of appliances in area.

FOR EXAMPLE: Your furnace is rated at 50000 BTU/hr. The
water heater is rated at 30,000 BTU/hr. The total is 80,000
BTU/hr. You need two grilles, each with 20-square inches
of free opening, unless connected by horizontal ducts
which would require each grille or opening to have a free
area of 40 square inches.

Openings for inlet or outlet air should not be made into
attic area if attic is equipped with a thermostat controlled
power vent.

FIGURE 9  GRILLES CONNETING ROOMS TO MAKE
UNCONFINED SPACE

FIGURE 8  MINIMUM AREA IN SQUARE FEET

4,000 BTU/hr. PER SQUARE

INCH OPENING

ROUND

DUCT

4" DIA 3" X 3" SQ. 30,000 188

4” DIA 3” X 3” SQ. 35,000 219

4” DIA 3” X 4” SQ. 40,000 250

4” DIA 3” X 4” SQ. 45,000 281

4” DIA 3” X 5” SQ. 50,000 312

4 1/2" DIA 3” X 5” SQ. 60,000 375

* CAN BE TWO OR MORE ROOMS JOINED BY VENTILATION GRILLES.

RECTANGULAR

DUCT

MAX

BTU/hr.

INPUT

*UNCONFINED

AREA IN SQ.

FT. 8’ CEILING

SPACE MIN.

HEIGHT

VENTED ROOM HEATERS 11

INSTALLING YOUR FURNACE

FIGURE 10  AIR FROM OUTDOORS OR CRAWL SPACE

FIGURE 11  FREE AREA

FURNACE

BTU/hr. /

INPUT

30,000 7.5 7 4 2

SQ. OF

OPENING

REQUIRED NUMBER OF HOLES SILL OR

HEADER PLATES

1 1/2" 2" 3"

3. Before drilling a hole in the wall at the selected
location, drive a small finishing nail through the
ceiling in the corner of the wall and ceiling above the
thermostat location. Pull the nail out and push a small
stiff wire through the hole so it can be found in the
attic. Drill a ½-inch hole through the ceiling wall plate.

4. Probe for obstructions in the partition. Then drill a
½-inch hole through the wall at the selected location
for thermostat.

5. From the attic, feed the thermostat cable or a stiff wire
through the wall until even with the thermostat
location.

6. Snag the thermostat cable through the hole and pull
the cable through the hole in the wall so that 6
inches of the cable protrudes.

7. Route the cable to the wall heater.

8. Never use nails or staples across the thermostat wires.

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

Refer to installation instructions packed in the thermostat
carton if you have any doubt about the above procedures.
Use Williams thermostat P322016 or any millivolt
thermostat.

35,000 8.75 8 5 2

40,000 10.0 9 5 3

45,000 11.25 10 6 3

50,000 12.5 11 6 3

60,000 15.0 13 8 4

Shown in square inches - each opening (furnace only).

Based on one square inch per 4,000 BTU/hr.

Thermostat Installation (Sold Separately)

Williams’ heaters are operated by a millivolt type
thermostat. Current to the thermostat is supplied by the
pilot generator. Do not connect to electricity. Anticipator
settings are not required.

1. If an old thermostat is being replaced and is in a

satisfactory location and the wiring appears to be in good
condition, use existing wiring. If in doubt, use new wire.

2. If a new location is chosen or if this is a new

installation, thermostat cable must first be run to the
location selected. All wiring must agree with local
codes and ordinances. These instructions cover
bringing the wire down from the attic but it can be
run f rom a basement or crawl space using similar
methods.

WALLMOUNTED THERMOSTAT INSTALLATION

1. To remove the thermostat cover, squeeze both sides
and lift.

2. Connect the thermostat wires to the terminal screws
on the thermostat base. Make sure the wiring does
not interfere with thermostat operation.

3. Push any excess wire back through the hole in the wall
and plug the hole with insulation to prevent drafts from
affecting thermostat operation.

4. Being sure to level the thermostat for best
appearance, fasten the thermostat base to the wall
through the mounting holes with screws provided.

5. Replace the thermostat cover.

6. Do not run wire in any location where it might be
damaged. Avoid splicing thermostat wires unless the
spliced wires are properly cleaned, soldered and taped.

7. Use #18 gauge wire as supplied for a maximum length
of 20 feet. If longer length is needed, use #16 gauge
wire for a maximum length of 25 feet.

8. Connect the thermostat wires to the control valve as
shown in Figure 12.

CABINETMOUNTED THERMOSTAT INSTALLATION

1. Locate the knockout on the right side of the heater to
mount the thermostat. Remove the knockout by

12 VENTED ROOM HEATERS

taping lightly with a screwdriver. It will also be necessary to
cut the inside panel insulation about a ½-inch in diameter
for clearance to the knockout.

2. Cut the thermostat wire to the desired length.

3. Connect the thermostat wires to the terminal screws

on the back of the thermostat base.

4. Feed the thermostat wires through the knockout and

route through the metal clip to the gas valve. Models,
2001621A and 2001622A do not have a metal clip.

5. Mount the thermostat to the side of the cabinet with

screws provided.

6. Replace the thermostat cover.

7. Connect the thermostat wires to the control valve as

shown in Figure 12.

IMPORTANT: KEEP THE THERMOSTAT WIRE AWAY
FROM THE COMBUSTION CHAMBER.

FIGURE 12  THERMOSTAT WIRING

Vent Installation

This heater must be properly connected to a venting system. This
heater is equipped with a vent safety shutoff system to protect
against improper venting of combustion products. Tampering
with or removal of this control will void the limited warranty and
can result in carbon monoxide (CO) poisoning and possible death.

WARNING: Operation of this heater, when not
connected to a properly installed and maintained venting
system or tampering with the vent safety shutoff system, can
result in carbon monoxide (CO) poisoning and possible death.

This appliance needs fresh air for safe operation and must be
installed so there are provisions for adequate combustion and
ventilation air. This room heater is equipped with a vent safety
switch. The vent safety switch will cause gas flow to the main
burner to shutoff due to improper venting or a blocked flue. If the
vent safety switch continues to shut off the gas flow, a qualified
service person must be contacted to inspect for improper venting,
blockage in the vent pipe or the vent safety switch for being
defective.

WARNING: Do not bypass the vent safety shutoff switch.
To do so could expose the consumer to property damage,
personal injury or possible death.

FIGURE 13  CABINETMOUNTED CLEARANCE

WARNING: Danger of illness, bodily injury or death.

This heater and any other fuel burning appliance must be
provided with enough fresh air for proper combustion and
ventilation of flue gases. Most homes will require that outside
air be supplied into the heater area.

1. An effective flue is necessary to carry off water vapor,
carbon monoxide (CO), carbon dioxide (CO2), and other
products of combustion. For proper venting, follow the
following basic rules for gravity venting, which are:

a. Keep the flue gases hot.
b. Follow the vent manufacturer’s installation

instructions.
c. Select the proper vent size.
d. Provide constant fresh air replacement.

2. For new installation, it is recommended that a Type “B”
vent in accordance with its’ listing be used. A Type
“B” vent is one made of non-combustible, corrosion
resistant material of sufficient thickness, cross
sectional area and heat insulating quality to avoid
excess temperatures on adjacent combustible
material and certified by a nationally recognized
testing agency. Existing brick flues should be lined to
provide an effective vent. Brick chimneys, even in good
repair, may be too large and will not provide sufficient
draft to effectively vent a heater.

VENTED ROOM HEATERS 13

INSTALLING YOUR HEATER

3. Use vent pipe of the same size as the outlet on back

of heater. In no case should a different size vent
be used. Single wall vent pipe may be attached
directly to the draft hood of the room heater when a
clearance of 3 inches (76.2 mm) is maintained
between the single wall vent pipe and the
combustible wall of the room in which the room heater
is located. Use double wall vent pipe for clearances less
than 3 inches (76.2 mm) to combustibles.

4. Avoid a horizontal run to the vent pipe whenever

possible. When a horizontal run is necessary, the pipe
must pitch upward at least 1/4 inch per foot. It must be
supported securely and joints fastened by sheet
metal screws or rivets. Under no circumstances should
the vent run downhill.

5. Never put a damper or barometric draft control in a

gas vent pipe.

6. Never end a vent in an open attic or run a vent

through a wall to the outside without extending it
upward above the roof.

7. Always terminate the vent with an approved vent cap.

8. ALWAYS SECURE THE VENT PIPE TO THE OUTLET

ON THE BACK OF THE HEATER WITH A SHEET
METAL SCREW.

9. The flue pipe should extend through the wall of a

chimney to be flush with the inner wall.

10. The flue pipe must be adequately supported by

metal strips.

11. For the flue pipe running through walls and roofs,

use B type (1 inch (25mm) clearance to combustibles)
vent pipe.

12. Vents should extend at least 2 feet (.6m) above the

roof and above any object or nearby building within
10 feet (3m).

13. Open tees should not be used in the flue pipe.

14. The heater must not be connected to a chimney flue

that is servicing a separate solid-fuel burning appliance.

15. Run flue pipe as direct as possible with not more than

two elbows. Use 45 degree elbows if possible

16. The use of more than one appliance per vent system

may cause the vent safety shutoff device to shut
off the heater due to the cooling of vent temperatures
through the draft diverter of the second appliance.

17. The vent safety shutoff may shut down the heater if

a too large or an unlined, masonry chimney is
used. The vent may not warm quickly enough to get
adequate vent action in a chimney before the shutoff
device will shut down the heater. If this is the case, it is
recommended lining the chimney with proper size
type “B” vent pipe or type “B” chimney liner.

18. Single-wall metal pipe should not be used outdoors

in cold climates or venting gas equipment. If the vent
is installed directly outside, the cold pipe may delay
the venting and cause the heater to shut-off by the
vent safety switch. To prevent this problem, as well
as condensation of flue products, an insulated

14 VENTED ROOM HEATERS

enclosure is recommended. Use type B, vent pipe and
maintain at least a one inch clearance to combustibles.
Use a metal thimble to protect vent pipe as it passes
through combustibles.

IMPORTANT: Inspect venting system prior to each
heating season.

Typical Methods of Safely Venting
Your Heater

1. Any horizontal run of vent pipe must slope upward a
minimum of 1/4" per foot. Secure all joints of the vent
with sheet metal screws.

2. Where the vent passes through the ceiling or wall, a
thimble is required to keep the ceiling from catching
fire. Use only a thimble designed for use with Type “B”
gas vent, certified by a nationally recognized testing
agency.

3. The vertical (straight up and down) part of the vent
must end 2 feet above any part of the roof within 10 feet
of the vent. This is to make sure the “draw” of the vent
is not obstructed in any way.

4. A vent cap, approved by a nationally recognized
testing agency, must be installed on top of the vent to
keep out rain and snow and to prevent obstructions of
the vent. The vent cap will also prevent excessive
downdraft that can cause carbon monoxide to enter
into the home. Do not use a homemade vent cap.
They are dangerous and can restrict the draft of the vent.

5. Safe clearances are shown below. To prevent a fire,
make sure the heater is installed no closer than the
distances shown in the figures that apply to your type
of venting.

6. If you are venting into a masonry chimney, it must be
lined, in good repair and must not serve a wood or
coal burning appliance. The flue must be at least as
large in diameter as the vent connector. The top of
the chimney must be two (2) feet higher above
any part of the roof within ten (10) feet horizontally
of the chimney and must be three (3) feet higher than
the point where it passes through the roof line. If
installed in front of a fireplace, the pipe must pass
through a sheet metal cover on the fireplace that fits tightly.

VENTED ROOM HEATERS VENT SIZE INCHES

NATURAL GAS PROPANE GAS VENT SIZE INCHES

2001622A 2001621A 3

350522A 3501521A 4

5001522A 5001521A 4

6501522A 6501521A 5

3502522A 3502521A 4

5002522A 5002521A 4

6502522A 6502521A 5

FIGURE 14  VENTING INTO A MASONRY CHIMNEY

FIGURE 16  VENTING INTO AN OUTSIDE
TYPE “B” GAS VENT

FIGURE 16 B  ALTERNATE VENTING

FIGURE 15  STRAIGHT UP VENTING WITH
TYPE “B” GAS VENT

VENTED ROOM HEATERS 15

OPERATING YOUR HEATER

Start-Up Procedure

Start the heater using the procedures in the section
“Operating Your Heater”.

WARNING: Danger of bodily injury or death.
propane gas is heavier than air and it will settle in
any low area, including open depressions and it will
remain there unless the area is ventilated.

Never attempt to start-up the unit before thoroughly
ventilating the area.

Check the heater operation as outlined in the following
instructions. If any sparking, odors or unusual noises are
encountered, shut off the electric power immediately.
Recheck for wiring errors or obstructions in or near the
fan motor.

CHECK GAS INPUT AND PRESSURES
For heaters located at elevations between sea level and
2,000 feet, the measured input must not be greater than
the input shown on the rating plate of the heater. For
elevations above 2,000 feet, the measured input must not
exceed the input on the rating plate reduced by 4 percent
for each 1,000 feet that the heater is above sea level.

Gas supply pressure and manifold pressure with the
burners operating is specified on the rating plate.

TYPE OF GAS MANIFOLD PRESSURE, IN. W.C.

NATURAL 4.0"

PROPANE 10.0"

Rated input will be obtained on a heating value of 2,500
BTU/hr. for propane at 10-inches manifold pressure with
factory-sized orifices. If propane gas having a different
heating value is supplied, orifices must be changed by a
qualified service technician before the heater is operated.

CHECK THE GAS INPUT (NATURAL GAS ONLY)

WARNING: Natural gas heating value (BTU per

cubic foot) can vary significantly. Therefore, it is the
installer’s responsibility to see that BTU/hr. input to
the heater is adjusted properly. Failure to do so could
cause combustion chamber failure, asphyxiation,
fire or explosion resulting in damage, bodily injury or
death. Refer to the National Fuel Gas Code (NFPA 54)
to be sure the heater is burning fuel at the proper rate.

Under firing could cause inadequate heat, excessive
condensation or ignition problems. Over firing could
cause sooting, flame impingement or overheating of the
combustion chamber.

Before starting natural gas input check, obtain heating
value of the gas (BTU per cubic foot) at standard
conditions from your local supplier.

To measure the input, using the gas meter, proceed as
follows:

1. Turn off gas supply to all other appliances except
the heater.

2. With the heater operating, time the smallest dial on
the meter for one complete revolution. If this is a
2-cubic-foot dial, divide the seconds by 2. If this is a
1-cubic-foot dial, use the time in seconds as is
(3,600 = Sec/hr.). This gives the seconds per cubic foot
of gas being delivered to the heater.

3. Assuming natural gas with a heating value of 1,000
BTU per cubic foot and 34-seconds per cubic foot used
as determined by step (2), then:

Input = 1,000 x 3,600 / 34 = 106,000 BTU/hr.
This measured input must not be greater than the

input indicated on the nameplate of the heater.

4. Relight all other appliances turned off in Step 1 above.
Be sure all pilots are operating.

CHECK THERMOSTAT
Check the thermostat operation. When set above room
temperature shown on the thermostat, the main burner
should light. Make certain the thermostat turns off the
heater when the room temperature reaches the selected
setting and starts the heater when the room temperature
falls a few degrees.

CHECK THE MANIFOLD GAS PRESSURE
A tapped opening is provided in the gas valve to facilitate
measuring the manifold gas pressure. A “U Tube”
manometer having a scale range from 0 to 12-inches of
water should be used for this measurement. The manifold
pressure must be measured with the burner and pilot
operating. Any major changes in flow must be made by
changing the size of the burner orifice.

Check with your local gas supplier for proper orifice sizing.

CHECK PILOT BURNER
The pilot flame must envelop 1/2- to 5/8-inches of the
generator. Pilot flame is preset at the factory, so ordinarily
does not require field adjustment. Figure 17 On new
installations, the gas lines will be filled with air and may
take several minutes to establish a pilot flame.

FIGURE 17  PILOT BURNER

16 VENTED ROOM HEATERS

FIGURE 18  BURNER FLAME CHARACTERISTICS

BURNER FLAME CHARACTERISTICS

Start the heater and let it operate for at least 10 minutes.
Open the access door to view the burner flame. Limit your
movements near the heater a few more minutes before
making your final observation. The flame may look yellow
due to dust particles in the room air. The flame should
change to a nice blue color with firm inner and secondary
cones. An occasional flash of orange might be seen as
dust particles burn in the flame. This is normal. No burner
adjustment is provided, or is necessary. (Figure 18).

NORMAL APPEARANCE
NATURAL GAS:

1. Inner cone- blue color - 3/8 to 5/8-inch above ports.

2. Secondary inner cone - light blue - 1 to 2-inches

above ports.

3. Total flame - from blue to nearly invisible -

approximately 6-inches above ports.

PROPANE GAS:

1. Inner cone - blue color - 1/2 to 3/4-inch above ports.

2. Secondary inner cone - light blue - 1 to 2-inches

above ports.

3. Total flame - from blue to nearly invisible -

approximately 6-inches above ports.

ABNORMAL APPEARANCE
LAZY FLAME:

Long soft yellow cones moving around in the combustion
chamber lifting from ports (insufficient air).

EXTREMELY FAST FLAME:
Will not hold to ports - entire cone sections blow off from
noisy ports (too much pressure).

WARNING: If the flame appears abnormal,
contact the gas company or a qualified service
technician immediately.

WARNING: Natural gas heating value (BTU per
cubic foot) can vary significantly; therefore, it is the
installer’s responsibility to see that the BTU input to
the heater is adjusted properly. Failure to do so could
cause combustion chamber failure, asphyxiation, fire or
explosion, resulting in property damage, bodily injury or
death. Refer to the National Fuel Code (NFPA-54) to be
sure the heater is burning fuel at the proper rate.

WARNING: Read owner’s manual before using /
installing. Be sure CHANGED LIGHTING INSTRUCTION
TAG hangs at the lowest position in the furnaces
under / below the heat shield.

GAS CONVERSION KITS

NATURAL TO PROPANE GAS

MODEL DESCRIPTION

8945 200 SERIES
8946 350 SERIES
8947 500 SERIES
8948 650 SERIES

PROPANE TO NATURAL GAS

MODEL DESCRIPTION

8949 200 SERIES
8950 350 SERIES
8951 500 SERIES
8952 650 SERIES

For Your SAFETY,
read before lighting

WARNING: If you do not follow these instructions
exactly, a fire or explosion may result causing property
damage, personal injury or loss of life.

A. This appliance has a pilot which must be lighted by
hand. When lighting the pilot, follow these
Instructions exactly.

B. BEFORE LIGHTING smell around the appliance area
for gas. Be sure to smell next to the floor because
some gas is heavier than air and will settle on the floor.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance or strike a match.

• Do not touch any electric switch; do not use any
phone or cell 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.

VENTED ROOM HEATERS 17

OPERATING YOUR HEATER

C. Use only your hand to push in or turn the gas control
knob. Never use tools. If the knob will not push in or
turn by hand, don’t try to repair it, call a qualified
service technician. Force or attempted repair may
result in a fire or explosion.

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

NOTE: FOR ADDITIONAL INFORMATION REFER TO THE
INSTALLATION AND OPERATION INSTRUCTION MANUAL
SUPPLIED WITH THIS APPLIANCE OR CONTACT THE
MANUFACTURER IDENTIFYING THE PRODUCT BY ITS
MODEL NUMBER LOCATED ON THE RATING PLATE,
FOUND NEAR THE GAS VALVE.

Operating Instructions

1. STOP! Read the safety information above.

2. Set the thermostat to the lowest setting.

3. If applicable, turn off all electric power to the appliance.

4. Remove the control access panel.

5. Turn the gas control knob clockwise to “OFF”.

• If the pilot will not stay lit after several tries, turn the
gas control knob to “OFF” and call your service
technician or gas supplier.

11. Close the pilot observation door and tighten the wing
nut (if equipped).

12. Turn the gas control knob counterclockwise to “ON”.

13. Replace the control access panel.

14. Turn on all electric power to the appliance.

15. Set the thermostat to the desired setting.

To turn OFF GAS to appliance

1. Set the thermostat to the lowest setting.

2. Turn off all electric power to the appliance if service is
to be performed.

3. Remove the control access panel.

4. Push in the gas control knob slightly and
turn it clockwise to “OFF”. Do not Force.

5. Replace the control access panel.

IMPORTANT: KEEP BURNER AND CONTROL
COMPARTMENT CLEAN.

FOR YOUR SAFETY READ BEFORE LIGHTING

NOTE: Knob cannot be turned from “PILOT” to “OFF”

unless knob is pushed in slightly. Do not use force.

6. Wait five (5) minutes to clear out any gas, then smell for

gas, including near the floor. If you then smell gas,
stop! Follow “B” In the safety information above. If you
don’t smell gas, go to the next step.

7. Loosen wing nut and open the pilot observation door

(If equipped).

8. To find the pilot, follow the metal tube from the gas

control valve. The pilot is mounted on
the side of the burner.

9. Turn knob on the gas control

counterclockwise to “PILOT.”

10. Push in the control knob all the

way and hold in. Immediately light the pilot.
Continue to hold the control knob in for about one
(1) minute after the pilot is lit. Release the knob and it
will pop back up. The pilot should remain lit. If it goes
out, repeat Steps 5 through 10.

• If the button does not pop up when released, stop and

immediately call your service technician or
gas supplier.

18 VENTED ROOM HEATERS

OPERATING INSTRUCTIONS

TO TURN OFF GAS TO APPLIANCE

Read owner’s manual before using/installing. Be sure CHAINED LIGHTING INSTRUCTION TAG

hangs at the lowest position in the furnace under/below the heat shield.

CARING FOR YOUR HEATER

WARNING: DUE TO HIGH SURFACE
TEMPERATURES - KEEP CHILDREN, CLOTHING,
FURNITURE OR ANY COMBUSTIBLE MATERIAL AWAY
FROM THE HEATER. Make sure the “FOR YOUR SAFETY”
hang tag (see below) hangs below the heat shield.

How To Care For Your Heater

WARNING: Danger of bodily injury or death. Turn
off electric power supply at the disconnect switch, fuse
box or service panel before removing any doors or
access or service panels from the unit.

ANNUAL UPKEEP NEEDED
It is recommended that a qualified service technician
perform these checks at the beginning of each heating
season.

CABINET FINISH
Clean the cabinet with a damp rag. Never use abrasive
cleaners. Cabinets are finished in heat resistant powder
coated finish - DO NOT refinish with wall paint.

HEATER AREA
Keep the area near the heater clear and free from
combustible materials, gasoline and other flammable
liquids and vapors.

COMBUSTION AND VENTILATION AIR
The combustion and ventilation air supply must not be
blocked.

Do not put anything in or on the heater cabinet.
For better circulation and more effective heating, do not

place obstructions, furniture or other items closer than four
feet to the front of the cabinet or two feet from each side
of the cabinet.

CLEANING BLOWER (IF EQUIPPED)
Shut off electricity. Clean any lint or dirt from fan blades,
fan motor and exposed air passages. Annually put two
drops of SAE 20 oil in each of the two cups or oil tubes.

PILOT BURNER
Light the pilot using the instructions in OPERATING YOUR
HEATER. Leave the thermostat at the lowest setting.

The pilot flame should surround 1/2 to 5/8 inches of the
generator tip. If the flame needs adjusting, do it as follows:

REMOVABLE CABINET TOP
350, 500, & 650 MODEL SERIES

For ease of cleaning, access or replacement of internal
parts, the top of this heater can be removed by following
these steps:

1. Remove the three (3) brackets on the rear of the heater

securing the cabinet top to the back plate.

2. Pull the cabinet top forward and lift up. Reinstall the

cabinet top by reversing the procedures noted above.
Figure 19

NOTE: Take special care to engage the six (6) clips located
on the bottom of the cabinet top into the top flange of the
heater sides.

FIGURE 19  REMOVABLE CABINET TOP

ADJUST PILOT BURNER

1. Insert a small screwdriver, adjust the flame as needed.
Turn the screw counterclockwise to increase the flame,
clockwise to decrease.

2. Turn the thermostat to the highest setting. The main
burners should light quickly and smoothly. Turn the
thermostat to its lowest setting. Main burners should
go out. The pilot should remain lit.

3. Refer to Figure 20.

VENTING SYSTEM
Make sure that no parts of the vent air system are
blocked, rusted or damaged. Clean or replace before
using the heater.

BURNER CLEANING
Check the burner. If cleaning is required, contact a
qualified service technician to clean and service burner.

FIGURE 20  PILOT ADJUSTMENT SCREW

VENTED ROOM HEATERS 19

CARING FOR YOUR HEATER

Cleaning burner compartment

Because cold air is attracted to the flame during heater
operation, a build up of lint from carpeting, bedding, dust,
etc. in the burner area will occur. It is necessary to clean
this area regularly. Use a vacuum cleaner with a narrow
attachment to reach small areas. Be careful in and around
the pilot. A change in its adjustment could be made if
moved during cleaning.

DANGER: A build up of any dust, lint or foreign material in
the primary air opening of the burner can interfere with the
proper air gas mixture and can result in a yellow flame which
can produce carbon monoxide and soot. This condition if
allowed to develop, can lead to bodily injury including death. It
is imperative that the burner be kept clean.

TO REMOVE LOGS FROM COMBUSTION CHAMBER
Always remove the logs from the combustion chamber when
cleaning the burner or combustion chamber.

1. As parts are removed, place them in a safe place until

ready for reassembly.

2. Remove the chrome hearth assembly. Compression clips

hold hearth assembly in place. Grasp the assembly frame
and pull forward.

3. Remove the screws in the glass window frame.

FIGURE 21  LOG MOUNTING

IMPORTANT: The logs are made of special lightweight

materials that can be easily damaged by rough handling.

4. Lift the front log up and out of the front log support

brackets carefully. Take care when pulling it out through
the window opening. Do not scrape it against the metal
edges of the opening.

5. Remove the screws and plates holding the top right

and the top left sides of the rear log set against the top
rear support brackets.

6. Lift the rear log set up and out of the bottom support

brackets. Tilt the top towards the back and slowly allow
the bottom to pass through the opening first. Take care
not to scrape it against the metal edges of the opening.

7. Reverse the above procedure to reassemble after cleaning.

GLASS CLEANING
Use mild soap and water only. Never clean when the glass
is hot.

If the glass is broken it must be replaced with the
manufacturer’s authorized part only. Failure to do so could
cause property damage, bodily injury or death.

NOTE: A properly adjusted burner with nearly all gases
will produce a flame which has a clear blue cone having
a bluish-red or bluish-violet outer mantle.

20 VENTED ROOM HEATERS

INSTALLATIONS IN THE STATE
OF MASSACHUSETTS

All installations in the State of Massachusetts must use
the following requirements when installing, maintaining
or operating direct-vent propane or natural gas-fired
space heaters.

For direct-vent appliances, mechanical-vent heating
appliances or domestic hot water equipment, where the
bottom of the vent terminal and the air intake is installed
below four feet above grade the following requirements
must be satisfied:

1. If there is not one already present, on each floor level

where there are bedroom(s), a carbon monoxide
detector and alarm shall be placed in the living area
outside the bedroom(s). The carbon monoxide detector
shall comply with NFPA 720 (2005 Edition).

2. A carbon monoxide detector shall be located in the

room that houses the appliance or equipment and shall:
a. Be powered by the same electrical circuit as the
appliance or equipment such that only one
service switch services both the appliance and the
carbon monoxide detector.
b. Have battery back-up power;

c. Meet ANSI/UL 2034 Standards and comply with
NFPA 720 (2005 Edition); and
d. Have been approved and listed by a Nationally
Recognized Testing Laboratory as recognized under
527 CMR.

A CARBON MONOXIDE DETECTOR SHALL:

a. Be located in the room that houses the appliance or
equipment;
b. Be either hard-wired or battery powered or both; and
c. Shall comply with NFPA 720 (2005 Edition).

3. A product-approved vent terminal must be used,
and if applicable, a product-approved air intake must
be used. Installation shall be in strict compliance with
the manufacturer’s instructions. A copy of the installation
instructions shall remain with the appliance or
equipment at the completion of the installation.

4. A metal or plastic identification plate shall be mounted
at the exterior of the building, four feet directly above
the location of vent terminal. The plate shall be of
sufficient size to be easily read from a distance of
eight feet away, and read “Gas Vent Directly Below”.

HINTS AND INFORMATION

If your furnace fails to work correctly, you may avoid the
inconvenience and cost of a service call by checking the
troubleshooting section on page 30 before you call
for service.

WARNING: If the information in this manual is not
followed exactly, a fire or explosion may result causing
property damage, personal injury or loss of life.

DO NOT store or use gasoline or other flammable vapors
and liquids in the vicinity or this or any other appliance.

HOW TO ORDER REPAIR PARTS

When ordering repair parts, always give the following
Information:

1. MODEL NUMBER

2. MFG. DATE CODE

3. PART NUMBER

4. PART DESCRIPTION
All parts listed herein may be ordered from your equipment

supplier. The model number of your Williams wall furnace
will be found on the nameplate near gas valve, inside control
compartment.

WHAT TO DO IF YOU SMELL GAS

• Open all of the windows.

• Do not try to light any appliance.

• Do not touch any electrical switch.

• Do not use any phone or cell phone in your building.

• Extinguish any open flame.

• Immediately call your gas supplier from a neighbor’s
phone. If you cannot reach your gas supplier, call the fire
department.

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

VENTED ROOM HEATERS 21

BLOWER ACCESSORY 2102

Mounting the Blower

Note: All electrical work must conform to your local
codes and ordinances or in their absence, with National
Electrical Code, ANSI/NFPA 70. If you are not familiar with
wiring codes in general, have a competent electrician do
this job. In CANADA: CANADIAN ELECTRICAL CODE C22.1.

WARNING: Danger of property damage, bodily
injury or death. Turn off electrical power supply at
disconnect switch, fuse box or service panel before
removing or working on fan.

1. Place the motor and blower on the heater floor,

securing with four (4) screws. Attach three (3)
screws to the inlet duct and one (1) screw to the
heater floor, using the existing screw holes. Align
the opening in the base of the motor and blower with
the opening in the heater floor. The opening on the
side of the motor and blower should align with the
opening on the heater inlet duct.

2. Attach the “HI” and “LO” speed switch to the upper

left corner on the back of the heater and replace the
corner bracket with the speed switch plate using the
existing mounting holes. The correct position for the
fan switch is shown below. The top of the fan switch
should be level with the notch directly across the
switch on the blower mounting plate. Make sure
speed switch wires are secured with clamp (provided
in the kit) away from the combustion chamber before
operating the heater.

WIRING

CORRECT
POSITION

OF FAN

SWITCH

RUN

SWITCH

WIRE

THROUGH

ATTACHED

CLAMP

ATTACH CLAMP TO SECURE WIRES

OPERATION
This accessory is operated using the factory equipped, three­prong (grounding) plug and cord. When using the plug
and cord, for your protection against shock hazard, it must
be plugged directly into a properly grounded three-prong
receptacle. DO NOT CUT OR REMOVE THE PRONG.

You must select “HI” or “LO” on the speed switch (item 8) for
automatic blower operation. When the heater heats up, the
fan switch is activated and the blower will operate. When the
heater cools down, the blower will turn off. The blower will
not operate if the speed switch is set in the “OFF” (center)
position.

AIR INLET
DUCT

22 VENTED ROOM HEATERS

FURNACE ACCESSORY REPLACEMENT PARTS
200 MODELS

MODEL NUMBERS

2001622A 2001621A

REF.

NO.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

REPLACEMENT PART DESCRIPTION 2001622A 2001621A

Wrapper Assembly K000275 K000275

Draft Diverter Assembly K000274 K000274

Combustion Chamber 8957 8957

Base Plate K000265 K000265

Valve Bracket K000850 K000850

Control Valve P323011 P322660

Burner K000851 K000851

Orifice Fitting (2) P500086 P500086

Burner Orifice P501781 P501800

Pilot P323074 P323073

Thermocouple P043800 P043800

Igniter Bracket 7A189 7A189

Vent Safety Switch P323663 P323663

Wire Assembly P500409 P500409

Manual Spark Igniter P285500 P285500

16

17

Manifold Plate K000852 K000852

Manifold Assembly P323681 P323681

Thermostat not included with these models.

VENTED ROOM HEATERS 23

EXPLODED VIEW & REPLACEMENT PARTS

15

13

2

3

8

12

6

14

16

5

4

11

10

1

7

9

8

17

24 VENTED ROOM HEATERS

FURNACE ACCESSORY REPLACEMENT PARTS
350  500  650 MODELS

MODEL NUMBERS

NATURAL

3501522A 3501922A 5001522A 5001922A 6501522A 6501922A

PROPANE

3501521A 3501921A 5001521A 5001921A 6501521A 6501921A

REF.

NO.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

REPLACEMENT PART
DESCRIPTION

Panel Side Right

Inlet Duct

Bottom Louver Assembly

Center Panel

Cabinet Bottom

Panel Side Left

Wire Assembly

Top Louver Assembly

Combustion Chamber

Burner

Cabinet Top

Control Bracket

Orifice

Orifice Fitting

Manifold Assembly

3501522A
3501922A

K000204 K000204

K7000-6022 K7000-6022

K000182-1 K000182-1

K000220 K000220

K5000-6003 K5000-6003

K000207 K000207

P500409 P500409

K000181 K000181

8958 8958

P501620 P501620

K000223 K000223

K000147 K000147

P500336 P500351

P500086

P323678

3501521A
3501921A

P500086

P323678

5001522A
5001922A

K000205 K000205

K7000-6022 K7000-6022

K000182-2 K000182-2

K000221 K000221

K5000-6004 K5000-6004

K000208 K000208

P500416 P500416

K000212-1 K000212-1

8960 8960

P501621 P501621

K000224 K000224

K000147 K000147

P500330 P500330

P500086

P323679

5001521A
5001921A

P500086 P500086 P500086

P323679 P323680 P323680

6501522A
6501922A

K000206 K000206

K7000-6022 K7000-6022

K000182-3 K000182-3

K000222 K000222

K5000-6019 K5000-6019

K000209 K000209

P500416 P500416

K000212-2 K000212-2

8962 8962

P501622 P501622

K000225 K000225

K000147 K000147

P500327 P500327

6501521A
6501921A

16

17

18

19

20

21

22

23

24

25

Gas Control Valve

Thermocouple

Shield Cover

Pilot

Vent Safety Switch

Hear Shield (Rear)

Back Plate

Rear Corner race

Bracket

Manual Spark Igniter

P323011

P043801 P043801

– –

P323074 P323073

P323663 P323663

K7003-6370 K7003-6370

K000309 K000309

K7003-6097 K7003-6097

7A189 7A189

P285500 P285500

Thermostat not included with these models.

P322660

P323011

P043801 P043801

K7011-6030 K0711-6030

P323074 P323073

P323664 P323664

K7003-6371 K7003-6371

K000310 K000310

K7003-6097 K7003-6097

7A189 7A189

P285500 P285500

P322660 P323011 P322660

P043801 P043801

– –

P323074 P323073

P323664 P323664

K7003-6372 K7003-6372

K000526 K000526

K700-6097 K700-6097

7A189 7A189

P285500 P285500

VENTED ROOM HEATERS 25

EXPLODED VIEW & REPLACEMENT PARTS

11

8

20

21

18

7

22

6

2

4

9

16

25

24

12

13

19

14

17

10

23

1

15

26 VENTED ROOM HEATERS

5

3

BLOWER ACCESSORY KIT 2102
FOR 350  500  650 MODELS

MODEL NUMBERS

3501522A 3501922A 3501521A 3501921A

3502522A 3502922A 3502521A 3502921A

5001522A 5001922A 5001521A 5001921A

5002522A 5002922A 5002521A 5002921A

6501522A 6501922A 6501521A 6501921A

652522A 6502922A 6502521A 6502921A

REF.

NO.

1

2

3

4

5

6

7

8

9

10

Not

Shown

Not

Shown

REPLACEMENT PART DESCRIPTION PART NUMBER

Motor P501779

Fan Switch P323096

Fan Switch Plate K000862

Junction Box 90-01005-000-02

Cord and Plug P501778

Wire (Red) P202900

Wire (Black) P202800

Wire (Blue) P202700

Speed Switch Plate K000862

Speed Switch P320911A

Switch Mounting Bracket – 500 Series K000868

Switch Mounting Bracket – 650 Series K000870

VENTED ROOM HEATERS 27

EXPLODED VIEW & REPLACEMENT PARTS

1

2

4

3

5

LLOO

OFFOFF

HIHI

10

9

7

8

6

28 VENTED ROOM HEATERS

TROUBLESHOOTING YOUR FURNACE

For qualified service technicians.

ISSUE

1. Pilot will not stay lit
after following
lighting instructions.

2. Pilot burning - no gas
to the main burner.

3. Burner comes “ON” but
goes OFF before blower
turns ON.

POSSIBLE CAUSE(S)

A. Generator producing
insufficient millivolts.

B. Loose or dirty generator
connections at gas valve.

C. Generator defective.

D. Grounded thermostat wire.

E. Defective valve.

A. Thermostat not turned to a
position calling for heat.

B. Plugged burner orifice.
C. Improperly wired or broken

thermostat wires.
Defective thermostat.

D. Pilot generator may not be
generating sufficient
millivoltage to open valve.

E. Defective valve.

A. Thermostat location.

B. Defective thermostat.

CORRECTIVE ACTION

Check pilot flame – it must impinge on the generator from 1/4 to 3/8-inches .
Be sure the thermocouple is fully inserted in its bracket.

Clean and/or tighten the connections at the valve.

Check the generator with millivolt meter. Take reading at the generator
terminals of the valve with the valve placed in “Pilot” position. Disconnect the
thermostat wires. The millivolt reading should be 450 millivolts or more.

Remove the thermostat wires from the valve terminals. If the pilot now stays
lit, trace the thermostat wiring circuit for a ground. May be grounded to
heater, gas supply, nails or staples.

Replace the gas valve after above is verified.

Set the thermostat to a position calling for heat.

Clean or replace.
Check the connections at valve terminals. If valve operates, check the

thermostat wires.

See 1A and 1C above.

Replace.

Check the thermostat location. It should not be in the path of warm air
discharge from heater, near a lamp, or above a T.V. or stereo.

Check the thermostat calibration or replace.

4. Heater not producing
sufficient heat.

5. Heater operates, but
will not shut off after room
temperature is attained.

6. Pilot outage.

7. Main burner will
not stay on.

A. Heater may be too small for
space being heated.

B. Heater not burning at full rate.

A. Thermostat wiring defective.

B. Thermostat location.

C. Defective thermostat.
D. Valve stuck open.

A. Pilot flame may be too low or
blowing (high), causing pilot
to drop out.

B. Drafts or drafty areas.

A. Blockage in vent pipe.
B. Thermostat location.

C. Restriction in vent system
caused by offsets.

Check heat sizing calculations.

Check for low gas pressure at gas valve. It should be 4 inches W.C. for Natural
Gas; 10.5 inches W.C. for propane gas Check for blocked burner orifice.

Thermostat lead wires may be shorted together, caused by a nail or staple.
Check by removing thermostat leads from valve terminals.

Check thermostat location. If on an outside wall, or there is a hole in the wall
behind thermostat, cold air may be coming in contact with the thermostat.
Relocate the thermostat or plug the hole.

Verify thermostat temperature reading or replace.
Replace valve.

Adjust pilot flame. Pilot orifice may be plugged
(Check for spider webs or other material).

Check for doorway and high air movement areas.

Checks vent pipe for blockage, such as bird nests, twigs, leaves, etc.
Check thermostat location - if on an outside wall or there is a hole in wall

behind the thermostat causing cold air to contact the thermostat, relocate
the thermostat or plug the hole.
Check that the vent cap is properly installed, and not placed too far down on
the vent pipe. Cap must be the same manufacturer as the vent.

All type “B” vents shall extend in a vertical direction with no more than two
offsets not exceeding 45 degrees. Any angle greater than 45 degrees from
vertical is considered horizontal. Any offsets used should be as far above

VENTED ROOM HEATERS 29

ISSUE

POSSIBLE CAUSE(S)

CORRECTIVE ACTION

8. Abnormal operation.

9. Noisy blower.

D. Incorrect vent pipe.

E. Loose connections on the
vent safety wiring harness.

A. Delayed ignition - pilot
flame may be too low.

B. Expansion noise, ticking.

C. Combustible gas spillage.

D. Excessive flame roll-out.
E. Burner is over-fired.

F. Yellow burner flame.
G. Yellow pilot flame.

A. Housing rattling.
B. Blower dirty.
C. Blower wheel bent.

the draft hood as possible to allow venting to begin before any restriction is
encountered. The use of too many offsets may also prevent proper venting.

Use listed B/W type vent pipe. DO NOT use transite or any other type of
ceramic pipe for venting. DO NOT use single wall pipe. When venting into
a masonry chimney, the chimney must be properly lined and sized for this
gas heater. The use of type “B” or flexible chimney liner is recommended.

Check the connection on both the switch and the gas valve. Tighten if
necessary.

Adjust pilot flame. Refer to “How to Care for Your Heater” section in this
manual.

Heater may be distorted by being vented through an uneven opening. A
restricted vent may create expansion noise. Refer to “Venting” section of
this manual.

Check vent system for a blocked flue, excessive down draft (wind) or
negative pressure in room caused by ventilating fan or a fire in a fireplace.

Heater is possibly overrated - check for high gas pressure at gas valve (see 4B)
Check the manifold gas pressure. Check the rate, this appliance is

manufactured for elevations up to 2,000 feet. It must be derated for
operation above 2,000 feet.

Check burner for obstructions. Install new burner and pilot orifices.
Remove pilot orifice, check and clean.

Tighten blower screws.
Clean blower wheel.
Straighten or replace.

.

10. Blower does not run.

A. Fan switch not set.
B. Check bearings.

Select fan speed.
Add oil as outlined in “Blower Accessory Instructions”.

30 VENTED ROOM HEATERS

SERVICE RECORD

DATE MAINTENANCE PERFORMED COMPONENTS REQUIRED

VENTED ROOM HEATERS 31

TM

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