Williams 743511 Installation instructions

Installation Instructions and Owner’s Manual
Direct-Vent Wall Furnace
- Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
- WHAT TO DO IF YOU SMELL GAS
• Open all windows.
• Do not try to light any appliance.
• Do not touch any electrical switch.
• Do not use any 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 your gas supplier,
call the fire department.
- Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.
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.
Williams Furnace Co., 250 West Laurel Street, Colton, CA 92324 U.S.A.
MODEL:
Natural Gas Only
0743512
MODEL:
Propane Gas Only
0743511
WARNING: Improper installation, adjustment,
alteration, service, or maintenance can cause
injury or property damage. Refer to this
manual. For assistance or additional
information, consult a qualified installer,
service agency or the gas supplier.
WARNING: Installation and repair must be
done by a qualified service person. The
furnace should be inspected before use and at
least annually by a professional service
person.
WARNING: If not installed, operated and
maintained in accordance with the
manufacturer’s instructions, this
product could expose you to substances in
fuel or from fuel combustion which can cause
death or serious illness and which are known
to cause cancer, birth defects or other
re
p
roductive harm.

Table of Contents
General Information and Technical Data
Instructions to Installer ………………………………………………………………………….……….................………… 1
Safety and General Warnings ………………………………………………………………….…………………...………... 2
Technical Data ……………………………………………………………………………………….…………...……………. 3
Installation
Wall Installation ………………………………………………………………………………………………………………… 4
Outside Location for Vent Terminal ……………………………………………………………………………….…………. 5
Gas Supply ………………………………………………………………………………………………………….………….. 7
Operating Instructions
Operating Instructions …………………………………………………………………………………………….………….. 9
Servicing
Checking and Adjusting the Gas Manifold Pressure ………………………………………………………………….…. 10
Checking, Removing and Reassembling of the Vent – Air Intake System ………………………………………….…. 10
Lubrication of Moving Parts ……………………………………………………………………………………………….… 10
Flame Visual Check ……………………………………………………………………………………………………….…. 10
Replacement Parts ………………………………………………………………………………………………………….… 11
General Information and Technical Data
This furnace is design certified to ANSI Z21.86-2004 / CSA 2.32-2004 Gas–Fired Gravity and Fan-Type, Direct-Vent Wall
Furnaces as a Fan-Type Direct-Vent Wall Furnace to be installed on an outside wall according to these instructions.
Any alteration of the original design, installed other than as shown in these instructions or used with a type of gas not
shown on the rating plate is not permitted.
Instructions to Installer
Installation and repair should be done by a QUALIFIED SERVICE TECHNICIAN.
The installation must conform to local codes or in the absence of local codes; the installation must conform to the National Fuel
Gas Code ANSI Z223.1/NFPA 54, Natural Gas and Propane Installation Code CSA B149.1.
Mobile (Manufactured) home installations must conform with the “Manufactured Home Construction and Safety Standard Title 24
CFR, Part 3280” or, when such a standard is not applicable, the Standard for Manufactured Home Installations, ANSI A 225.1
NFPA/501A, Mobile Home Standard, CAN/CSA Z240 MH Series, in Canada. Installer must leave instruction manual with home
owner after installation. Installer must show home owner how to start and operate furnace and thermostat. Installer must
provide a 1/8-inch NPT plugged tapping for test gauge connection immediately upstream of the gas supply connection of the
furnace.
During initial firing of the furnace, residual manufacturing grease will bake out and smoke will occur which is not a health danger.
To prevent nuisance and operation of fire alarms, ventilate the room for the first two hours of operation.
WARNING: Any change to this furnace or its controls can be dangerous. This is a heating appliance and any
panel, door or guard removed for servicing this furnace must be replaced prior to operating the furnace.
1

Safety Rules and General Warnings
DO NOT OPERATE THIS FURNACE WITHOUT FRONT PANEL INSTALLED
•Due to high temperatures, the furnace should be
located out of traffic and away from furniture and
draperies.
•Children and adults should be alerted to the
hazards of high surface temperatures and should
stay away to avoid burns or clothing ignition.
•Young children should be carefully supervised
when they are in the same room as the furnace.
•Clothing or other flammable material should not be
placed on or near the furnace.
•Any safety screen or guard removed for servicing
an furnace must be replaced prior to operating the
furnace.
•Keep burner and control compartment clean.
•The outside vent cap is hot while furnace is in
operation.
•Installation and repair should be done by a
QUALIFIED SERVICE TECHNICIAN. The furnace
should be inspected before use and at least
annually by a qualified service technician.
•More frequent cleaning may be required due to excessive
lint from carpeting, bedding materials, etc. It is imperative
that control compartments, burners and circulating air
passageways of the furnace be kept clean.
•DO NOT put anything around the furnace that will obstruct
the flow of combustion and ventilation air.
•DO keep the furnace area clear and free from combustible
materials, gasoline and other flammable vapors and
liquids.
•DO examine venting system periodically and replace
damaged parts.
•DO examine burner periodically. Clean and replace
damaged parts.
•DO NOT use this furnace if any part has been under water.
Immediately call a qualified service technician to inspect
the furnace and to replace any part of the control system
and any gas control which has been under water.
Safety Information for Users of LP Gas
Propane (LP Gas) is a flammable gas which can cause fires and explosions. In its natural state, propane is odorless and
colorless. You may not know all the following safety precautions which can protect both you and your family from an accident.
Read them carefully now, then review them point by point with the members of your household. Someday, when there may not
be a minute to lose, everyone’s safety will depend on knowing exactly what to do. If, after reading the following information, you
feel you still need more information, please contact your gas supplier.
LP Gas Warning Odor
If a gas leak happens, you should be able to smell the gas because of the odorant put in the LP Gas.
That’s your signal to go into immediate action!
•Do not operate electric switches, light matches or use your phone. Do not do anything that could ignite the gas.
•IMMEDIATELY get everyone out of the building, vehicle, trailer or area.
•Close all gas tank or cylinder supply valves.
•LP Gas is heavier than air and may settle in low areas such as basements. When you have reason to suspect a gas
leak, keep out of basements and other low areas. Stay out until firefighters declare them to be safe.
•Use your neighbor’s phone and call a trained LP Gas service technician and the fire department. Even though you may
not continue to smell gas, do not turn on the gas again. Do not re-enter the building, vehicle, trailer or area.
•Have the service technician or fire department air out the area before you return. Properly trained LP Gas service
technician must repair the leak, check and relight the gas furnace for you.
2

Some Points to Remember
•Learn to recognize the odor of LP Gas. Your local LP Gas Dealer can give you a ”Scratch and Sniff” pamphlet. Use
it to find out what the propane odor smells like. If you suspect that your LP Gas has a weak or abnormal odor, call
your LP Gas Dealer.
•If you are not qualified, do not light pilot lights, perform service, or make adjustments to furnaces on the LP Gas
system. If you are qualified, consciously think about the odor of LP Gas prior to and while lighting pilot lights or
performing service or making adjustments.
•Sometimes a basement or a closed–up house has a musty smell that can cover up the LP Gas odor. Do not try to
light pilot lights, perform service or make adjustments in an area where the conditions are such that you may not detect
the odor if there has been a leak of LP Gas.
•Odor fade, due to oxidation by rust or absorption on walls of new cylinders and tanks, is possible. Therefore, people
should be particularly alert and careful when new tanks or cylinders are placed in service. Odor fade can occur in
new tanks or reinstalled old tanks if they are filled and allowed to set too long before refilling. Cylinders and tanks
which have been out of service for a time may develop internal rust which will cause odor fade. If such conditions
are suspected to exist, a periodic sniff test of the gas is advisable. If you have any question about the gas odor,
call your LP Gas dealer. A periodic sniff test of the LP Gas is a good safety measure under any condition.
•If, at any time, you do not smell the LP–Gas odorant, and you should, assume you have a leak. Then take
the same immediate action recommended above for the occasion when you do smell the odorized LP Gas.
•If you experience a complete ”gas out” (the container is under no vapor pressure), turn the tank valve off immediately.
If the container valve is left on, the container may draw in some air through openings such as pilot light orifices.
If this occurs, some new internal rusting could occur. If the valve is left open, then treat the container as a new tank.
Always be sure your container is under vapor pressure by turning it off at the container before it goes completely
empty or having it refilled before it is completely empty.
Technical Data
kW 1.71 mbar 8.7
OUTPUT HEATING CAPACITY kBTU/hr 5,850 NATURAL
GAS in W.C. 3.5
kW 2.17 mbar 24.9
INPUT RATING kBTU/hr 7,400
MAX LP in W.C. 10.0
kW 1.58 mbar 5.5
MINIMUM INPUT RATING kBTU/hr 5,400 NATURAL
GAS in W.C. 2.2
THERMAL EFFICENCY % 79.05 mbar 14.4
mm 478
MANIFOLD PRESSURE
MIN
LP in W.C. 5.8
LENGTH in 18-7/8” m3/h 0.20
mm 577 NATURAL
GAS ft3/h 7.0
HEIGHT in 22-3/4” m3/h 0.08
mm 173
MAX
LP ft3/h 3.0
DEPTH in 6-3/4” m3/h 0.14
kg 17/20 NATURAL
GAS ft3/h 5.1
WEIGHT
(OPERATING/SHIPPED) lbs. 37/44 m3/h 0.06
GAS CONNECTION NPT ½”
MALE
GAS RATE
MIN
LP ft3/h 2.2
mm 105 mbar 17.4
WALL HOLE DIAMETER in 4-1/8” NATURAL
GAS in W.C. 7.0
mm 100 mbar 27.4
AIR INLET DIAMETER in 3-7/8”
MINIMUM INLET
PRESSURE
LP in W.C. 11.0
mm 60
EXHAUST PIPE DIAMETER in 2-3/8”
mm 495
MAX WALL THICKNESS in 19-1/2”
mm 150
MIN WALL THICKNESS in 6
3

Installation
Installation should be done by a QUALIFIED SERVICE TECHNICIAN.
The furnace must be located on an outside wall.
Wall Installation
Minimum clearances from combustible materrials: WARNING: For the installation of this furnace, the
following items must be used as a vent air intake
system:
•Unit to the top surface of carpeting, tile:
2-inches (50 mm)
•Unit to back wall (0” to spacers):
1/4-inch (6.3 mm). External Plate
•Vent to wall enclosure: (Part Number: WFL–STF088)
1-inch (25.4 mm) External Vent Cap
•Unit to sidewalls: (Part Number: WFR–12426530)
2-inches (50 mm) Flanged Air Inlet Tube
•Unit to ceiling: (Part Number: WFR–12476500)
10-inches (254 mm) Air Tube Gasket
(Part Number: WFC–12900128)
See Figure 1 showing clearance for installation of vent cap. Flue Outlet Tube
(Part Number: WFR–12476510)
Leave at least three feet in front of the wall furnace for
servicing and proper operation. The wall furnace must be (All the above items are supplied with the furnace)
installed in such a way that the external casing can be
completely removed for servicing. The diameter of the hole in the wall must exceed at
least 2-inches (50 mm) the diameter of the air inlet tube.
If there is a shelf above the furnace, it must be be
noncombustible. A minimum clearance of 4-inches
(100 mm) is recommended between the furnace and
the noncombustible shelf above it.
Gas equipment in residential garages must be installed so that all burners and burner ignition devices are located not less than
18-inches (460 mm) above the floor. Such equipment shall be located, or protected, so it is not subject to physical damage by a
moving vehicle.
The vent terminal of this direct-vent furnace must be located at least 9-inches (230 mm) from any opening through which flue
gases could enter a building. The bottom of the vent terminal and the air intake must be located at least 12-inches (300mm)
above grade.
DO NOT cover the furnace. WARNING: The nearest point of the vent cap should
be a minimum horizontal distant of six (6) feet (1,830
mm) from any pressure regulator. In case of
regulator malfunction, the six (6) feet (1,830 mm)
distance will reduce the chance of gas entering the
vent cap.
Make sure that the correct gas supply is available. Conversion
To another gas type must be performed by a qualified service
technican. If the type of gas does not correspond to the type to
be used (natural or LP Gas), it must be converted to the correct
type of gas. It is necessary to do the following two operations:
1. Remove and change the pilot orifice with the correct gas type as shown below.
2. Remove and change the burner orifice with the correct gas type as shown below.
3. Remove and change the gas valve with the correct gas type as shown below.
Gas Type Orifice Part Numbers Gas Valve
Natural Burner Orifice: JGLL051; Pilot Orifice: JGLL064 JVLV023
Propane (LP Gas) Burner Orifice: JGLL070; Pilot Orifice: J12160880 JVLV024
4

Figure 1
1 = Fixed/Closed 2 = Openable V = Vent Terminal A = Air Supply
A. Clearance above grade, veranda, porch, deck or
balcony 12-inches (30 cm) minimum. K. Clearance to a mechanical air supply inlet 6 feet (1.8 m)
minimum.
(3) (3)
B. Clearance to window or door that may be opened 12-
inches (30 cm) minimum. L. Clearance
(1) above paved sidewalk or a paved driveway
located on public property 7 feet (2.1 m) minimum.
(3) (3)
C. Clearance to permanently closed window (minimum 12-
inches (30 cm) recommended to prevent condensation
on window.
M. Clearance under veranda, porch, deck or balcony 12-
inches (30 cm) minimum.
(2), (3)
D. Vertical clearance to ventilated soffit located above the
terminal within a horizontal distance of 2 feet (60 cm)
from the centerline of the terminal 18-inches (46 cm)
minimum.
Notes:
(1) A vent shall not terminate directly above a sidewalk
or paved driveway which is located between two
single family dwellings and serves both dwellings.
(2) Only permitted if veranda, porch, deck or balcony is
fully open on a minimum of two sides beneath the
floor.
E. Clearance to unventilated soffit 12-inches (30 cm)
minimum clearance to vinyl soffit 36-inches (90 cm)
minimum.
(3) As specified in CGA B149 installation codes (1991).
F. Clearance to outside corner 12-inches (30 cm)
minimum.
Note: Local codes or regulations may require different
clearances.
G. Clearance to inside corner 18-inches (46 cm) minimum.
H. Not to be installed above a meter/regulator assembly
within 3 feet (90 cm) horizontally from the centerline of
the regulator.
(3)
I. Clearance to service regulator vent outlet 6 feet (1.8 m)
minimum. (3)
J. Clearance to nonmechanical air supply inlet to building
or the combustion air inlet to any other furnace 12-
inches
(
30 cm
)
minimum.
(3)
Outside Location for Vent Terminal
Upon delivery, check to make sure the packaging has not been damaged.
1. Remove the furnace from box/packaging taking care not to damage the paper template. This is to be used to mark the
holes for mounting the furnace.
2. After marking where the appropriate holes will be using the above mentioned template, make a 6-inch (152.4 mm)
diameter hole.
3. Cut the combustion exhaust and fresh air inlet tubes according to the wall thickness:
Air inlet tube length = wall thickness + 11/16 in. (14.4 mm)
F Flue outlet tube length = wall thickness + 3 in. 9/16 (90.5 mm)
4. Drill the mounting holes “A” (5 holes) in the wall. If the wall can receive self–tapping screws, drill 1/8-inch diameter holes.
If not, drill 1/4-inch diameter holes and use the plastic anchors provided.
5

5. Place the insulating sheet on the support bracket and attach the bracket with insulation to the wall by tightening the five
screws with washer. (Figure 3) Be sure the bracket is horizontal.
6. Remove the casing from the furnace body, unscrewing the two mounting screws. (Figure 3)
7. Mount the largest tube (diameter 4-inches (101.6 mm) and the gasket on the unit frame with the screws provided.
Insert the smallest tube (diameter 2½-inches, 63.5 mm) in the combustion chamber. (Figure 4)
Figure 2
Ø152.4 mm
Ø63.5
A
+ 17.4 mm A + 90.5 mm
Ø101.6
Figure 3
Figure 4
Figure 5
6

8. Position the furnace on the wall inserting the inlet/outlet flue in the hole previously drilled. Make sure that the edges of the
support bracket perfectly match the existing holes in the back on the unit (Figure 5)
9. Attach the furnace to the support bracket with the two screws provided. During this operation make all necessary
adjustments to have a correct installation of the unit (Figures 5 and 6)
10. Reinstall the external casing by tightening the relevant screws (Figure 3).
11. On the external side of the wall, install the protection plate in such a way that the center of the hole in the plate matches
the center of the hole in the wall. First place the plate in the right position and mark the holes on the wall. Then, remove
the plate and drill the holes in the wall. If the wall can receive self–tapping screws, drill 1/8-inch diameter holes. If not, drill
1/4-inch diameter holes and use the plastic anchors provided. Reposition the plate and fix it onto the wall with the four
screws provided. (Figure 7 - Left)
12. Mount the vent cap on the flue pipe and fix it onto the external plate with the three self–tapping screws provided. (Figure 7
- Right)
13. Connect the gas supply line. A gas tap just before each furnace must be installed.
14. Turn on gas supply and check for gas leaks with soapy water or other suitable means on all gas connections.
Figure 6
Figure 7
Gas Supply
Check all local codes for requirements, especially for the size and type of gas supply line required. On natural gas lines less than
15” (380 mm) long, use 1/2” tube; on longer runs, use 3/4” iron tube or equal. On LP gas lines please consult LP Gas supplier.
Installing a New Main Gas Cock
Each furnace should have its own manual gas cock. A manual main gas cock should be located in the vicinity of the unit. Where
none exists, or where its size or location is not adequate, contact your local authorized installer for installation or relocation.
Compounds used on threaded joints of gas piping shall be resistant to the action of LP Gas. The gas lines must be checked for
leaks by the installer. This should be done with a soap solution watching for bubbles on all exposed connections, and if
unexposed, a pressure test should be made.
Never use an exposed flame to check for leaks. Furnace must be disconnected from piping at inlet of control valve and
pipe capped or plugged for pressure test. Never pressure test with furnace connected; control valve will sustain
damage!
A gas valve and ground joint union should be installed in the gas line upstream of the gas control to aid in servicing. It is required
by the National Fuel Gas Code that a drip line be installed near the gas inlet. This should consist of a vertical length of pipe tee
connected into the gas line that is capped on the bottom in which condensation and foreign particles may collect.
The use of the following gas connectors is recommended:
– ANSI Z21.24 Appliance Connectors of Corrugated Metal Tubing and Fittings., CGA 6.10.
– ANSI Z21.45 Assembled Flexible Appliance Connectors of Other Than All–Metal Construction.
The above connectors may be used if accepted by the authorities having jurisdiction.
Pressure Testing of the Gas Supply System
1. To check the inlet pressure to the gas valve, a plugged tapping, accessible for test gauge connection, is provided on the
gas valve. (Figure 8 - A).
2. The furnace and its individual shutoff valve must be disconnected from the gas supply piping system during any pressure
testing of that system at test pressures in excess of 1/2 psig (3.5 kPa).
7

3. The furnace must be isolated from the gas supply piping system by closing its individual manual shutoff valve during any
pressure testing of the gas supply piping system at test pressures equal to or less than 1/2 psig (3.5 kPa).
Attention: If one of the above procedures results in pressures in excess of 1/2 psig (14” w.c.; 3.5 kPa) on the furnace gas valve,
it will result in a hazardous condition.
High Altitudes (US Only)
For altitudes/elevations above 2,000 feet (610 m), ratings should be reduced at the rate of 4-percent for each 1,000 feet (305 m)
above sea level by reducing the manifold pressure at 8% rate on the gas supply. Maximum altitude allowed for installation is
5500 feet (1680 m).
High Altitudes (Canada Only)
The furnace is tested according to CGA 2.17 M91 for installation between 0 and 4500 ft (0 and 1370 m) altitude. For
altitudes/elevations above 2,000 feet (610 m), ratings should be reduced at the rate of 4-percent for each 1000 feet (305 m)
above sea level by reducing the manifold pressure at 8% rate on the gas supply. Maximum altitude allowed for installation is
5500 feet (1680 m).
First Firing the Furnace
Start the furnace following the instructions given in the “Operating Instructions”. The first lighting can be difficult because of the
air trapped in the gas lines. During initial firing of the furnace, residual manufacturing grease will bake out and smoke will occur
which is not a health danger. To prevent nuisance and operation of fire alarms, ventilate the room for the first two hours of
operation.
Checking the Gas Inlet Pressure
The gas inlet pressure can be measured by connecting a test gauge to the connection provided on the gas valve. (Figure 8 - A)
Once installation is complete, the gas inlet pressure must be checked. The minimum gas inlet pressure must be as shown in
“Technical Data”. After checking the gas inlet pressure, disconnect the test gauge and firmly tighten the screw of the gauge
connection, then check for gas leaks.
Checking the Gas Manifold Pressure
The gas manifold pressure can be measured by connecting a test gauge to the connection provided on the gas valve. (Figure 8 -
B). The furnace comes set from the factory at the correct manifold gas pressure. After the installation is completed, the gas
manifold pressure must be checked both in Hi and Lo input. Turn the control knob to switch the unit from Hi to Lo input. The
position of the knob in which this occurs depends on the actual room temperature. The gas manifold pressure must be as
shown in “Technical Data”. Differences of plus or minus 0.1 in. w.c. are accepted. If the Hi or Lo gas manifold pressures are
different from the values given in the “Technical Data” or are more than 0.1 in. w.c., shut off the furnace and contact a qualified
service technician.
For instructions about adjustment of the manifold Hi and Lo pressures, see the "Servicing” section. After checking the gas
manifold pressure, disconnect the test gauge and tighten firmly the screw of the gauge connection, then check for gas leaks
from it.
Figure 8
8

Operating Instructions
Before operating the furnace, read carefully all warnings and safety information in this manual.
FOR YOUR SAFETY READ BEFORE OPERATING
A. This appliance has a pilot which must be
lighted by means of the piezo igniter
installed on the unit. Do not try to light the
pilot by hand.
B. BEFORE LIGHTING smell all 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
- Do not touch any electric switch; Do
not use any phone in your building
- Immediately call your gas supplier
from a neighbour’s phone.
Follow the gas supplier’s instructions.
- If you cannot reach your gas supplier, call the fire
department.
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 h nd, don’t try to repair it, call a qualified service
technician. Force or attempted repair may result in a fire or
explosion.
D. Do n t 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 ny gas control which has been under water.
a
o
a
WARNING: If you do not follow these instructions exactly, a fire or explosion
ma
y
result causin
g
p
ro
p
ert
y
dama
g
e,
p
ersonal in
j
ur
y
or loss of life.
OPERATING INS TRUCTIONS
1. STOP! Read the safety information above on this labe .
2. Turn gas control knob clockwise to OFF. Do not force.
3. Wait (5) minutes to clear out any gas. If you then sme gas, STOP! Follow “B” in the
safety information above on this label. If you don’t sm ll gas, go to the next step.
4. Turn gas knob counterclockwise to PILOT.
5. Look inside the flame view which is located on the ex rnal casing.
6. Push in control knob all the way and hold in. Immedia ely press the piezo igniter to
end of the stroke, then release it. Continue pressing a d releasing the piezo igniter
with the control knob pressed down, until the pilot flame appears in the flame view.
Once the pilot flame is lit, hold the control knob in fo bout one (1) minute.
7. Release knob and it will pop back up. Pilot should remain lit. If it goes out, repeat
steps 2. trough 6. .
- If knob does not pop up when released, stop and tu the gas tap installed on the
gas supply line to the CLOSED position. Immediately call your service agency or gas
supplier.
- 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.
8. Turn the control knob counterclockwise to the desired setting between HI and
LO. The main burner flame will appear.
l
ll
e
te
t
n
r a
rn
TO TURN OFF GAS O APPLIANCE T
1. Turn the control knob clockwise to OFF positi n. Do not try to switch from HI to OFF directly. Do not
force.
2. Turn the gas tap installed on the gas supply to the CL SED position.
o
O
9

Servicing
All servicing activities must be carried out by a qualified service technicial or a service agency. The home owner may not
service the furnace. The home owner must read this section to be informed of the periodic maintenance and checks the
required. All servicing (except on vent system) must be carried out with the external casing removed. After any servicing, the
external casing must be reinstalled properly.
Checking and Adjusting the Gas Manifold Pressure
The furnace comes set from the factory at the correct HI and LO gas manifold pressures as shown in “Technical Data”. It is
recommended to check the pressures periodically (minimum once a year). If adjustment is required, this can be done by
adjusting screws C and D. (Figure 8) A test gauge must be connected as explained in “Checking the Gas Manifold Pressure”.
Proceed as follows:
1. Place the unit on and in the HI mode (knob in HI position).
2. Adjust the HI pressure by turning the screw C (pressure regulator) to the value given in “Technical Data”. Turn clockwise
to increase the pressure, turn counterclockwise to decrease it.
3. Turn the control knob clockwise until the gas control switches to LO mode. The position in which this occurs depends on
the actual room temperature.
4. Loosen screw D until the correct value for the LO pressure is achieved. Turn clockwise to decrease the pressure, turn
counterclockwise to increase it.
5. Switch the unit from LO to HI mode to check that both the HI and LO pressures are correct. A tolerance of plus or minus
0.1-inches w.c. on the pressure value is acceptable. Readjust if needed.
6. Disconnect the test gauge and tighten firmly the screw of the gauge connection, then check for gas leaks from it.
The HI and LO pressures must be adjusted in the way explained above. Never try to adjust them independently from each other.
Checking, Removing and Reassembling of the Vent Air Intake System
It is essential that the vent air intake system is examined periodically (minimum once a year) to verify it is clean from dust and
deposits of solid materials such as leaves or nests. The vent air intake system is checked from outside. Proceed as follows:
1. Remove the vent cap by removing the three outer screws. (Figure 7)
2. Remove the inner flue pipe. Do not use tools; the pipe can be extracted by hand.
3. Remove dust and desposits from the vent cap and flue pipes. Deposits in the air pipe must be taken outside. Do not
push them inside the furnace. The outer air pipe may not be removed from outside.
4. Reinstall the flue pipe from outside. Do not use glue or sealants.
5. Reinstall the vent cap on the flue pipe. Do not use glue or sealants. Tighten the three outer screws.
Lubrication of Moving Parts
This furnace does not require lubrication. Do not try to lubricate any part of the furnace such as motors bearings, keys, knobs,
screws, etc.
Flame Visual Check
Correct and proper operation of the burner may be checked by examinng the burner flame. The flame may be examined
through the front flame viewer. The flame must be stable and have blue color. Some small yellow tips are acceptable with
propane gas. If the flame is yellow or has excessive turbulence, check the gas manifold pressure and the vent air intake system.
If all these are acceptable, call a qualified service technician for a complete check of the furnace. Call also your gas supplier to
check the composition of the gas in use.
10

Replacement Parts
Gas Valve
Part Number: JVLV023
(Natural Gas)
Part Number: JVLV024
(LPG)
Pilot
Sparking
Candle and
Nozzle
Part Number: J12306065
(Sparking Candle)
Part Number: JGLL064
(Nozzle – Natural Gas)
Part Number: J12160880
(Nozzle - LPG)
Piezo
Electric
Button Part Number: JPZO000
Thermocouple Part Number: JTRM000D
Burner Part Number:
J90021028
Pilot Part Number:
J12100450
Pilot
Gasket Part Number: 12900043
Burner
Nozzle
Part Number: JGLL051
(Natural Gas)
Part Number: JGLL070
(LPG)
11