935CA: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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2. Remove control door.
3. Disconnect wires or connectors to burner thermal switch, gas valve,
igniter, and flame sensor.
4. Using backup wrench, disconnect gas supply pipe from furnace gas
control valve.
5. Remove screws attaching burner assembly to cell panel.
NOTE:
Burner, manifold, gas valve, and orifice should be removed as
one assembly.
6. Carefully remove burner insulation assembly, Insulation MUST be
replaced before reassembly.
7. Clean heat exchanger openings with a vacuum and a soft brush, see
Fig. 74
.
A190291
Fig. 74 – Cleaning Heat Exchanger Cell
NOTE:
After cleaning, inspect the heat exchangers to ensure they are
free of all foreign objects that may restrict flow of combustion products.
8. Reverse items 6 through 1. for reassembly. Torque burner screws to
45 inch-pound to ensure a tight burner seal.
9. Refer to furnace wiring diagram and reconnect wires to burner
thermal switch, gas valve, igniter, and flame sensor.
10. Turn on gas and electrical supplies to furnace.
11. Check furnace operation through two complete heat operating
cycles.
12. Check for gas leaks.
13. Replace main furnace door.
Secondary Heat Exchangers
The condensing side (inside) of the secondary heat exchanger CANNOT
be serviced or inspected without complete removal of the heat exchanger
assembly. Detailed information on heat exchanger removal can be
obtained from your Distributor.
WINTERIZATION
Since the furnace uses a condensing heat exchanger, some water will
accumulate in the unit as a result of the heat transfer process. Therefore,
once it has been operated, it cannot be turned off and left off for an
extended period of time when temperatures will reach 32
_
F (0
_
C) or
lower unless winterized. Follow these procedures to winterize your
furnace:
1. Obtain propylene glycol (RV/swimming pool antifreeze or
equivalent).
2. Turn off gas and electrical supplies to your furnace.
3. Remove furnace control door.
WARNING
!
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury or death,
or property damage.
Before installing, modifying, or servicing system, main electrical
disconnect switch must be in the OFF position and install a lockout tag.
There may be more than one disconnect switch. Lock out and tag
switch with a suitable warning label. Verify proper operation after
servicing. Always reinstall access doors after completing service and
maintenance.
WARNING
!
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Turn off the gas and electrical supplies to the furnace and install lockout
tag before performing any maintenance or service. Follow the operating
instructions on the label attached to the furnace.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Never purge a gas line into a combustion chamber. Never test for gas
leaks with an open flame. Use a commercially available soap solution
made specifically for the detection of leaks to check all connections. A
fire or explosion may result causing property damage, personal injury
or loss of life.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Never purge a gas line into a combustion chamber. Never test for gas
leaks with an open flame. Use a commercially available soap solution
made specifically for the detection of leaks to check all connections. A
fire or explosion may result causing property damage, personal injury
or loss of life.
CAUTION
!
UNIT AND PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in unit component or property
damage.
If the furnace is installed in an unconditioned space where the ambient
temperatures may be 32
_
F (0
_
C) or lower, freeze protection measures
must be taken to prevent minor property or product damage.
CAUTION
!
UNIT COMPONENT DAMAGE HAZARD
Failure to follow this caution may result in damage to the furnace and
other property damage.
Do not use ethylene glycol (automotive antifreeze coolant or
equivalent). Failure of plastic components may occur.
