Desa (V)T36ENA - Manual (Page 31)

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TROUbLEShOOTING
WARNING: Turn off heater and let cool before servicing. Only a
qualified service person should service and repair heater.
CAUTION: Never use a wire, needle, or similar object to clean
pilot. This can damage pilot unit.
The two most common causes of a malfunctioning gas appliance are:
1. Loose wiring connections
2. Construction debris clogging the pilot and/or gas control valve filter
Note: Before troubleshooting the system, make sure the gas shutoff valve is ON.
OBSERVED PROBLEM
Ignitor will not spark or pilot will
not light
POSSIBLE CAUSE
1. No gas supply, or shutoff valve
is OFF
2. Air in gas line
3. Construction debris clogging
pilot orifice
4. Low gas pressure
5. Kinked pilot line
6. Control valve knob is not
opening
7. No power to unit or the igni-
tion module or power trans-
former is bad
8. Vent damper not fully open
REMEDY
1. Check to see if you have gas
supply and that equipment
shutoff valve is opened
2. Repeat lighting procedure sev-
eral times to purge all air out of
lines. If after repeated attempts
appliance does not light, call for
qualified service and repair.
3. Remove debris and dirt, in-
spect and clean any other
possible obstructions
4. Contact your gas supplier to
check pressure
5. Have a qualified technician
replace pilot line
6. Replace control valve (Refer to
Replacement Parts, page 38)
7. Check that main power is on
and that all wire connections are
made correctly to the ignition
model (see Wiring Diagram,
page 27). Check for 24 VAC at
the secondary side of the trans-
former. If 24 VAC is present,
and module does not operate,
have module replaced otherwise
have transformer replaced.
8. Open vent damper until fully
locked in OPEN position
CLEANING AND MAINTENANCE
Continued
vENTING SYSTEM
Conduct annual inspection of the venting system
following these guidelines:
1. Check areas of venting system that are ex-
posed to the weather for corrosion (rust spots
or streaks and, in extreme cases, holes). Have
these items replaced immediately by a quali-
fied service person.
2. Remove the vent cap and shine a flashlight
into the vent. Remove any foreign material.
3. Check for evidence of excessive condensation.
Continuous condensation can cause corrosion
of caps, pipes, and fittings and can be caused
by having excessive lateral runs, too many
elbows, or exterior portions of the system
being exposed to cold weather.
4. Inspect joints to verify that no pipe section or
fitting has been disturbed and loosened. Check
mechanical supports such as wall straps for
rigidity.