Desa (V)VC42NE - Manual (Page 26)

26
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TROUBLESHOOTING
TROUBLESHOOTING
WARNING: Turn off heater and let cool before
servicing. Only a qualified service person should
service and repair heater.
Note: All troubleshooting items are listed in order of operation.
OBSERVED PROBLEM
Ignitor will not spark or pilot will not light
Pilot will not stay lit
No gas to burner, although wall switch and
valve are set to the ON position
Frequent pilot outage
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 is not opening
7. No power to unit or the ignition module
or power transformer is bad
1. Loose wiring on ignitor wire to ignition
module and/or poor ground to ignition
module
2. Pilot flame too low to sense
1. Wall switch wires defective or too
long
1. Pilot flame may be too low, causing
safety pilot to “drop out”
2. Improper venting or excessive blockage
REMEDY
1. Check to see if you have gas supply and
that equipment shutoff valve is opened
2. Repeat lighting procedure several times
to purge all air out of lines. If after re-
peated attempts appliance does not light,
call for qualified service and repair.
3. Remove debris and dirt, inspect 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 Replace-
ment Parts, page 28)
7. Check that main power is on and that all
wire connections are made correctly to
the ignition model (see Wiring Diagram,
page 23). Check for 24 VAC at the
secondary side of the transformer. If 24
VAC is present and the module does not
operate, have the module replaced oth-
erwise have the transformer replaced
1. Check wiring connection. Refer to wir-
ing diagram (see Wiring Diagram, page
23) and/or check ground wire to ignition
module
2. Clean and adjust pilot burner and check
gas supply and inlet pressure to unit
Note: Have a qualified technician replace
pilot assembly if broken or corroded
1. Check electrical connections
1. Clean and adjust pilot flame for maximum
flame impingement on thermopile
2. Have the vent system inspected, includ-
ing the termination cap. Remove any
restriction or obstruction
CAUTION: Never use a wire, needle or similar
object to clean pilot. This can damage pilot unit.