111907-01D
For more information, visit www.desatech.com
For more information, visit www.desatech.com
28
TROUBLESHOOTING
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
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 knob is not opening
7. No power to unit or the ignition module
or power transformer is bad
8. Vent damper not fully open
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 pi-
lot line
6. Replace control valve (Refer to Replace-
ment Parts, page 34)
7. Check that main power is on and that all
wire connections are made correctly to
the ignition model (see Wiring Diagram,
page 24). Check for 24 VAC at the sec-
ondary side of the transformer. If 24
VAC is present, and the module does not
oporate, have the module replaced oth-
erwise have the transformer replaced.
8. Open vent damper until fully locked in
OPEN position
1. Check wiring connection. Refer to wir-
ing diagram (see Wiring Diagram, page
24) and/or check ground wire to igni-
tion 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
Note:
For additional help, visit DESA’s
technical service web site at
www.desatech.com.
Note:
Before troubleshooting the system, make
sure the gas shutoff valve is ON.
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.
