www.desatech.com
122280-01D
36
tROuBLEShOOtInG
Note: Before troubleshooting the system, make sure the gas shutoff valve is ON. 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
POSSIBLE CAUSE
1. No gas supply or shutoff
valve is OFF
2. Air in gas line
3. Construction debris clog
-
ging 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
1. Loose wiring on ignitor
wire to ignition module
and/or poor ground to igni-
tion module
2. Pilot flame too low to
sense
1. Wall switch wires defective
or too long
2. Thermopile not generating
sufficient voltage
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 repeated
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 (re
-
fer to
Replacement Parts
,
page 34)
7. Check that main power is
on and that all wire connec-
tions are made correctly to
ignition model (see
Wiring
Diagram
, page 35). Check
for 24 VAC at the secondary
side of transformer. If 24
VAC is present and module
does not operate, have
module replaced otherwise
have transformer replaced
1. Check wiring connection.
Refer to wiring diagram,
page 35, and/or check
ground wire to ignition mod-
ule
2. Clean and adjust pilot burn
-
er and check gas supply
and inlet pressure to unit
Note: Have a qualified tech-
nician replace pilot assem-
bly if broken or corroded
1. Check electrical connec-
tions
2. Recheck problems 1 and 2
