Desa VMH10TPC - Manual (Page 32)

www.desatech.com 112462-01F 32
TROUBLESHOOTING
Continued
OBSERVED PROBLEM
ODS/pilot lights but flame goes out
when control knob is released
Burner does not light after ODS/
pilot is lit
Delayed ignition of burner
Burner backfiring during com-
bustion
POSSIBLE CAUSE
1. Control knob not fully
pressed in
2. Control knob not pressed in
long enough
3. Safety interlock system has
been triggered
4. Equipment shutoff valve not
fully open
5. Pilot flame not touching
thermocouple, which allows
thermocouple to cool, caus-
ing pilot flame to go out. This
problem could be caused by
one or both of the following:
A) Low gas pressure
B) Dirty or partially clogged
ODS/pilot
6. Thermocouple connection
loose at control valve
7. Thermocouple damaged
8. Control valve damaged
1. Inlet gas pressure is too low
2. Burner orifice is clogged
3. Thermopile leads discon-
nected or improperly con-
nected (Remote-Ready Mod-
els Only)
4. Burners will not come on in
remote position (Remote-
Ready Models Only)
1. Manifold pressure is too low
2. Burner orifice is clogged
1. Burner orifice is clogged or
damaged
2. Damaged burner
3. Gas regulator defective
4. Inlet gas pressure is too low
REMEDY
1. Press in control knob fully
2. After ODS/pilot lights, keep con-
trol knob pressed in 30 seconds
3. Wait one minute for safety in-
terlock system to reset. Repeat
ignition operation
4. Fully open equipment shutoff
valve
5. A) Contact local natural or
propane/LP gas company
B) Clean ODS/pilot (see
Cleaning and Maintenance,
page 30) or replace ODS/pilot
assembly
6. Hand tighten until snug, then
tighten 1/4 turn more
7. Replace pilot assembly
8. Replace control valve
1. Contact local natural or pro-
pane/LP gas company
2. Clean burner (see Cleaning
and Maintenance, page 30) or
replace burner orifice
3. Reconnect leads (see Wiring
Diagram, page 35)
4. Replace battery in hand-held
remote and receiver
1. Contact local natural or pro-
pane/LP gas company
2. Clean burner (see Cleaning
and Maintenance, page 30) or
replace burner orifice
1. Clean burner (see Cleaning
and Maintenance, page 30) or
replace burner orifice
2. Replace damaged burner
3. Replace gas regulator
4. Contact local natural or pro-
pane/LP gas company