Desa VSL18NT - Manual (Page 19)

www.desatech.com 116292-01D 19
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
REMEDY
1. Press in control knob fully
2. After ODS/pilot lights, keep
control 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. Hand tighten until snug, then
tighten 1/4 turn more
6. A) Contact local natural or
propane/LP gas company
B) Clean ODS/pilot (see
Cleaning and Maintenance ,
page 17) or replace ODS/pilot
assembly
7. Replace pilot assembly
8. Replace control valve
1. Clean burner (see Cleaning
and Maintenance, page 17)
or replace burner orifice
2. Contact local natural or pro-
pane/LP gas company
1. Contact local natural or pro-
pane/LP gas company
2. Clean burner (see Cleaning
and Maintenance, page 17)
or replace burner orifice
1. Clean burner (see Cleaning
and Maintenance, page 17)
or replace burner orifice
2. Replace burner
3. Replace gas regulator
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. Thermocouple connection
loose at control valve
6. Pilot flame not touching ther-
mocouple, which allows ther-
mocouple to cool, causing
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
7. Thermocouple damaged
8. Control valve damaged
1. Burner orifice is clogged
2. Inlet gas pressure is too low
1. Manifold pressure is too low
2. Burner orifice is clogged
1. Burner orifice is clogged or
damaged
2. Burner damaged
3. Gas regulator defective
TROUBLESHOOTING
Continued