Desa CBN20T EN - Manual (Page 20)

www.desatech.com 107882-01K 20
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
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
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
1. Not enough air
2. Gas regulator defective
3. Clogged or dirty burner
1. Residues from manufacturing
processes
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
combustion
Yellow flame during burner
combustion
Slight smoke or odor during initial
operation
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. 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
1. Check burner for dirt and de-
bris. If found, clean burner (see
Cleaning and Maintenance,
page 17)
2. Replace gas regulator
3. Clean burner (see Cleaning
and Maintenance, page 17)
1. Problem will stop after a few
hours of operation
TROUBLESHOOTING
Continued