www.desatech.com
19
119346-01B
TROUbLESHOOTING
Continued
POSSIBLE CAUSE
1. Control knob not fully
pressed in
2. Control knob not pressed in
long enough
3. Equipment shutoff valve not
fully open
4. Thermocouple connection
loose at control valve
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 damaged
7. Control valve damaged
8. Safety interlock system has
been triggered (thermostat
models only)
1. B u r n e r o r i f i c e ( s ) i s
clogged
2. Inlet gas pressure is too
low
1. Manifold pressure is too
low
2. B u r n e r o r i f i c e ( s ) i s
clogged
1. Burner orifice(s) is clogged
or damaged
2. Burner damaged
3. Gas regulator defective
1. Plaque damaged
2. Inlet gas pressure is too
low
3. Control knob set between
locked positions
1. Residues from manufactur
-
ing processes
1. Metal expanding while
heating or contracting while
cooling
REMEDY
1. Press in control knob fully
2. After ODS/pilot lights, keep
control knob pressed in 30
seconds
3. Fully open equipment shut
-
off valve
4. Hand tighten until snug,
then tighten 1/4 turn more
5. A) Contact local natural or
propane/LP gas company
B) Clean ODS/pilot (see
Cleaning and Maintenance
,
page 16) or replace ODS/
pilot assembly
6. Replace pilot assembly
7. Replace control valve
8. Wait one minute for safety
interlock system to reset.
Repeat ignition operation
1. Clean burner orifice(s) (see
Cleaning and Maintenance
,
page 16) or replace burner
orifice(s)
2. Contact local natural or
propane/LP gas company
1. Contact local natural or
propane/LP gas company
2. Clean burner orifice(s) (see
Cleaning and Maintenance
,
page 16) or replace burner
orifice(s)
1. Clean burner orifice(s) (see
Cleaning and Maintenance
,
page 16) or replace burner
orifice(s)
2. Replace burner
3. Replace gas regulator
1. Replace burner
2. Contact local natural or
propane/LP gas company
3. Turn control knob until it
locks at desired setting
1. Problem will stop after a few
hours of operation
1. This is normal with most heat
-
ers. If noise is excessive, con
-
tact qualified service person
OBSERvED PROBLEM
ODS/pilot lights but flame
goes out when control knob
is released
Burner(s) does not light after
ODS/pilot is lit
Delayed ignition of burner(s)
Burner backfiring during
combustion
Burner plaque(s) does not
glow
Slight smoke or odor during
initial operation
Heater produces a clicking/
ticking noise just after burner
is lit or shut off
