Desa VTN25R ES - Manual (Page 18)

www.desatech.com 113261-01A 18
TROUBLESHOOTING
Continued
POSSIBLE CAUSE
1. Pilot knob not fully pressed in
2. Pilot 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 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
6. Thermocouple damaged
7. Valve damaged
1. Burner orifice(s) is clogged
2. Inlet gas pressure is too low
1. Manifold pressure is too low
2. Burner orifice(s) is 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
1. Residues from manufacturing
processes
1. Metal expanding while heating
or contracting while cooling
REMEDY
1. Press in pilot knob fully
2. After ODS/pilot lights, keep pi-
lot knob pressed in 30 seconds
3. Fully open equipment shutoff
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 valve
1. Clean burner orifice(s) (see
Cleaning and Maintenance, page
16) or replace burner orifice(s)
2. Contact local natural or pro-
pane/LP gas company
1. Contact local natural or pro-
pane/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 pro-
pane/LP gas company
1. Problem will stop after a few
hours of operation
1. This is common with most heat-
ers. If noise is excessive, contact
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 com-
bustion
Burner plaque(s) does not glow
Slight smoke or odor during
initial operation
Heater produces a clicking/tick-
ing noise just after burner is lit
or shut off