Vanguard VMH26TNC - Manual (Page 25)

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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 al-
lows thermocouple 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 too low
1. Manifold pressure too low
2. Burner orifice is clogged
1. Burner orifice is clogged or
damaged
2. Burner damaged
3. Low inlet gas pressure
4. Gas regulator defective
1. Not enough air
2. Gas regulator defective
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
interlock system to reset.
Repeat ignition operation
4. Fully open equipment shut-
off valve
5. Hand tighten until snug,
then tighten 1/4 turn more
6. A) Contact local propane/LP
or natural gas company
B) Clean ODS/pilot (see
Cleaning and Maintenance,
page 23) or replace ODS/
pilot assembly
7. Replace pilot assembly
8. Replace control valve
1. Clean burner (see Cleaning
and Maintenance, page 23)
or replace burner orifice
2. Contact local propane/LP
or natural gas company
1. Contact local propane/LP
or natural gas company
2. Clean burner (see Cleaning
and Maintenance, page 23)
or replace burner orifice
1. Clean burner (see Cleaning
and Maintenance, page 23)
or replace burner orifice
2. Replace burner pressure
3. Contact local propane/LP
or natural gas company
4. Replace gas regulator
1. Check burner for dirt and
debris. If found, clean
burner (see Cleaning and
Maintenance, page 23)
2. Replace gas regulator
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
TRoUBlesHooTIng
Continued