Vanguard Heating VN1800ITB - Manual (Page 15)

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OWNER’S MANUAL
TROUBLESHOOTING
OBSERVED PROBLEM
When ignitor button is pressed in, there is no
spark at ODS/pilot
When ignitor button is pressed in, there is a
spark at ODS/pilot but no ignition
ODS/pilot lights but flame goes out when
control knob is released
POSSIBLE CAUSE
1. Ignitor electrode positioned wrong
2. Ignitor electrode broken
3. Ignitor electrode not connected to igni-
tor cable
4. Ignitor cable pinched or wet
5. Broken ignitor cable
6. Bad piezo ignitor
7. Piezo ignitor nut is loose
1. Gas supply turned off or equipment
shutoff valve closed
2. Control knob not fully pressed in while
pressing ignitor button (non-thermostat
models only)
Thermostat control knob not fully
pressed in while pressing ignitor button
(thermostat models only)
3. Air in gas lines when installed
4. ODS/pilot is clogged
5. Gas regulator setting is not correct
6. Thermostat control knob not in pilot
position
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 con-
trol valve
5. Pilot flame not touching thermocouple,
which allows thermocouple to cool,
causing pilot flame to go out. This prob-
lem 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 trig-
gered (thermostat models only)
REMEDY
1. Replace ignitor
2. Replace ignitor
3. Reconnect ignitor cable
4. Free ignitor cable if pinched by any
metal or tubing. Keep ignitor cable dry
5. Replace ignitor cable
6. Replace control valve (piezo is part of
control valve)
7. Tighten nut holding piezo ignitor. Nut
is located inside heater cabinet at top
1. Turn on gas supply or open equipment
shutoff valve
2. Fully press in control knob while press-
ing ignitor button (non-thermostat mod-
els only)
Fully press in thermostat control knob
while pressing ignitor button (thermo-
stat models only)
3. Continue holding down control knob. Re-
peat igniting operation until air is removed
4. Clean ODS/pilot (see Cleaning and
Maintenance, page 14) or replace ODS/
pilot assembly
5. Replace gas regulator
6. Turn thermostat control knob to pilot
position
1. Press in control knob fully
2. After ODS/pilot lights, keep control
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 gas company
B) Clean ODS/pilot (see Cleaning and
Maintenance, page 14) or replace ODS/
pilot assembly
6. Replace thermocouple
7. Replace control valve
8. Wait one minute for safety interlock sys-
tem to reset. Repeat ignition operation
WARNING: Turn off and un-
plug heater and let cool before
servicing. Only a qualified ser-
vice person should service and
repair heater.
CAUTION: Never use a wire,
needle, or similar object to clean
ODS/pilot. This can damage ODS/
pilot unit.
Continued
Note: For additional help, visit DESA
International’s technical service web site
at
www.desatech.com .
Note: All troubleshooting items are listed in
order of operation.
www.desatech.com