17
NV360/580 Series
20003565
Troubleshooting
SIT NOVA 820 MILLIVOLT VALVE
NOTE: Before troubleshooting the gas control system, be sure external gas shut off is in the "ON" position.
WARNING: BEFORE DOING ANY GAS CONTROL SERVICE WORK, REMOVE GLASS FRONT.
SYMPTOM
1. Spark ignitor will not light.
2. Pilot will not stay lit after
carefully following lighting
instructions.
3. Pilot burning, no gas to
main burner.
4. Frequent pilot outage
problem.
POSSIBLE CAUSES
A. Defective or misaligned elec-
trode at pilot.
B. Defective ignitor (push button)
A. Defective pilot generator (ther-
mocouple), remote wall switch.
B. Defective automatic valve.
A. Wall switch or wires defective.
B. Thermopile may not be gener-
ating sufficient millivoltage.
C. Plugged burner orifice.
D. Defective automatic valve op-
erator.
A. Pilot flame may be too low or
blowing (high) causing the pilot
safety to drop out.
B. Possible blockage of the vent
terminal.
CORRECTIVE ACTION
Using a match, light pilot. If pilot lights, turn off pilot and
push the red button again. If pilot will not light - check gap
at electrode and pilot -should be 1/8" to have a strong
spark.
Push piezo ignitor button. Check for spark at electrode
and pilot. If no spark to pilot, and electrode wire is prop-
erly connected, replace ignitor.
Check pilot flame. Must impinge on thermocouple/ther-
mopile.
NOTE:
This pilot burner assembly utilizes both - a
thermocouple and a thermopile. The thermocouple oper-
ates the main valve operation ("ON" and "OFF"). Clean
and/or adjust maximum flame impingement on thermopile
and thermocouple.
Turn valve knob to "PILOT". Maintain flow to pilot; millivolt
meter should read greater than 10 mV. If the reading
is okay and the pilot does not stay on, replace the gas
valve.
NOTE:
An interrupter block (not supplied) must be
used to conduct this test.
Check wall switch and wires for proper connections.
Jumper wire across terminals at wall switch, if burner
comes on, replace defective wall switch. If okay, jumper
wires across wall switch wires at valve. If burner comes
on, wires are faulty or connections are bad.
1. Be sure wire connections from thermopile at gas valve
terminals are tight and thermopile is fully inserted into
pilot bracket.
2. One of the wall switch wires may be grounded.
Remove wall switch wires form valve terminals if pilot
now stays lit, trace wall switch wiring for ground. May
be grounded to fireplace or gas supply.
3. Check thermopile with millivolt meter. Take reading at
thermopile terminals of gas valve. Should read 250-
300 millivolts (minimum 150) while holding valve knob
depressed in pilot position and wall switch "OFF".
Replace faulty thermopile if reading is below specified
minimum.
Check burner orifices for debris and remove.
Turn valve knob to "ON", place wall switch to "ON". Milli-
volt meter should read greater than 100 mV. If the reading
is okay and the burner does not come on, replace the gas
valve.
Clean and/or adjust pilot flame for maximum flame im-
pingement on thermopile and thermocouple.
Check the vent terminal for blockage (recycling the flue
gases).
