Troubleshooting Gas Control (Sit 820 Millivolt Gas Valve) - Vermont Castings BHDT36 Installation Instructions & Homeowner's Manual

TROUBLE SHOOTING THE GAS CONTROL SYSTEM
GLASS DOOR TO BE REMOVED BEFORE SERVICE WORK
START
GAS SUPPLY ON
LIGHT PILOT WITH
PIEZO IGNITION
YES
PILOT STAYS ON
YES
MAIN BURNER ON
SIT 820 NOVA MILLIVOLT VALVE
CHECK
NO
NO
• ELECTRODE GAP MIN. 1/8"
• ELECTRODE CRACKED
• ELECTRODE CABLE ATTACHED
• PIEZO IGNITOR GENERATES
SPARK
• ELECTRODE CABLE NOT
GROUNDED
NO
• FLAME ENGULFING
THERMOCOUPLE BY 3/8"
• THERMOCOUPLE ATTACHED
TO VALVE
• MNIMUM MILLIVOLT:
• VENT SAFETY SWITCH TIGHT
AND NO SHORTS
(FOR UNITS EQUIPPED WITH
VENT SAFETY SWITCH)
• REMOTE SYSTEM ON
NO
• REMOTE SYSTEM WIRE
SHORTING OUT
• MINIMUM MILLIVOLT:
• FLAME ENGULFING
THERMOPILE/THERMOCOUPLE
• VALVE IS IN ON POSITION
- 30 -
• SHUTOFF VALVE OPEN
• CONFIRM GAS HOOK-UP
OPEN CIRCUIT 18MV
CLOSED CIRCUIT 5MV
OPEN CIRCUIT 300MV
CLOSED CIRCUIT 165MV