Vermont Casting BHDR36 - Manual (Page 32)

- 32 -
TROUBLE SHOOTING THE GAS CONTROL SYSTEM
SIT 820 NOVA MILLIVOLT VALVE
START CHECK
GLASS DOOR TO BE REMOVED BEFORE SERVICE WORK
GAS SUPPLY ON
• SHUTOFF VALVE OPEN
• CONFIRM GAS HOOK-UP
LIGHT PILOT WITH
PIEZO IGNITION
• ELECTRODE GAP MIN. 1/8"
• ELECTRODE CRACKED
• ELECTRODE CABLE ATTACHED
• PIEZO IGNITOR GENERATES
SPARK
• ELECTRODE CABLE NOT
GROUNDED
PILOT STAYS ON
• FLAME ENGULFING
THERMOCOUPLE BY 3/8"
• THERMOCOUPLE ATTACHED
TO VALVE
• MNIMUM MILLIVOLT:
OPEN CIRCUIT 18MV
CLOSED CIRCUIT 5MV
• VENT SAFETY SWITCH TIGHT
AND NO SHORTS
(FOR UNITS EQUIPPED WITH
VENT SAFETY SWITCH)
MAIN BURNER ON
• REMOTE SYSTEM ON
• REMOTE SYSTEM WIRE
SHORTING OUT
• MINIMUM MILLIVOLT:
OPEN CIRCUIT 300MV
CLOSED CIRCUIT 165MV
• FLAME ENGULFING
THERMOPILE/THERMOCOUPLE
• VALVE IS IN ON POSITION
▼
▼
▼
▼
▼
▼ NO
NO
NO
YES
YES
▼
NO