Paloma PH2-20R OFN Engineering Handbook page 41

SVC 820-Tankless Gas Trouble Shooting Manual
CONTROL BOARD Diagnostic Chart
All voltage checks must be performed while unit is attempting to go to main burner and Molex connector "K" IS
Measure DC voltage across black wire #6
and yellow wire #1 on connector "K":
90 – 120 DC Volts
Measure DC voltage across black wire #6
and white wire #2 on connector "K":
90 – 120 DC Volts
Measure DC voltage across black wire #6
and grey wire #3 on connector "K":
90 – 120 DC Volts
Measure DC voltage across black wire #6
and red wire #5 on connector "K":
90 – 120 DC Volts
Measure DC voltage across black wire #6
and blue wire #4 on connector "K":
90 – 120 DC Volts
Control Board is 'OK'
IF all components tested 'OK':
**CHECK GAS, VENTING, & GROUND**
connected to Control Board. Restart unit after each voltage check.
Is the voltage
NO
OK?
YES
Is the voltage
NO
OK?
YES
Is the voltage
NO
OK?
YES
Is the voltage
NO
OK?
YES
Is the voltage
NO
OK?
YES
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Replace Control Board
Replace Control Board
Replace Control Board
Replace Control Board
Replace PCB
41