Heater Control Board Diagnostic Led Interpretation And Troubleshooting - A.O. Smith Master-Fit 100 Series Service Handbook

HEATER CONTROL BOARD DIAGNOSTIC LED INTERPRETATION AND
TROUBLESHOOTING
TEST 1 - 120 VAC CHECK TO HEATER:
• No Green display "Power" LED On.
• Plugs are in receptacles.
• Supply power breaker is not "open".
• On/Off heater switch is "On".
TEST 1
IF.........
Voltage is not present from on/off
switch center black wire to ground
Power is present from center on/off
terminal
Voltage is not present at E13 to
ground
Power is present at E13
Voltage is not present from water
heater control receptacle E2 black to
ground
Power is present at E2
THEN............
Check conditions above.
Check wiring from switch to break box.
Check power from on/off switch to ignition board terminal E13.
Check wiring from on/off. Left-outside terminal to E13.
Replace on/off switch.
Check power from E14 to water heater control E2 receptacle.
Check wiring from ignition control board E14 to water heater
control receptacle E2.
Replace ignition control board.
Green LED should be on.
Servicing should only be performed by a Qualified Service Technician
120 VAC check to water heater ON/OFF switch.
Check for 115-125 VAC black wire to ground\
115 VAC check to E13 Terminal and 2B receptacle.
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