Bradford White IGI-180R-10 Service Manual page 38

VI - TROUBLESHOOTING
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.
2) Is the flame rod normal ? Error "72" is displayed
3) Is the water temperature thermistor normal?
(cont.)
Checking the flame rod.
a. # Detach the flame rod terminal C1, and re-attempt
operation.
("72 is displayed)
Proceed to check item 3 below.
(no "72" displayed)
Inspect flame rod wiring for current leak and inspect
flame rod for carbon build-up.
Measure resistance between the flame rod
Terminal C1 and the appliance earth.
Normal: 1 M Ω or more.
If normal, replace the PCB unit.
Faulty: Replace the flame rod.
(Service Procedure IGI-2, page 49)
See page 42 for additional information and resistance values
pertaining to the flame rod.
If error "32" is displayed, check the water
temperature thermistor.
a. # Disconnect connector B5, and measure resistance of
the white ~ white wires.
Resistance > 1 M Ω = open circuit.
Resistance < 1 Ω = short circuit.
Normal: Proceed to check item 4 on the next page.
Faulty: Replace the water temperature thermistor.
(Service Procedure IGI-6, page 50)
See page 43 for additional information and
resistance readings pertaining to the
temperature themistor.
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