Bradford White UCG100H199 Installation & Operation Manual page 55

DIAGNOSTIC ERROR CODES AND TROUBLESHOOTING PROCEDURES FOR EF MODELS
WITH HONEYWELL INTEGRATED DIRECT SPARK IGNITON CONTROL SYSTEM
Error
Definition of Code
Code
No code –
blank
display
Low Flame Sense
4
Current
Flame Sensed Out of
Normal Sequence
6 (Before Opening Gas
Valve or After
Closing Gas Valve)
Flame Detected
23
Before Ignition
Flame Detected After
24 Heating Cycle
Completes
Exhaust Vent Limit
26
Switch Open
Sensor Reading
32
Faulty
Flame Rod Shorted
57
to Ground
AC Line Frequency
Error – Signal Too
58
Noisy or Frequency
Incorrect
Line Voltage Too
59
Low or High
DC Output Voltage
61
Unstable
Cause of Problem and Actions Taken to Correct
 Check power supply to the water heater.
 Make sure water heater is plugged in and the breaker is on.
 Check if there is 120 volts power supply to the LINE connections on the
control board.
 If 120 volts is present, check for 24 volts output to SECONDARY terminals on
the Control Board.
 Check for loose wires, defective transformer.
 Check wire harness connections from display to the control board.
 Determine flame sense current in the Service Mode with the water heater
operating.
 If less than 4.0 microamps, check burner flame sense rod and wire.
 Clean flame sense rod with emery cloth.
 If problem is not solved, check for debris clogging burner or replace flame
sense rod.
 Check to make sure gas valve has closed.
 No voltage should be present at the gas valve before or after ignition cycle.
 Make sure wire positions on the wire harness are correct.
 If gas valve is stuck open, replace.
 Check to make sure gas valve has closed.
 No voltage should be present at the gas valve before the ignition cycle.
 Make sure wire positions on the wire harness are correct.
 If gas valve is stuck open, replace.
 Check to make sure gas valve has closed.
 No voltage should be present at the gas valve before the ignition cycle.
 Make sure wire positions on the wire harness are correct.
 If gas valve is stuck open, replace.
 Check to see if the exhaust vent high limit switch, located on the draft hood
has opened.
 Depress the red manual reset button on the high limit switch.
 If it resets with a "click", the switch has opened.
 Check for evidence of blockage in the exhaust vent.
 If there is evidence of blockage in the exhaust, call your Plumbing
Professional to the clear blockage.
 Do not continue to operate the water heater with the blockage in the exhaust
vent.
 Resistance of sensor out of operating range.
 Check continuity of wire harness to sensor, and if O.K., replace sensor.
 Pilot flame sensor rod is shorted to ground.
 Check to see if flame sensor wire has bare spots touching metal parts of if
flame sensor rod is touching the burner or other metal parts.
 Replace if flame sense wire is damaged or flame rod is bent.
 Check line voltage frequency to the water heater.
 Determine if there are wide fluctuations.
 Call an electrician if the problem persists.
 The water heater should be on a separate line.
 Check line voltage to the water heater.
 Determine cause of low or high voltage.
 Call an electrician or your utility.
 The water heater should be on a separate line.
 Check line voltage to the water heater for erratic readings.
 Also check wiring to make sure there are no shorts.
 If power supply and wiring are O.K., replace control board.
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