Bradford White UCG100H199 Installation & Operation Manual page 42

Step 7. Press "Done" to exit Diagnostic Mode and return to the DHW setpoint in User Mode.
The ICON control system can produce soft and hard lockouts. Soft lockouts are displayed if active
and are not stored in Diagnostic Mode history. The control will periodically attempt to resume
normal operation when in soft lockout conditions. If the system resumes normal operation a soft
lockout will clear instantly. Hard lockouts will display if active and will also be stored in Diagnostic
Mode History. Up to ten previous Hard lockouts are logged in Service Mode history, these cannot
be cleared from the log.
Service Error Codes and Troubleshooting Procedures
Definition
Error Code
of Code
No code –
blank
display
Internal
3-48, 58-60
Faults
Voltage
49 too low or
high
AC Inputs
53 phase
reversed
Fan speed
62
not proved
ILK Off
67 (Interlock
Off)
NOTICE
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.
• Verify wiring to the wiring diagram.
• Check power supply to make sure voltage and frequency is correct.
• Check for 24 volts from the transformer to the control board.
• Reset module by interrupting power or pressing the reset button on the module.
• Measure the incoming line voltage.
• Voltage should be 115-125 volts.
• If the voltage is not within this range or there is drastic fluctuation, then have the
incoming power supply checked.
• If the line voltage is satisfactory, check the output from the transformer to make
sure it is 22-26 volts.
• Replace transformer or wiring if defective.
• Check the module and display connections.
• Check the module power supply and make sure that frequency, voltage and VA
capacity of the transformer meet specifications.
• Check to make sure the wiring connections on the control module from terminals
J4-10 and J8-2 are connected together.
• Check the PWM wire harness connection from the blower to the control module.
• Make sure the pin terminals make solid contact.
• Measure the resistance of each wire in the wire harness from the terminal ends.
• Replace wire harness if defective.
• Check wiring to the normally closed blocked vent pressure switches and vent limit
switch.
• Use a voltmeter to find out if either pressure switch or the high limit switch has
opened.
• If so, determine the cause (blocked vent terminal, clogged condensate drain, high
temperature in compartment).
• If limit switches are closed, check wiring for shorts.
• Measure continuity.
• If limit switches and wiring check O.K., replace control module.
42
LOG?
NO
YES
YES
YES
NO
YES