Service Manual

15
Troubleshooting
System Observation
Water Heater Fault: Water heater does NOT operate.
Display Error Code: Water heater digital display does
NOT operate - blank display.
Is 24-28 VAC present between
red and black wire pin
connections located on the front
of the control board terminal J3?
Verify secondary voltage at the control
board.
Refer to control board
illustration. Voltage at
connector location J8 across
blue and yellow wires should
be 24-28 VAC. If not, check
transformer. Replace
transformer if defective.
Does the water heater digital
display operate? Increase
thermostat setting if tank is warm.
Digital display
operates– see
next page.
Check main power supply to water heater.
Check fuse, circuit breaker, plug receptacle, line
cord, and wiring to water heater.
Check to make sure switch on front of control
board is in the ON position.
Replace
digital
display.
Replace
control board.
Check wire harness
for proper continuity.
Check wires for proper
termination to control board. Are
wire terminations connected
properly to digital display?
Y
N
Y
N
Y
Y
Refer to control board
illustration. Voltage at
transformer across black and
white wires should be 110-120
VAC. Verify 120V from the
power switch.
Verify primary voltage at the transformer.
WARNING
120 volt potential exposure. Use caution making
voltage checks to avoid personal injury.
CAUTION
Use caution to NOT damage connectors when
making voltage measurements or jumping terminals.
Black & White
wires
Yellow & Blue
wires
ICON Control Board Schematic
15