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CAUTION
Use Caution Not to Damage Connectors when making Voltage Measurements or Jumping Terminals
Water Heater Fault: Water heater does not operate
Display Error Code: Water heater display does not operate - blank display
Check main power supply to water
heater - fuse, circuit breaker, plug
receptacle, line cord or wiring to
water heater.
C
heck to make sure switch on top of
c
ontrol panel is in the ON position
Verify Primary and Secondary
voltage at the control board.
Voltage at primary pins 1&3 (white and
black wires) should be 110-120. If not,
check Line In pins 1&4. Check line cord
with ohmeter. Replace line cord if
defective.
If there is not 24 volts at Secondary
pins on the control board, check
transformer. Replace transformer
or wire harness.
Does water heater display operate?
Does damper begin to open?
Increase thermostat setting if tank is
warm and make sure the control
display status reads “Heating”.
Check wire connections of
board to display. See
illustration.
With the control cover tilted down,
measure the voltage between red and
black wire pin connections to display.
Voltage should be 24 volts AC
measured at the back of the Control
Display.
If no voltage at Display, check wire
harnesses and voltage at E-com
screw terminals (see photo 5).
Replace display if voltage is present at
display pin terminals. Replace control
board if no voltage is present at E-
com terminals (1&3, white-black wires
and 1&2, white-red wires) to display.
N
Y
See next page
Checking primary voltage to
transformer from board. Pins to
black and white wires.
Checking line voltage to board.
Pins to black and white wires.
Checking secondary voltage from
transformer. Pins to blue and yellow
wires.
Checking transformer voltage, front
terminals are 24 volts, rear terminals
are 120 volts.
Page 7
Troubleshooting
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