Bradford-White Corp D-38T-155 Troubleshooting, Pins to black and white wires, Defective

Troubleshooting

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	1
heater - fuse, circuit breaker, plug
receptacle, line cord or wiring to
water heater.
Check to make sure switch on top of
control panel is in the ON position		Checking line voltage to board.
		Pins to black and white wires.
		Voltage at primary pins 1&3 (white and
Verify Primary and Secondary		black wires) should be 110-120. If not,
voltage at the control board.		check Line In pins 1&4. Check line cord
		with ohmeter. Replace line cord if
		defective.

2

Checking primary voltage to

transformer from board. Pins to

black and white wires.

3 4

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”.

Y

See next page

Checking secondary voltage from transformer. Pins to blue and yellow wires.

NCheck wire connections of

board to display. See

illustration.

5

Checking transformer voltage, front terminals are 24 volts, rear terminals are 120 volts.

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.

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