Bradford-White Corp D-38T-155 Service Procedure D24-II, Pilot Operation Testing, 131

SERVICE PROCEDURE D24-II

Pilot Operation Testing

DANGER

120 volt exposure. To avoid personal injury, use caution while performing this procedure.

CAUTION

Be Careful When Making Voltage

Measurements or Jumping Terminals

Not to Damage or Deform Connectors or

Connector Pins.

Condition:

Pilot will not light or stay lit,

Error codes 62, or 63 shown on Water

Heater Display

Reset control by pressing the lower right button under “reset” on the display for 3 seconds. Does control board start ignition sequence and start sparking (sparking noise at pilot or at board)

Y

Is there spark at the pilot?

Y

Is there 22-27 volts AC output across terminal pins 8 & 2 on “Control” plug of Control Board? Carefully insert meter probe in wire plug to check pin terminals. Make sure control is in the trial for ignition sequence (see Sequence of Operation).

(see photo 13)

Y

Is there 22-27 volts AC input across

wire leads

“MV/PV” & “PV” (yellow & red wires)

at Gas Valve? (see photo 12)

N

Check wire harness for damage or loose connections. Repair or replace as needed.

Turn on power to the water heater

and verify proper operation

Check across “MV/PV” & “PV” Wire

leads to gas valve

12

N

Replace control board

N	Check for:
	Loose or damaged ignition wire
	Grounded pilot electrode
	Damaged pilot.

N Replace control board.

	Loosen pilot tubing connection at
Y	the gas valve and soap test.		Check for clogged or kinked pilot
	Is there pilot gas flow out of the	Y
			tube, clogged pilot orifice. Clean
	gas valve? See pilot illustration
			or replace as needed.
	for pilot inspection. (Wires must
			(see “Pilot Burner Inspection”)
	be connected to gas valve during
	this test).
	N
	Tighten pilot tube connection at
	the gas valve. Check incoming
	gas pressure to water heater. if
	okay, replace gas valve

131

Checking for 24 volts output to pilot valve (yellow and red wire pin terminals) on control board “control” plug.

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