Bradford White Water Heater D75T1603N

Reset the control by holding the Lockout Reset button for 3 seconds and confirm the board starts the ignition sequence and sparks; replace the control board if it does not.

Confirm there is spark at the pilot; if not, check for a loose or damaged ignition wire, a grounded pilot electrode, or a damaged pilot.

Check for 22–27 VAC across control-board pins 8 and 2, and across the MV/PV and PV wire leads at the gas valve, replacing the control board or repairing the harness as indicated.

Loosen the pilot tubing connection at the gas valve and soap-test for pilot gas flow; check for a clogged or kinked pilot tube or orifice, or tighten the connection and replace the gas valve if inlet pressure is otherwise okay.

Flame rod shorted to ground (error code 57)

Pilot lights but no or low flame signal

D24-V Flue Baffle Removal, Inspection

Unplug the water heater from its electrical supply.

Disconnect the venting from the draft diverter and remove the draft diverter.

Disconnect the flue damper from the wire harness and remove it from the top of the water heater.

If required, shut off the water supply and disconnect the top plumbing connection.

Remove the screws holding the jacket head and remove the jacket head, using a screwdriver to pry underneath if necessary.

Remove the insulation to expose the collector cover.

Remove the collector cover screws, chiseling away foam if needed to access them.

Remove the collector cover using a pipe wrench.

D24-I Thermostat Circuit Testing

Unplug or disconnect electrical power to the water heater

Check continuity of the wire harness to the affected sensor

Measure resistance of the wire harness

Is the harness resistance close to 0 ohms?

Check sensor resistance against the sensor resistance table

Is the sensor resistance close to the expected value for the measured water temperature?

Restore power and run the heater through a full heating cycle

D24-VI Anode Removal and Inspection

Unplug the water heater from its electrical supply and shut off the water supply.

Open a nearby hot water faucet to relieve tank pressure.

Reinstall the anode rods once inspection or replacement is complete.

Connect a hose to the drain valve, route it to an open drain, and drain at least 5 gallons.

Close the valve and disconnect the hose.

D24-IV Main Burner & Pilot Removal and Inspection

WARNING — Heater components can be hot during this procedure; take precautions to avoid injury.

Unplug the water heater from its electrical supply.

Turn off the gas supply and rotate the gas valve control knob to OFF.

Disconnect the gas supply line and the gas valve wire leads.

Disconnect the white flame-sense wire and orange ignition wire from the control board.

Remove the two burner rack mounting screws and slide the burner rack out of the heater.

To reinstall, reverse the removal steps, then check for gas leaks and verify proper operation.