Bradford White UDH-75T-50FR-3N - Manual (Page 20)

SERVICE PROCEDURE V
Gas Control
Testing, Disassembly & Replacement
GAS CONTROL REPLACEMENT
Rotate knob counter-clockwise to
the “OFF” position.
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The Bradford White
Step 1. Rotate knob of the gas control
to the “OFF” position.
Step 2. Turn off gas supply to water heater.
Step 3. Disconnect gas supply line from gas control.
Step 4. Turn off water supply and drain water heater completely.
Step 5. Remove the wire clip from the feedline.
Step 6. Disconnect main burner feedline, pilot tube, white thermopile wire and igniter wire from gas control and bend
the main burner feedline and pilot tube out of the way. Also disconnect the red wire leading from the thermopile
from the red wire leading from the gas control.
Step 7. Remove the gas control from the water heater by rotating counter-clockwise. It may be necessary to use a length
of ½” NPT pipe threaded into the inlet of the gas control.
Step 8. Install new gas control into the water heater.
a) Install gas control into water heater by rotating clockwise. DO NOT use a wrench on the gas control
body or damage to the gas control may occur. If necessary, use a length of ½” NPT pipe threaded into
gas inlet of gas control.
b) Bend the main burner feedline and pilot tube back to the gas control and attach to the gas control.
Connect the igniter wire and the white thermopile wire to the gas control. Connect the red wire from
the gas control to the red wire from the thermopile.
c) Gather the igniter wire, white thermopile wire and red thermopile wire near the side of the feedline.
Use the clip that was removed in Step 5 to secure the wires to the feedline.
d) Connect gas supply to inlet of gas control.
Step 9. Resume the water supply to the water heater. Be sure that the tank is full before operation is resumed.
Step 10. To resume operation follow the instructions located on the lighting instruction label or the lighting
instructions located in the installation and operation manual.
Igniter wire
Pilot tube
White thermopile
wire
Main burner
feedline
Red gas control
wire
Red thermopile
wire
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