Service Manual

UTTW SERVICE PROCEDURE VII
Gas Control Testing and Replacement
R
Gas Control Replacement
Step1. Rotate knob of the gas control
to the “OFF” position.
Step 2. Turn off gassupply towater heater.
Step3.Disconnect gassupply line from gas control.
Step4.Turn off watersupply and drain water heater completely.
St
ep5.Remove the wire clip from the feedline.
Step6.Disconnect main burner feedline, pilottube,white thermopile wireand igniter wire from gas control and bend
the main burner feedlineand pilottube out of the
way. Alsodisconnectthe redwire leading from the thermopile
from the redwire leading from the gas control.
Step7. Remove the gas control from the water heater by rotating counter-clockwise.I
t maybe necessary tousealength
of ½” NPT pipe threaded into the inlet of the gas control.
Step8.Install newgas control into the water heater.
a)Install gas control intowater heater by rotating clockwise.DONOT useawrench on the gas contr
ol
body or damage to the gas control may occur.Ifnecessary, use a length of ½” NPT pipe threaded into
gas inlet of gas control.
b) Position the main burner feedlineand pilottube back to the gas control and attach to the gas control.
Connec
tthe igniter wireand the white thermopile wire to the gas control. Connectthe redwire from
the gas control to the resettable thermal switch and connectthe redwire from the
thermopile to the
resettable thermal switch.
c) Gatherthe igniter wire, white thermopile wireand red thermopile wire nearthe side of the feedline.
Use the clip that wasr
emovedinStep5to secure the wiresto the feedline.
d) Connect gassupply to inlet of gas control.
Step9.Resume the watersupply to the water heater.Be sure thatthe tank is full before
operation isresumed.
Step 10. Check the main burner feedlineand pilot feedline for gas leaks.
Step 10. To resume operation follow the instructions locatedonthe lighting instruction labelorthe lighting
instr
uctions locatedinthe installation and operation manual.
Igniter wire
Pilot tube
White thermopile
wire
Main burner
feedline
Red Wire Leads
Gas Control shown in the “OFF” position
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