Service Manual

6
White Rodgers Mechanical Gas Control Troubleshooting Chart
Flammable Vapor Ignition Resistant Water Heaters
Symptom Probable Cause Corrective Action
Service
Procedure
Pilot will not light
1. No incoming gas or too low
gas
pressure.
2. Gas control knob set to
wrong
position.
3. Gas control knob not being
fully
depressed when
attempting to light
pilot.
4. Pilot orifice or pilot tube is
obstructed
or kinked.
5. Pilot electrode not sparking to
pilot.
6. Piezo igniter not functioning.
1. Turn on gas supply and/or check
line
pressure.
2. Review lighting instruction. Set gas
control knob to
correct position.
3. Review lighting instruction. Fully
depress gas control knob.
4. Clean, repair or replace.
5. Verify correct electrode position.
Replace pilot assembly.
6. Replace piezo igniter.
1. See Service
Procedure
RG-V
2. See Service
Procedure
RG-III
3. See Service
Procedure
RG-III
4. See Service
Procedure
RG-IV
Pilot will not stay lit
when button is
released
1. Poor thermocouple
connection at
combination
thermostat/gas valve.
2. Thermocouple not fully
engaged in
pilot assembly
bracket.
3. Pilot flame is not fully
enveloping the
thermocouple
bulb.
4. Weak or defective
thermocouple.
5. Open ECO in
combination
thermostat/
gas valve.
6. Defective magnet in
combination
thermostat/gas
valve.
7. Resettable thermal switch
has
opened.
1. Check connection at combination
thermostat/gas valve. Proper
tightness should be finger tight
+ a 1/4 turn.
2. Inspect thermocouple to ensure
that it is fully engaged into pilot
bracket.
3. Clean pilot orifice and verify pilot
tube is clear; check gas supply
and line pressure.
4. Check thermocouple and replace
if necessary.
5. Check ECO continuity and replace
combination thermostat/gas valve
if necessary.
6. Check magnet operation and
replace combination
thermostat/gas valve if necessary.
7. Determine cause of switch
activation. To reset, depress
button on resettable thermal
switch located on inner door.
1. See Service
Procedure RG-II
2. See Service
Procedure RG-V
3. See Service
Procedure RG-V
Pilot will light but
the main
burner
will not come on
1. Combination thermostat/gas
valve set too
low for desired
water temperature.
2. Combination
thermostat/gas valve
temperature is satisfied.
3. Insufficient gas supply or
low gas
pressure.
4. Combination thermostat/gas
valve has
wide differential or
is out of calibration.
1. Adjust temperature dial on
combination thermostat/gas
valve.
2. Check temperature dial
setting on combination
thermostat/gas valve.
3. Check gas supply and line
pressure.
4. Check combination
thermostat/gas valve for
proper operation, replace if
necessary.
1. See Installation
and Operation
Manual.
2. See Service
Procedure RG-V
3. See Service
Procedure RG-V
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