27
Removing and Replacing the Gas
Control Valve/Thermostat
IMPORTANT:
The gas control valve/thermostat is a standard
valve with wire leads that connect to the thermopile.
Removing the Gas Control Valve/Thermostat:
1. Turn the gas control/temperature knob to the “OFF”
position (Figure 18).
2. Turn off the gas at the manual shut-off valve on the gas
supply pipe (Figure 3).
3. Drain the water heater. Refer to the section of “Draining
and Flushing” and follow the procedure.
4. Disconnect the igniter wire from the igniter lead wire.
Disconnect the temperature sensor wire. Disconnect
the red (+) and white (-) thermopile wires. Disconnect
the pilot tube (7/16” wrench) and manifold tube (3/4”
wrench) at the gas control valve/thermostat (Figure 22).
5. Refer to “Gas Piping” (Figure 3) and disconnect the
ground joint union in the gas piping. Disconnect the
remaining pipe from the gas control valve/thermostat.
6. To remove the gas control valve/thermostat, thread a 4”
section of gas pipe into the inlet and use it to turn the
gas control valve/thermostat (counterclockwise.) Do not
use pipe wrench or equivalent to grip body. Damage
may result, causing leaks. Do not insert any sharp
objects into the inlet or outlet connections. Damage to
the gas control valve/thermostat may result.
Gas Control Valve/Thermostat:
To replace the gas control valve/thermostat, reassemble
in reverse order. When replacing the gas control valve/
thermostat, thread a section of 4” gas pipe into the inlet and
use it to turn the gas control valve/thermostat (clockwise.)
DO NOT OVER TIGHTEN, damage may result.
•
Be sure to use approved Teflon® tape or pipe joint
compound on the gas piping connections and fitting on
the back of the gas control valve that screws into tank.
•
Be sure to remove the pilot ferrule nut from the new gas
control valve/thermostat.
•
Turn the gas supply on and check for leaks. Test the
water heater by brushing on an approved noncorrosive
leak detection solution. Bubbles forming indicate a leak.
Correct any leak found.
•
Be sure tank is completely filled with water before
lighting and activating the water heater. Follow the
“Lighting Instructions” on page 18.
•
If additional information is required, reference the
number on the cover of this manual for service information.
Operational Checklist
TROUBLESHOOTING CHART
4. No leaks at pilot and manifold connection.
5. Manifold door screws securely tightened.
1. Manifold gasket properly sealed.
2. Viewport not damaged or cracked.
3. Manifold component block properly installed.
PROBLEM
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
BURNER WILL NOT IGNITE
1. Pilot not lit
2. Thermostat set too low
3. No
gas
4. Dirt in the gas lines
5. Pilot line clogged
6. Main burner line clogged
7. Non-functioning
thermopile
8. Non-functioning
thermostat
9. Heater installed in a confined area
1. Light
pilot
2. Turn temp. dial to desired temperature
3. Check with gas utility company
4. Notify utility-install trap in gas line
5. Clean, locate source and correct
6. Clean, locate source and correct
7. Replace
thermopile
8. Replace
thermostat
9. Provide fresh air ventilation
SMELLY WATER
1. Sulfides in the water
1. Replace the anode with a special anode
BURNER FLAME
YELLOW-LAZY
1. Insufficient secondary air
2. Low gas pressure
3. Flue
clogged
4. Main burner line clogged
5. Obstruction in main burner orifice
1. Provide ventilation to water heater
2. Check with gas utility company
3. Clean, locate source and correct
4. Clean, locate source and correct
5. Clean or replace orifice
PILOT WILL NOT LIGHT OR
REMAIN LIT
1. Non-functioning
igniter
2. Thermopile connection loose
3. Air in gas line
4. Proper Lighting Sequence not followed.
Gas Control /Temperature Knob was not
held in for sufficient time
5. Low gas pressure
6. No
gas
7. Dirt in gas lines
8. Cold
drafts
9. Thermostat ECO switch open
10. Pilot line or orifice clogged
11. Non-functioning thermopile
1. Replace igniter pilot assembly
2. Seat connector firmly in socket
3. Bleed the air from the gas line
4. Do not attempt to relight if the red light is lit,
and the pilot flame is not visible through the
view port. Wait until the red light is no longer
lit, then follow lighting instructions on the water
heater
5. Check with gas utility company
6. Check with gas utility company
7. Notify utility-install dirt trap in gas line
8. Locate source and correct
9. Replace
thermostat
10. Clean, locate source and correct
11. Replace thermopile
