Rheem Gas Control or Valve Failure: Signs and Codes

The Short Answer: Rheem’s gas controls report their own failure with a status-light code: seven red flashes on atmospheric models, and several “replace the gas control” codes on power-vent models. Many other problems look like a bad gas control, though, including a pilot that’s out, a weak thermopile, or a clogged air intake. A technician should confirm the control has failed before it is replaced.

Codes that point to the gas control

Atmospheric codes come from Rheem’s Use & Care manual AP23698 (opens in a new tab). Power-vent codes come from the power vent manual AP23057 (opens in a new tab). Older Rheem, Ruud, and Richmond controls may use different patterns, so check the label on your heater.

Problems that look like a bad gas control

Before a control is replaced, these causes need to be ruled out:

• No status light at all: usually the pilot is out or the thermopile isn’t producing enough power. See Rheem water heater no status light.
• 2 red flashes: low thermopile voltage. See Rheem thermopile voltage low.
• 4 red flashes: the high-temperature limit tripped. The control may be fine; something caused overheating.
• 9 or 10 red flashes: chamber sensor or chamber temperature, usually an air or venting issue. See Rheem 9 red flashes.
• No gas: a closed supply valve or an empty propane tank stops everything.

What you can check safely

1. Write down the color and number of flashes over two full cycles.
2. Confirm the gas supply valve is open and other gas appliances work.
3. Check the control knob position and the temperature setting.
4. If the light is off, relight the pilot once following the label on the heater.
5. Keep the area around the base clear and free of flammable products.

What the technician will check

A technician will confirm the code, measure thermopile output and check its connection, and check gas pressure. On power-vent models they also check the blower, pressure switch, and the 120-volt supply. Only when power and inputs are good and the control still reports a fault, or won’t respond, do they replace it. Afterwards they leak-test the gas connections, relight, and confirm normal operation.

Repair or replace

A gas control is a significant part, but on a heater in good condition replacing it is usually worthwhile. If the tank is old, rusty at the base, or leaking, put the money toward a new heater instead. Ask the technician whether the control is still covered by your parts warranty; the rating plate and serial number will tell them.

Related: water heater gas valve electronic fault detected and Rheem 7 flashes.

Frequently Asked Questions

Q: Can a gas control fail without a code? A: Yes. A control that stays dark with a good pilot and thermopile, or won’t open the main burner when it should, may have failed. A technician has to test it to be sure.

Q: Can I replace a Rheem gas control myself? A: No. It involves disconnecting and reconnecting gas piping and must be leak-tested. It’s a job for a licensed technician.

Q: Why would a gas control fail? A: Age, heat, moisture from leaks or condensation, and electrical damage are common reasons. If water dripped on the control, the source of the water should be fixed too.