Known issue: Rheem / Ruud gas water heater flammable vapor (FV) sensor lockouts
Rheem and Ruud FVIR gas water heaters with electronic controls use a flammable vapor sensor near the base that locks out the burner when vapors are detected or when the sensor reads out of range. Rheem issued a technical bulletin about sensors whose resistance falls below the gas control's minimum, causing a lockout that only a replacement sensor clears. Genuine vapors (gasoline, solvents, some cleaners) can also trip it. Rheem sells the sensor as a replacement kit; techs replace a tripped sensor rather than try to reuse it.
Before you start
- If you smell gas, leave, do not touch switches, and call the gas utility from outside
- Never bypass or jumper the FV sensor
- Gas valve, burner, pilot assembly and venting work is for a licensed gas technician
Diagnostic steps
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