Safety first: Turn gas control knob to OFF and wait at least 5 minutes to clear any unburned gas before relighting.

Step 1 – Clean pilot assembly: Remove the burner access cover. Inspect the pilot flame; it should be blue and envelop the thermopile tip. If weak or yellow, clean the pilot orifice with compressed air (do not enlarge the orifice).
Step 2 – Check thermopile connections: Ensure the thermopile leads are tightly connected to the gas control valve terminals.
Step 3 – Test thermopile output (advanced): With the pilot lit, measure millivolts across the thermopile leads. Compare to Ruud specifications. Low output indicates a failing thermopile.
Step 4 – Replace thermopile: Turn gas OFF, remove the burner assembly, disconnect the thermopile from the gas control, and install a new OEM Ruud thermopile/pilot assembly. Reassemble and follow the lighting instructions.

If the pilot still will not stay lit, the gas control valve may be defective and should be replaced by a professional.

Ruud gas water heater status light flashes 1 time every 3 seconds; pilot will not stay lit.

Possible Causes