Rheem gas water heater status light: 1 blue blink every 3 seconds
Normal operation: the pilot is lit. If the temperature knob is still in the PILOT position, the heater is waiting for it to be set. Not a fault.
If you smell gas
Stop: do not relight or troubleshoot anything. Rheem’s own words (first page of both Use & Care Manuals, AP23060 and the Low NOx AP23698):
- Do not try to light any appliance.
- Do not touch any electrical switch; do not use any phone in your building.
- Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.
- If you cannot reach your gas supplier, call the fire department.
- Do not return to your home until authorized by the gas supplier or fire department.
Calling from a neighbor’s phone means leaving the building first.
What you see: one flash, then a pause, repeating. Applies to: Rheem residential atmospheric gas water heaters, 29 to 60 gallons, natural or LP gas — the manual linked from the Rheem Performance atmospheric XG40T06EC36U1 product page.
What it means
The manual’s wording: “One (1) blink every three (3) seconds — blue” — Rheem FVIR atmospheric models (AP23060).
Normal operation: the pilot is lit. If the temperature knob is still in the PILOT position, the heater is waiting for it to be set.
Not a fault.
What Rheem tells the owner to do
- Rheem says to set the temperature knob on the combination gas control to the desired setting.
semiatic gives no repair instructions of its own. The steps above are only the ones Rheem addresses to the owner in its manual.
When to call a qualified service agency
This pattern is normal operation. If the light shows a fault code instead, or you have no hot water with the light normal and the knob set correctly:
Rheem’s manual: “CAUTION: For your safety DO NOT attempt repair of gas piping, Combination Gas Control (Thermostat), burners, vent connectors or other safety devices. Refer repairs to qualified service personnel.” For service it says to contact your installer, plumbing contractor or previously agreed upon service agency first, then Rheem’s national service department on 1-800-432-8373 with the model and serial number from the rating plate.
Source
Rheem’s own manuals, read on the date shown.
- Rheem Manufacturing Company: Use & Care Manual with Installation Instructions — Water Heaters, Residential Gas, FVIR Certified (AP23060 Rev 01), “Combination Gas Control, Status Light Troubleshooting” — Rheem residential atmospheric gas water heaters, 29 to 60 gallons, natural or LP gas — the manual linked from the Rheem Performance atmospheric XG40T06EC36U1 product page. www.rheem.com Checked 2026-09-29.
- Rheem Manufacturing Company: Use & Care Manual with Installation Instructions — Water Heaters, Residential Gas, Low NOx Emissions (AP23698), “Gas control (Thermostat), Status Light Troubleshooting” — Rheem residential Low NOx (10 ng/J, SCAQMD Rule 1121) atmospheric gas water heaters, 29 to 55 gallons. files.myrheem.com Checked 2026-09-29.
The same pattern on other brands
The same count on another maker’s gas control can mean something else.