Rheem · Water heater
Status light: 3 flashes Water temperature not rising / sensor fault
What this code means
The control senses that water temperature isn't increasing as expected during a heating call, which usually points to a sensor or valve issue rather than an ignition failure.
Most likely causes
- Failed or miscalibrated temperature sensor
- Gas valve not fully opening
- Very high hot water demand outpacing recovery (less common trigger)
What to try first
This is a sensor/valve diagnosis, not something to troubleshoot by relighting the pilot.
Safety note: if this code returns after one clean reset, stop resetting it — repeated lockouts usually mean a real fault that needs a licensed technician. Never bypass a safety switch.
FAQ
What does Rheem error code Status light: 3 flashes mean?
Water temperature not rising / sensor fault. The control senses that water temperature isn't increasing as expected during a heating call, which usually points to a sensor or valve issue rather than an ignition failure.
Can I fix Rheem code Status light: 3 flashes myself?
Usually not. This is a sensor/valve diagnosis, not something to troubleshoot by relighting the pilot. If the code returns after one reset, it needs a licensed technician.
What causes Rheem code Status light: 3 flashes?
The most common causes are: failed or miscalibrated temperature sensor; gas valve not fully opening; very high hot water demand outpacing recovery (less common trigger).
Other Rheem water heater codes
All Rheem water heater error codes →
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This information may contain errors or not apply to your exact model — always double-check it against your appliance's own manual before acting. If there's any chance of a gas, fire, electrical, carbon monoxide, or other safety hazard, stop and call a licensed professional or the appropriate agency (e.g. your gas utility) instead of relying on this page alone.