Which models this covers
Rheem residential gas tank water heaters with a thermopile-powered gas control and status light (use and care manuals AP23698, AP22858 and AP19928). Codes differ between control boards, so check the code chart printed on your unit or in its manual if your model isn’t listed.
How to read the code
With the pilot lit, watch the status light on the front of the gas control and count the blinks before the pause. Blue blinks mean normal operation, and red blinks report a fault.
Status light codes
| Code | What it means | What to do |
|---|---|---|
| Off | Control is off, the pilot is out, or thermopile voltage is very low | Relight following the label instructions. Check the thermopile connector at the control. |
| Solid | Pilot went out recently, or the knob was just turned to OFF | Wait for the control to reset, then relight following the label. |
| 1 | Normal: pilot lit, knob at PILOT | Turn the knob to your temperature setting. |
| 2 | Low thermopile voltage with the pilot lit | Check that the thermopile connector and wires are secure. If it continues, call a pro.Pro |
| 4 | High water temperature limit tripped | Call a pro.Pro |
| 5 | Water temperature sensor failure | Call a pro.Pro |
| 7 | Gas control failure | Call a pro. The gas control usually needs replacing.Pro |
| 8 | False pilot flame signal (labeled “flame sense error” on some controls) | Call a pro.Pro |
| 9 | Combustion chamber sensor failure (on some Ultra Low NOx models, or a bimetal switch activated) | Call a pro.Pro |
| 10 | Combustion chamber temperature shutdown | Call a pro.Pro |
Sources
These codes are transcribed from the manufacturer’s own documentation. Many websites repeat codes that don’t match the manuals, so when in doubt, trust the chart on your unit.
- Rheem Use & Care Manual AP23698 (Residential Gas, 29–55 gal)
- Rheem Use & Care Manual AP22858 (FVIR)
- Rheem Use & Care Manual AP19928 (Ultra Low NOx)
Code pointing to a big repair? Check whether to repair or replace before you pay for it.
Frequently asked questions
What does 2 blinks mean on a Rheem water heater?
Two blinks means the thermopile isn’t producing enough voltage while the pilot is lit. Check that the thermopile connector at the gas control is firmly seated and the wires aren’t damaged. A weak or dirty pilot flame can also cause it. If the code continues, the thermopile likely needs replacing.
Why is there no status light on my Rheem water heater?
No light usually means the pilot is out or the control is off. Relight the pilot following the instructions on the heater’s label. The control needs the pilot lit to power the light.
Can I reset a Rheem water heater status code?
Turning the knob to OFF, waiting, and relighting will clear a code if the problem was temporary. A code that returns (especially 4, 5, 7, 8, 9 or 10) points to a fault that needs a technician.