Rheem Water Heater Error Codes & Fix Guides
All FixCode Guide coverage for Rheem water heater error codes: start with the complete code list, or jump to a deep-dive guide for a specific code. Everything is verified against Rheem manufacturer documentation.
Guides in this section
Rheem Water Heater Error Codes List: Every Code ExplainedRheem Tankless Error Code 11: No Ignition — Meaning, Causes & FixRheem Tankless Error Code 12: Flame Failure — Meaning, Causes & FixRheem Water Heater Blinking Light Codes: Red, Blue & Flash CountsRheem Tankless Error Code 29: Meaning, Causes & FixRheem Tankless Combustion Codes 13 & 17: Meaning & FixesRheem Tankless Error Code E5: Meaning, Causes & FixRheem Tankless Sensor & Flow Codes (E1, E3, E4, CL, P1): Meaning & FixesRheem Smart Tank Alarm Codes (A005, A105, AB): EcoNet & Hybrid GuideRheem Water Heater Reset: How to Reset & Clear Error Codes
Most searched Rheem water heater codes
| Code | Meaning |
|---|---|
| 11 | Rheem tankless (RTGH / RTG / IKONIC): flame not detected by the flame rod. At ignition the unit tries to light twice, and if the flame rod never proves a flame, it shuts down and displays 11. The RTGH service chart gives the classic owner-level cause: the gas shut-off valve is not fully opened. |
| 12 | Rheem tankless (RTGH / RTG / IKONIC): flame detected, then lost. The burner lit and the flame rod proved flame, but the flame dropped out during operation; Rheem's manual states the unit counts these flame-loss incidents and displays 12 after 3 consecutive losses. The RTGH service chart gives the plain-language causes: gas service interrupted, or LP gas running low. |
| 29 | Rheem tankless, and the meaning depends on generation. On condensing IKONIC-era models: condensation is not draining from the collector — the built-in drain trap's electrode reports the trap full or unreadable. On RTGH condensing models the service chart says the neutralizer is clogged. On older RTG and Rheem Australia models, 29 meant heat exchanger outlet temperature too low. Identify your model before acting. |
| E5 | Rheem electric tankless (EcoSmart / RTEX platform): high flow rate. The water is moving through the heater faster than its elements can bring it to the set temperature, so the outlet runs lukewarm and the control reports E5. EcoSmart's troubleshooting guide — EcoSmart is Rheem's electric tankless division — lists E5 simply as 'high flow rate': a capacity report, not a failed part. |