Rheem Waterheater Error Codes

All Rheem waterheater error codes with step-by-step troubleshooting, multimeter specs, and OEM part numbers.

3 error codes

Code	Meaning	Severity	Difficulty
11	Code 11 on a Rheem tankless water heater means the unit attempted to ignite the burner and failed after multiple tries. The control board detected no flame signal and shut down as a safety measure. highintermediate	high	intermediate
HUB	Rheem tankless water heaters display numeric error codes on the LCD when the unit detects a fault in the gas supply, ignition, venting, or sensor circuits. These codes help identify the specific failure before calling a technician. lowbeginner	low	beginner
NO-HOT-WATER	Gas, Electric, and Tankless Diagnosis mediumintermediate	medium	intermediate