ErrorCodePro · Appliance Error CodesRinnai Tankless Water Heater Error Codes: Full List & Meanings
Every Rinnai tankless water heater error code we have verified against Rinnai's own support pages, with its official meaning. This list covers sensei and non-sensei tankless water heaters. Codes vary by model, so confirm in your owner's manual. Support: Rinnai support, 1-800-621-9419.
Smell gas? Leave the building now. Do not touch light switches, phones or appliances inside. Call your gas utility or 911 from outside. CO alarm sounding or headache, dizziness or nausea? Get everyone outside and call 911. Gas valves, burners, venting and wiring are for a licensed technician only. See our safety policy.
Codes by system
Venting / airflow
Heating
All Rinnai tankless water heater error codes
Codes marked "Reset only" or "Service" have no separate page because the manufacturer publishes no owner fix beyond a reset or a service call.
| Code | Official meaning | System | Owner action |
|---|---|---|---|
| 10 | There's an air supply or exhaust blockage, or the condensate trap is full (the trap applies to SENSEI models only). | Venting / airflow | Owner checks |
| 11 | The burner didn't ignite. | Heating | Owner checks |
| 12 | The flame failed. | Heating | Owner checks |
| LC | Scale is building up in the heat exchanger. On non-SENSEI models, LC0–LC9 are the only codes that let the heater keep running, and the display alternates with the temperature. Also: LC0, LC1, LC2, LC3, LC4, LC5, LC6, LC7, LC8, LC9 | Heating | Owner checks |
Symptoms
Sources
Last reviewed: October 20, 2026. ErrorCodePro is not affiliated with Rinnai.