Rinnai Rinnai V65iN Value Series Tankless Water Heater 79 Error Fix: Current Sensor Failure

Error code 79 on the Rinnai Rinnai V65iN Value Series Tankless Water Heater means: Current Sensor Failure. The internal current sensor on the control board is reporting abnormal readings. Rinnai units have a current-sensing circuit that monitors electrical current draw of key components (fan motor, gas valve solenoids, servo motors). Error 79 indicates this sensing circuit is malfunctioning — the current transformer or sensing resistor on the board may have failed. This prevents the control board from monitoring component operation for safety. Power-cycle the unit. If error 79 persists, the control board needs replacement. This is an uncommon error code that points specifically to a board-level component failure rather than an external component issue.

The most successful fix is "Test and Replace Control Board Due to Current Sensor Failure" (hard difficulty, ~60 minutes). Estimated DIY cost: $0-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated warning severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Test and Replace Control Board Due to Current Sensor Failure") is rated hard difficulty and takes about 60 minutes. Tools needed: Phillips screwdriver, Multimeter, Anti-static wrist strap.

DIY cost: $0-$20. Professional repair typically costs $400-$600. Many homeowners save money by trying the top-ranked community fix first.

The Rinnai Rinnai V65iN Value Series Tankless Water Heater has 8 other known error codes, including: 02 (Ignition Failure), 03 (Bath Fill Function Abnormality), 05 (Blocked Exhaust / Air Supply), 10 (Blocked Exhaust — Air Pressure Switch), 11 (No Ignition), and 3 more.

Error code 79 also appears on 8 other Rinnai models: Rinnai RE180iN RE Series Non-Condensing Tankless Water Heater, Rinnai RL75iN RL Series Tankless Water Heater, Rinnai RL94iN RL Series Tankless Water Heater, Rinnai RSC160iN Condensing Combi Boiler, Rinnai RU130iN Sensei Super High Efficiency Plus Tankless Water Heater, Rinnai RU199iN Sensei Super High Efficiency Plus Tankless Water Heater, and 2 more. The fix may vary by model, so check each model's specific page for tailored repair steps.