Rinnai Rinnai V75iN Value Series Tankless Water Heater 32 Error Fix: Outgoing Thermistor Failure

Error code 32 on the Rinnai Rinnai V75iN Value Series Tankless Water Heater means: Outgoing Thermistor Failure. The outgoing (hot) water temperature sensor has failed or is reading out of range. The outlet thermistor measures the temperature of heated water leaving the unit. This is the primary feedback sensor for temperature control — the control board modulates the gas valve and bypass servo valve based on the outlet temperature reading to maintain the user's set temperature. Error 32 means this critical sensor has failed. Without it, the unit cannot regulate water temperature safely and will shut down. Diagnosis is the same as for the inlet thermistor (code 31) — check resistance with a multimeter. The outlet thermistor is located on the hot water outlet pipe inside the unit. Same replacement procedure and similar cost as the inlet thermistor. Because the outlet thermistor directly controls the temperature of water delivered to fixtures, this code should be addressed promptly to prevent temperature-related safety issues.

The most successful fix is "Test and Replace the Outgoing Thermistor Sensor" (hard difficulty, ~60 minutes). Estimated DIY cost: $15-$25. 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 the Outgoing Thermistor Sensor") is rated hard difficulty and takes about 60 minutes. Tools needed: T20 Torx screwdriver, Digital multimeter, Needle-nose pliers.

DIY cost: $15-$25. Professional repair typically costs $120-$180. Many homeowners save money by trying the top-ranked community fix first.

The Rinnai Rinnai V75iN 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 32 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.