32 — Outgoing Water Thermistor Fault
The outlet water temperature sensor is open, shorted, or reading out of range.
- Keep using it?
- Yes, with caution
- DIY difficulty
- Moderate
- Verified against
- media.rinnai.us ↗
How to fix it
- Disconnect power.
- Locate the outgoing-water thermistor on the outlet manifold.
- Measure resistance and compare to the chart in the service manual.
- Inspect harness from sensor to PCB for damage and reseat connector.
- Replace thermistor if out of spec.
- If readings are good, replace the PCB.
Why it happens
Typical signs: Code 32 instead of running · Erratic temperature output · Unit won't modulate
- Failed outlet thermistor Sensor open or shorted.
- Loose or corroded connector Harness at PCB or sensor not tight.
- Damaged wiring Pinch, rodent, or moisture damage.
- PCB input failure Less common — board can't read sensor.
Parts you may need
If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.
- Outgoing water thermistor Common replacementAmazon →
More Rinnai tankless water heater codes
Frequently asked questions
What does the 32 code mean on a Rinnai tankless water heater?
The outlet water temperature sensor is open, shorted, or reading out of range.
What causes the 32 code on a Rinnai tankless water heater?
Failed outlet thermistor: Sensor open or shorted. Loose or corroded connector: Harness at PCB or sensor not tight. Damaged wiring: Pinch, rodent, or moisture damage.
Is it safe to keep using a Rinnai tankless water heater with a 32 error?
Yes, with caution. This is rated a moderate-severity fault.
How do I fix 32 on a Rinnai tankless water heater?
Disconnect power. Locate the outgoing-water thermistor on the outlet manifold. Measure resistance and compare to the chart in the service manual.
Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: media.rinnai.us.