Rinnai · Tankless Water Heater Moderate

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
rinnai.us ↗

How to fix it

  1. Disconnect power.
  2. Locate the outgoing-water thermistor on the outlet manifold.
  3. Measure resistance and compare to the chart in the service manual.
  4. Inspect harness from sensor to PCB for damage and reseat connector.
  5. Replace thermistor if out of spec.
  6. 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 replacement
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More Rinnai tankless water heater codes

02 02 — Power Interruption / Memory Loss 03 03 — Loss of Communication / EZConnect Issue 10 10 — Air Supply or Exhaust Blockage 11 11 — No Ignition 12 12 — Flame Failure 14 14 — Thermal Fuse / Overheat Cutoff

All Rinnai codes → All tankless water heater codes →

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: rinnai.us.