Riello NXHM fault H5

Room temp. sensor (ta) fault

Heat pump

What it means

Fault with the room temperature sensor Ta.

Likely causes

  1. Sensor resistance out of range
  2. Ta sensor interface issue
  3. Ta sensor failure

Where to start

  1. Check the resistance of the sensor
  2. Check the Ta sensor interface connection

The full answer, free

  • How to put it right, step by step
  • The manual page for this fault (page 65), right under the answer

Safety: Isolate the heat pump and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.

From the Riello manual for the NXHM. Check the model on the data plate before you order parts.

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