22
Immergas Return Temperature Sensor (NTC) Fault

Boiler shows error 22, return temperature reading incorrect, boiler may shut down prematurely.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Defective return NTC sensor, Loose or corroded sensor connection, Damaged harness between sensor and PCB, PCB sensor input failure

How to Fix / Troubleshooting

Safety: Turn off power and allow the boiler to cool before working on sensors.

  • Locate return NTC: Find the return NTC on the return pipe or lower part of the heat exchanger. Ensure it is properly seated and clipped.
  • Check connections: Inspect and reseat the connector at the sensor and on the PCB. Look for corrosion or moisture.
  • Test sensor: Measure resistance at ambient temperature and compare with the Immergas NTC curve. Replace the sensor if readings are out of tolerance.
  • Inspect cable: Follow the cable route and check for cuts, pinching, or heat damage. Replace the harness if necessary.
  • PCB diagnosis: If all else is correct, the PCB may misread the sensor and need replacement.
  • System test: After repair, run the boiler and ensure stable operation without error 22.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Return NTC Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements