E2
Junkers Flow NTC sensor open or short circuit

Boiler displays E2; flow temperature sensor error

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 flow NTC, Shorted or broken sensor wiring, Corroded connector at NTC or PCB, Water ingress into sensor connection

How to Fix / Troubleshooting

Safety: Isolate power before accessing internal components.

  • Reset boiler: Turn off and on again to see if E2 clears temporarily.
  • Inspect sensor connection: Locate the flow NTC on the flow pipe and check that the connector is firmly seated and dry.
  • Check wiring: Look for damaged insulation or pinched cables between the sensor and the control board.
  • Technician steps:
    • Measure NTC resistance at ambient temperature and compare with Junkers chart.
    • Check continuity of the cable harness.
    • Replace the flow NTC if readings are out of range or intermittent.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Flow NTC Temperature Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements