Boiler shows E05, heating and hot water unavailable, temperature reading may be erratic

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.

Possible Causes

Open or short-circuit Baxi flow NTC sensor, Loose or corroded NTC connector, Damaged wiring harness to NTC, Faulty PCB input channel

Safety first: Isolate power before touching any internal wiring.

User checks:

Turn the boiler off and on at the fused spur to clear any temporary electronic glitch.
Check that the system pressure is correct (1.0–1.5 bar) and that radiators are not excessively hot when the fault appears.

When to call an engineer:

If E05 reappears immediately after power cycling.
The engineer will test the flow NTC sensor resistance, inspect the plug and wiring, and replace the sensor if out of specification.
If the NTC is correct, the PCB may require replacement.

Medium 3/5

Flow NTC Temperature Sensor

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