Ideal DHW Temperature Sensor Out of Range

Ideal boiler displays C9 and may not provide stable hot water

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

Faulty DHW NTC thermistor, Poor contact with plate heat exchanger, Damaged cable, PCB fault

Safety first: Hot water components can be very hot. Internal work is for engineers only.

User steps:

Reset: Power cycle and reset once.
Check flow: Ensure adequate hot water flow at taps; very low flow can cause temperature swings.

If C9 persists, an engineer should test and replace the DHW NTC sensor and check wiring and PCB.

Hard 4/5

DHW NTC Thermistor

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