Medium
OT ERROR on Remeha Avanta 28c

Your boiler's external temperature sensor and frost protection thermostat are sending conflicting signals to your heating controller.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Outside sensor used in conjunction with a frost thermostat connected parallel to the Celcia on connectors 7 and 8 on X9; when the frost thermostat calls for heat (contact closed) it will override the Celcia 20 control.

Shared across the Avanta Plus range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

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All 22 fault codes on the Avanta 28c

Seeing a different code? Every code this model can display, in one place.

89d5d8d9é0E01é1é2é3é4é5é6é7é8é10é11é13é43é44é45

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