E05 High

Main E05 Fault Code

The Main E05 fault code means: your boiler's temperature sensor is sending an incorrect or missing signal, which causes the system to stop heating for safety reasons.. It appears on 1 Main model in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Flow NTC fault
Typical repair cost £120-220 (including labour)

Engineer required

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

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Main models that show the E05 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Main E05 fault code information on this page is sourced and cross-checked against the official Main service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026