Medium
H. on Halstead Wickes 80

Your boiler has accidentally entered a testing mode used by engineers, which means it is currently operating at a very low power setting and may not provide enough heat or hot water.

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.

Technical description

SERVICE mode (flashing H.) - appliance runs at minimum CH output

Engineer required

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

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