Medium Lockout
S.06 on Glow-worm Ultracom 2 HXI

Your boiler's fan is continuing to run after it should have stopped, causing the system to pause for safety reasons.

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

fan overrun

What causes this fault?

This fault occurs when the boiler's control system detects that the fan is still spinning even though the heating or hot water demand has finished. The most common reason is a communication error between the fan and the main circuit board, or a sticking internal component that fails to cut power to the fan motor. For safety, the boiler will pause operation until it detects the fan has correctly stopped.

Engineer required

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

Find a Gas Safe engineer
Search the official register →

Related fault codes

Related guides you might find useful