Medium
F18 on Glow-worm Xtramax HE

Your boiler's control panel has stopped communicating with the main computer, meaning you cannot adjust settings or see what the boiler is doing.

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

User interface fault

From this model's manual
Verified against the Glow Worm Xtramax He installation & service manual, page 33.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the data link between the display screen and the boiler's internal computer is broken or interrupted. The most common cause is a loose connection or damaged wiring inside the unit, though a hardware failure on one of the circuit boards can also prevent the components from talking to each other.

DIY fix possible

Switch the boiler off at the main electrical fused spur switchWait for 30 secondsSwitch the power back on to see if the control screen resets and clears the error

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