BoilerFaultCodes.com
F18 Medium Lockout

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

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: User interface fault

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.

Typical repair cost £180-350 (including labour)

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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