BoilerFaultCodesYour boiler's internal computer has encountered a memory or electrical glitch and has temporarily locked itself down to prevent safety issues.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Printed circuit board (PCB) lockout error
What causes this fault?
This fault occurs when the boiler's control board experiences a communication failure or an internal memory error, often caused by unstable electrical supply or aging components. It essentially means the boiler is 'confused' by inconsistent data and has shut down as a safety precaution to avoid operating unpredictably.
This fault is more common during winter months or stormy weather, as power surges, local grid fluctuations, and damp conditions can interfere with sensitive electrical components.
DIY fix possible
Locate the selector switch on the front of the boilerTurn the switch to the 'R' (Reset) position and hold for 5 secondsRelease the switch and wait for the boiler to attempt a restart
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E168 — no call-out fees, no surprises.
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Baxi Duo-tec/Megaflo is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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