BoilerFaultCodesYour boiler has lost its electrical power supply or there is a fault with the incoming electricity to the unit.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Check the mains supply.
What causes this fault?
This fault occurs when the boiler's control system detects a total loss of incoming electrical power. The most common reason is a blown fuse on the circuit board or a tripped switch at the main fuse box, though it can also be caused by a faulty wall switch or a failure in the boiler's internal wiring.
This fault is occasionally more frequent during the winter months when power surges or local grid instability are more likely due to heavy electrical demand and adverse weather.
DIY fix possible
Check if other appliances in the house have powerCheck your home's consumer unit (fuse box) to see if a circuit breaker has trippedEnsure the boiler's isolation switch (usually located near the boiler) is turned onCheck if your pre-payment meter (if applicable) has credit
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 40 — no call-out fees, no surprises.
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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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