E 40 High
Your boiler has detected an issue with the stability of the electrical power supply coming into your home.
Technical description: Electricity network frequency error – fluctuation in electricity frequency.
Typical repair cost: £90-350 (including labour)
DIY fix possible
Turn the boiler off using the power button or at the fused spur switchWait for 60 secondsTurn the power back on and check if the code clears as the local grid stabilizes
Protect yourself from future repair bills
A boiler cover plan would cover faults like E 40 — no call-out fees, no surprises.
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Parts commonly replaced
- Main PCB (Printed Circuit Board)
- Voltage Stabiliser (external)
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