F018 High
Your boiler has shut down because it cannot breathe properly, likely due to a blockage in the pipes leading to the outside of your home.
Technical description: Flue and / or air supply duct is blocked
Typical repair cost: £80-180 (including labour)
DIY fix possible
Check the external flue terminal on your outside wall for obstructions like bird nests, leaves, or debris.During freezing weather, check if the flue outlet is blocked by ice or snow and gently clear it.Reset the boiler by pressing the reset button once any external obstructions are removed.
Protect yourself from future repair bills
A boiler cover plan would cover faults like F018 — no call-out fees, no surprises.
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Parts commonly replaced
- Flue seals
- Fan assembly
- Air pressure switch
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