E 78 High
Your boiler has reached its safety limit for monitoring the gas flame and cannot adjust itself correctly to heat your home.
Technical description: Regulation current value has been reached. Try resetting the boiler, check the gas pressure and check the combustion values and CO2 calibration – if this doesn’t work the board or valve needs replacing.
Typical repair cost: £120-£350 (including labour)
DIY fix possible
Press and hold the reset button for 3 secondsEnsure your gas meter has credit (if applicable)Check that other gas appliances in your home are working correctly
Protect yourself from future repair bills
A boiler cover plan would cover faults like E 78 — no call-out fees, no surprises.
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Parts commonly replaced
- Gas Valve
- Main Printed Circuit Board (PCB)
- Ionisation Electrode
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