F7 High
Your boiler has stopped working because the electricity supply coming into your home is currently too weak to power the internal electronics safely.
Technical description: Low mains voltage – contact electricity provider.
Typical repair cost: £0-250 (including labour)
DIY fix possible
Check if other appliances or lights in your home are flickering or dimmingSwitch the boiler off and back on at the fused spur switch to see if the error clearsContact your regional electricity distribution network operator (DNO) to report a local supply issue
Protect yourself from future repair bills
A boiler cover plan would cover faults like F7 — no call-out fees, no surprises.
*Affiliate links — we may earn a commission at no extra cost to you. Prices shown are starting prices.
Parts commonly replaced
- None (External supply issue)
- Printed Circuit Board (PCB)
*Affiliate links — we may earn a commission at no extra cost to you.