BoilerFaultCodesYour boiler's internal control board is getting too hot, usually because it is located too close to a heat source or there is a fault with the electronics.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Electronic temperature error could be overheating due to external influences
What causes this fault?
This fault occurs when the boiler’s main electronic control board exceeds its safe operating temperature. It is usually caused by either an internal electrical component failing and generating excess heat, or the control box being exposed to high temperatures from nearby pipes or internal leaks. To prevent permanent damage to the electronics, the boiler shuts down as a safety precaution.
This issue may be more frequent during the summer months or in very warm utility rooms, as higher ambient temperatures make it harder for the internal electronics to stay cool.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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 F.65 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
Affiliate links — we may earn a commission at no extra cost to you.