BoilerFaultCodesYour boiler has sensed that the water inside has become or stayed too hot, causing it to shut down as a safety precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Temperature too high (overheat)
What causes this fault?
This fault occurs when water cannot flow through the boiler quickly enough to carry away the heat produced by the burner, leading to a rapid rise in temperature. The most common reasons are a failed pump that isn't pushing water around, or a buildup of sludge and debris that has created a blockage in the heat exchanger.
This issue often surfaces during the first cold snap of autumn when the heating is turned on after being dormant all summer, which can cause internal pump components to seize.
DIY fix possible
Check that all radiator valves are fully open to allow water to flow.Ensure your system pressure is between 1 and 1.5 bar on the gauge.Press the 'Reset' button on the boiler control panel once the unit has cooled down.
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 1 — 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.