BoilerFaultCodesYour boiler has sensed a temperature issue and has likely locked out to prevent overheating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Neon indicators for Central Heating and Hot Water (0 to 4 bar gauge reference)
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the water temperature has risen too quickly or exceeded safe limits. The most common reason is a lack of water circulation, often caused by a failing pump or a blockage in the system preventing heat from being moved away from the burner.
This issue frequently appears during the first cold spell of autumn when the pump may have seized after being inactive throughout the summer.
DIY fix possible
Turn the selector switch to the reset position for five seconds and then back to your desired settingCheck that your radiator valves are open and not blockedEnsure the system pressure on the gauge is between 1 and 1.5 bar
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 Temperature Control — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Potterton Performa 24 is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.