BoilerFaultCodesYour boiler is overheating because water isn't moving through the system quickly enough to carry the heat away.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Maximum water temperature: Rise in flow temperature too fast. Check: circulation pump; water flow through the unit; water pressure (0.8 bar min).
What causes this fault?
This fault occurs when the water temperature inside your boiler rises too quickly, causing the system to shut down for safety. The most common reasons are a pump that has failed to circulate water, a blockage in the pipework, or low water pressure, all of which prevent heat from being moved away from the burner. In some cases, air trapped in the system can also block the flow and trigger this overheat warning.
This fault is more common in autumn when heating systems are switched back on after being idle all summer, which can cause internal pump parts to seize.
DIY fix possible
Check that your system water pressure is at least 1.0 bar on the pressure gauge.Ensure all radiator valves and internal stopcocks are fully open to allow water flow.Bleed all radiators to remove trapped air that might be blocking the circulation.
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 2 5. — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Remeha W40 60 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.