BoilerFaultCodesYour boiler has detected that it is getting too hot too quickly, usually because water isn't moving through the system properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Maximum flow temperature value exceeded or insufficient circulation – temporary fault.
What causes this fault?
This fault occurs when the water inside the boiler heats up much faster than the system can carry it away, causing it to reach a dangerous temperature in seconds. This is usually caused by a pump failure, a blockage in the pipes, or trapped air, all of which prevent the water from circulating properly. Essentially, the boiler is producing heat but has nowhere to send it, so it shuts down to prevent internal damage.
This fault is more frequent in autumn when heating systems are switched back on after being idle, as pumps can seize up or debris can settle during the summer months.
DIY fix possible
Check that your boiler pressure is between 1 and 1.5 bar on the gauge.Ensure all radiator valves are fully open to allow water to flow.Restart the boiler to see if the temporary fault clears.
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A boiler cover plan would cover faults like H.01 – .14 — no call-out fees, no surprises.
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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.
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