BoilerFaultCodesTechnical description
Maximum temperature rise slope
What causes this fault?
This fault occurs when the internal sensors detect the heat exchanger is getting too hot, too fast. It usually means the water is trapped or moving too slowly to carry the heat away, often caused by a failing pump or a blockage in the system pipes. Essentially, the boiler is producing heat but has nowhere for it to go, so it shuts down to prevent damage.
This fault is more common when the heating is first switched on after summer, as pump components can seize up during long periods of inactivity.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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