BoilerFaultCodesTechnical description
Temperature too high during central heating demand
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit because it isn't moving away from the heat exchanger properly. The most common reasons are a pump failure, a blockage caused by sludge and debris in the pipework, or air trapped within the system preventing flow.
This fault often appears during the first cold spell of autumn when the heating is turned back on after being idle for several months, which can cause internal pump parts to seize.
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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