BoilerFaultCodesTechnical description
Overheat fault
What causes this fault?
This fault occurs because the internal sensors have detected the water inside the boiler is reaching a dangerously high temperature, triggering an automatic shutdown to prevent damage. The most common reason is that the water isn't moving through the system quickly enough, often due to a failed pump, a blockage in the pipework, or a build-up of sludge in the heat exchanger.
This issue often surfaces during the first cold spell of autumn when the heating is turned back on after months of inactivity, as pumps can seize up during the summer.
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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