BoilerFaultCodesTechnical description
Overheat sensor overheating
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit, causing the safety sensors to shut the system down to prevent damage. The most common reasons are a failed pump that isn't moving water away from the heat exchanger quickly enough, or a buildup of debris and sludge that has physically blocked the internal pipework.
This issue often comes to light during the first cold spell of autumn when the heating is turned back on after being idle all summer, 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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