BoilerFaultCodesTechnical description
Limit thermostat fault
What causes this fault?
This fault occurs when the water temperature inside your boiler exceeds a safe limit, triggering a safety switch to prevent damage. The most common reasons are a pump failure that stops water from moving or a buildup of debris that blocks the flow, causing the heat exchanger to overheat rapidly.
This error often appears when the heating is first turned on in autumn, as pump components can seize up after being idle during the summer months.
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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