BoilerFaultCodesTechnical description
Safety temperature limiter by-pass
What causes this fault?
This fault occurs when the water inside the boiler gets too hot too quickly, triggering a safety sensor to shut the system down to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage in the heat exchanger that traps heat inside the unit.
This issue often surfaces during the first cold spell of autumn when a pump that has been idle all summer fails to restart.
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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