BoilerFaultCodesTechnical description
Safety limiter in flow has tripped.
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety sensor to cut the power. It is usually caused by a pump failure that stops water from moving or a blockage in the system that prevents heat from being carried away fast enough. In some cases, air trapped in the heat exchanger can also cause a localized hotspot that trips the sensor.
This fault is more frequent in autumn when heating systems are first turned on after a long summer break, as pump components can seize due to inactivity.
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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