BoilerFaultCodesTechnical description
Safety thermostat intervention from dual sensor – excessive heating occuring due to any failure during normal operation, try resetting the boiler.
What causes this fault?
This fault occurs when the internal water temperature rises too rapidly or exceeds safe limits, 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 is more frequent during the first cold spell of autumn when pumps that have been idle all summer often seize up upon restarting.
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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