BoilerFaultCodesTechnical description
Domestic hot water (DHW) sensor overheating error
What causes this fault?
This fault occurs when the internal sensors detect that the water temperature has risen beyond a safe limit, triggering a shutdown to prevent scalding or component damage. The most common reason is a faulty temperature sensor sending incorrect readings, or a build-up of limescale inside the heat exchanger which prevents water from flowing and cooling down properly.
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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