BoilerFaultCodesYour boiler is struggling to monitor the temperature of the water circulating in your radiators, which prevents the heating from working correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flashing lamp, alternate with another lamp.
What causes this fault?
This fault occurs when the internal sensor responsible for monitoring the heat of your radiators fails or provides an incorrect reading to the control board. Over time, these sensors can degrade due to constant temperature changes or suffer from internal electrical failure, meaning the boiler can no longer safely regulate the heat. In some cases, the issue may also be caused by loose or corroded wiring connections between the sensor and the main circuit board.
This fault is more frequent when the heating is first turned on after summer, as the sudden increase in workload can cause a weakened sensor to finally fail.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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