BoilerFaultCodesWhat the manual says
Manufacturer manualTemperature supply sensor too high (> 101 °C).
What causes this fault?
This fault occurs because the water leaving the boiler has exceeded a safe temperature limit, causing the system to shut down for safety. It is usually caused by a lack of water flow, often due to a pump failure or a blockage within the heat exchanger that prevents heat from being carried away quickly enough. In some cases, the sensor itself may simply be faulty and providing an incorrect high-temperature reading.
This issue is more frequent during the first cold spell of autumn, when pumps that have sat idle all summer can 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.
Avoid the next call-out bill
A cover plan would handle faults like 4A: no call-out fees, no surprise bills.
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