BoilerFaultCodesYour heat pump’s automatic high-temperature disinfection cycle for your hot water tank failed to complete as scheduled.
This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.
Technical description: Anti-Legionella does not Operate
What causes this fault?
This fault occurs when the system is unable to heat the water in your cylinder to the high temperature required to kill bacteria within the set timeframe. The most common reason is a failed immersion heater element or a faulty sensor that is incorrectly reporting the water temperature. It can also be triggered if the immersion heater has been manually turned off at the isolating switch, preventing the disinfection cycle from starting.
DIY fix possible
Check that your hot water cylinder immersion heater switch is turned on and hadn't tripped.Ensure hot water schedule allows enough time for the tank to reach 60-65°C.Restart the heat pump control panel to clear the temporary warning.
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