BoilerFaultCodesYour boiler's automatic routine to heat your solar hot water tank to a safe, bacteria-killing temperature has failed to complete.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Temperature for thermal disinfection not reached in solar cylinder: Delivery rate of disinfection pump (PE) too low or thermal disinfection cancelled manually.
What causes this fault?
This fault happens when the boiler attempts to run a safety cycle to kill bacteria in your solar water tank but cannot reach the required high temperature. The most common reasons are a faulty circulation pump that isn't moving enough water or a sensor that is failing to record the temperature increase correctly.
This issue may be more noticeable during winter months when lower ambient temperatures make it harder for the system to reach the high disinfection temperatures required.
DIY fix possible
Check if anyone manually cancelled the thermal disinfection cycle via the control panelEnsure there has not been a recent power cut that interrupted the heating timerPress the Reset button on the boiler to see if the code clears during the next scheduled cycle
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