On 14/02/2021 17:15, GP wrote:
Intermittent but usually happens at least once a day if heating is on.
Running hot tap generally sorts it. Its an EcoTech Plus. Just been
serviced and he replaced the PCB. Still happening. Any thoughts? ( Fan,
pump? )

Diversion valve perhaps - maybe "letting by" allowing the primary water
to partially circulate through the DHW circuit when the boiler is not in
DHW mode. Perhaps causing some vibration or "chatter". Opening the hot
tap causes the valve to open and close, possibly fixing it for a bit.


--
Cheers,

John.

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