Heating not working

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Working from home yesterday - radiator had been working in morning, then room/house went noticeably cold in afternoon. Went into the app and it told me that the heating was not responding as expected. No Open windows etc.

I have replaced both Zone valve actuators (1 Central Heating & 1 Hot Water)

I can get the heating to fire and heat if I manually set the Zone valves, but they do not actuate by themselves

I have reset the bridge and switched off/on the Tado thermostat and Extension kit.

I have set the rooms to Boost in the app (the app keeps turning this off)

I have set the hot water to on in the app.


anyone got any next steps ???