Nest learning has stopped turning boiler on when nest manually turned up for heating

[Cat222]

My UK learning nest has suddenly stopped turning on the boiler when I turn the thermostat on manually in the day.  However we are getting heating (most of the time, a few times not) when it's on its schedule am/pm.    

I have looked at other threads.  Do I need to get an engineer out to look at the boiler for either pressure switch or a possible sticking valve?  Of could it be something else to do with the nest itself?

thanks

[OannaCG]

Hey there! It might be a sticking valve from the symptoms you've mentioned. Could you please confirm what type of system you have? (is it a system boiler with a separate hot water tank?) Also, is it a Y plan wiring? 

[Cat222]

We have s plan wiring and separate tank and boiler. An engineer came yesterday and changed a valve and it seems to be working okay so far. Could there be any other explanation? 

[LarisaL]

Hi there, just checking. Did you see the message from above?

Thanks in advance, Larisa. 

[Paul_R]

Hi @Cat222! If the valve was changed and the system functions properly now, we'd assume that was the issue. Related to the thermostat, in cases like this sometimes it can be a stuck relay in the Heat Link, but in that case it doesn't activate the boiler at all anymore. Is there anything else I can assist you with at the moment?

[Cat222]

No thank you very much. 

[LarisaL]

Understood. In this case, I'll be locking this thread. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community. Have a lovely day ahead.