Can’t switch heating of

[Laura-Emma]

We’ve controlled our heating without any issue for 5 years using Nest thermostat. 
Not changed any settings. 
This week heating is coming on full blast throughput the day and night even when Nest heating mode is off. Usage on app says no usage even though there has been hours of it. 
Have pressed restart but not helped. 

[Laura-Emma]

No heat is scheduled and the true radiant is off 

[Patrick_Caezza]

Which Nest thermostat do you have, and how is it wired?

What happens if you remove the thermostat from its base while it is happening?

[Laura-Emma]

@Patrick_Caezza 

  thank you for your reply. It’s attached to the wall! It was here when we moved in 5 years ago so I’m not sure of the exact make 

[Patrick_Caezza]

@Laura-Emma 

Unfortunately, you have a Heat Link, which I know nothing about.

Sorry, but I can't help you.

[TudorL]

Hi there, have you managed to check the last message from my colleague? 

[AlexD]

Thanks for reaching out here @Laura-Emma. I would be happy to try and assist. 

Just to confirm, does the thermostat control both the heating and the hot water, so a system boiler with a separate hot water tank at the location, or is it just the heating?

Thanks for offering to help @Patrick_Caezza, always appreciated, no worries.

[OannaCG]

Hey there, since we haven't heard from you for a couple of days, we'll close this thread for now. If you still need help, let us know so we can continue. Thanks!