Nest Thermostat & Worcester 8000 Life Boiler

[Muj]

Hi everyone,

After some advice,

I’ve recently had a new central heating system and boiler in my house. I’ve had the Nest thermostat 3rd Gen put in with Danfoss Ras-C2 TRV and lock-shields. The system hasn’t been balanced.

The thermostat is switching the boiler on and the rads are getting hot. However, if I set to 20° for example, the thermostat will never reach that (which is fine as I’m guessing the house isn’t heating to that ambient temperature) but if I leave the heating on for 2 hours the radiators start cooling down but the Nest still shows heating and the boiler is still firing.

I’m confused as to what is going on, can someone please give me the correct guidance?

Thank you,

 

[ianmcd]

The radiators will start to cool down depending what the TRVs are set to and what the AIR temp is in that room, the nest will only control the temp in the room where it is situated and the rad has no TRV fitted

 

[Muj]

Ahh I had a feeling that’s the case,

my thermostat is in the hallway which reads 17°c at best but the bedrooms get warmer, so the rooms are getting hotter than the hallway and switching the rads off I guess?

 

[ianmcd]

Ahh I had a feeling that’s the case,

my thermostat is in the hallway which reads 17°c at best but the bedrooms get warmer, so the rooms are getting hotter than the hallway and switching the rads off I guess?

yes the TRVs are controlling the rads in the other rooms

 

[Muj]

Thank you,

I’ve got my TRV on the highest setting, do you know at what temp they cause the rads to cool down?

 

[ianmcd]

Thank you,

I’ve got my TRV on the highest setting, do you know at what temp they cause the rads to cool down?

No you will have to look up the literature for the TRV you have, an easy test is remove the plastic sensor , easy job no tools needed and see if the rad stays hot then, if it does it is indeed the sensor that is closing the rad down, post a pic of the TRV and we will tell you how to take the sensor off

 

[Muj]

Ok will do,

I have this one:

https://www.screwfix.com/p/danfoss-...u-FNXgS0yKjC9-PPoyhoCKYgQAvD_BwE&gclsrc=aw.ds

 

[ianmcd]

OK set the TRV to max and hold the white part with one hand and screw the grey ring Anti-clockwise, untill it stops just a few turns then gently pull the sensor off , refitting is just the reverse, always do it with the valve set to max