Huge difference between set and actual room temperature

[iMCaan]

We have water UFH on ground and first floor and both floors are screeded. 

 

In one of the ground floor rooms, the temperature rises to as high as 23 degrees with Salus thermostat set at 8 degrees (same as the other rooms) that's a huge 15 degree difference. In the other rooms the temperature is mostly around 10 degrees.

 

I've taken the room temperature manually and it matches the temperature displayed on the Salus thermostat so it doesn't appear that thermostat is not faulty nor is the Salus auto actuator, which comes on and goes off. 

 

So what could be the reason?

Why would there be such a high difference between the set temperature and the actual room temperature?

 

Thanks

[ProDave]

post the details of the exact thermostat.

[JohnMo]

I would check the thermostat settings and your controller.

 

If rooms are 10 degs and you have the thermostat set at 8 degs, where is your boiler call for heat coming from. More details needed

 

 

[iMCaan]

It's Salus  Quantum 230v Programmable Thermostat and Salus CB500 5 Zone wiring centre.

 

@JohnMo I need to think about this. How it works?

 

 

[JohnMo]

Which quantum model? There is one for UFH and one for radiators.

 

Do you have self learning stopping starting on or off?

[SteamyTea]

35 minutes ago, JohnMo said:

quantum model

The Copenhagen model allows for it to be both on and off, simultaneously.

The room temperature will only be revealed when it is measured. 

[Nickfromwales]

Ffs. 
 

I googled ‘model’ and ended up back here….. 

[JohnMo]

15 minutes ago, Nickfromwales said:

Ffs. 
 

I googled ‘model’ and ended up back here….. 

Two basic models, WQ610 is for radiators and SQ610 for UFH.

 

If you have a WQ on UFH and you have any self learning functions active, the thermostat loses all control as the algorithm is wrong for the application. A WQ will work with UFH, but only if you use in a simple on off mode.

 

Been there, done it, got the tee shirt.

[Nickfromwales]

15 minutes ago, Nickfromwales said:

Ffs. 
 

I googled ‘model’ and ended up back here….. 

👆

2 minutes ago, JohnMo said:

loses all control

@SimonD gets what I was looking to achieve.