Hi-Lo heating thermostat for UFH

[gravelrash]

I am on first fix and UFH installation. I am running system as single zone with slab sensor at around 20c, I also want to distribute water around the circuit during summer as I have high solar gain from windows. Does anyone know of a thermostat that has high low temp settings/switching and 2 controller wire connections so it can switch pump on at high temperature without switching boiler on... Something like an american style heat/aircon thermostat maybe. 

[ProDave]

I can't help directly but I believe it is called a "heat - cool thermostat"

[JohnMo]

Would you need to add a zone valve or manual valves also and effectively circulate through a loop that does not involve the boiler.

 

You need your underfloor heating pump to start, but you also need a loop forming that is upstream of the UFH tcv.  This will allow the discharge side the the UFH manifold to flow somewhere and give an inlet flow through the tcv and pump.  Without this your system will not move water about the circuits.

[PeterW]

A Shelly could do it easily with a temperature add on. You can do the if/then logic also. 

[Temp]

Looks like some Nest can do that..

 

https://www.howtogeek.com/252539/how-to-switch-your-nest-thermostat-from-heating-to-cooling-and-vice-versa/#:~:text=Press on your Nest Thermostat,would in the Nest app.

[gravelrash]

7 hours ago, Temp said:

Looks like some Nest can do that..

 

https://www.howtogeek.com/252539/how-to-switch-your-nest-thermostat-from-heating-to-cooling-and-vice-versa/#:~:text=Press on your Nest Thermostat,would in the Nest app.

But the nest does not support sensor connection

[Temp]

Sorry I missed the bit about the floor sensor.

 

It seems Nest do have a remote sensor unit but it's a self contained wireless sensor intended for other rooms. Most stats i've seen use a 10k NTC Resistor for the actual sensor so might be hackable to take a remote floor sensor instead. I added my own remote sensor to a Heatmiser stat.

Edited April 8, 2022 by Temp