UFH Pump - Always on?

[Chalked]

Best to disconnect the nest from the ufh. It can’t anticipate the heat and cooling demands.

 

[Jones82]

I think the nest has an underfloor heating setting? It certainly has a "radiator" option. I think the trouble here is the pump has a permanent live, likely from a crossed wire with the grey on the 2 port valve... assuming there is one!

Does the pump run even when the boilers off?

 

[Brambles]

Nest works with both electric and wet underfloor heating systems. The latter must be properly designed and well balanced to deliver a consistent and even heat pattern to give Nest a chance to work effectively.

The normal issue ( problem) is that the Nest Heatlinks for multiple zones are placed too close together and too close to “significant” metallic objects - multiple copper pipes or hot water storage tanks. Heatlinks should be spaced at least 300mm apart, preferably a lot more. To be fair this is an issue ( signal interference) with the Honeywell wireless systems too

 

[MJB5373]

Hi Jones, the pump shows the green light always, and makes a very low sound, which is mirrored through the pipes. So I’m assuming it’s doing something... even when the boiler isn’t being called.

I think the nest has an underfloor heating setting? It certainly has a "radiator" option. I think the trouble here is the pump has a permanent live, likely from a crossed wire with the grey on the 2 port valve... assuming there is one!

Does the pump run even when the boilers off?

 

[Brambles]

Yes, it is. Probably circulating cold water 24 hours / day.

Generally, Wet Under Floor Heating Systems are silent to the human ear - well they are to mine anyway!!

 

[Jones82]

The pump live needs connecting into the switched live for the underfloor heating zone, usually the white cable on the 2 port valve that controls the underfloor heating zone.

 

[Uheat – Jake]

As Jones says, just a simple wiring issue. The pump will have a permanent live to it when it only needs a switch live which will become live when your nest thermostat is calling for heat.