UFH for MBC Passive

[graeme m]

Hello, Can someone point me in the right direction for the Jeremy's low pressure pump for the above?

[Jeremy Harris]

Mines a standard, off the shelf, Wunda manifold and low energy pump set.  They have changed the design slightly since I bought ours, but I've recently discovered that this doesn't matter.  The old design had a thermostatic mixer valve that would mix down to about 23 to 24 deg C, and would work well at around 25 deg C flow temperature.  I've recently fitted (at @Nickfromwales suggestion) a faster, motor driven, head what had been a thermal actuator valve that switches the UFH on and off.  This comes with two temperature sensors and in my case I've found that it holds a steady 5 to 6 deg temperature difference between flow and return, and that works so well that I now just have the thermostatic mixer would fully open, and don't actually need it.  The Wunda manifold and pump set I have is this one: http://www.wundafloorheating.co.uk/wp-content/uploads/2017/03/M02-Generic-Wunda-Standard-Pumpset.pdf   I'm using the Grundfos pump version, which seems to use very little power.

 

The motorised head that I have on the return valve (bottom right on the illustration above) that turns the UFH on and off (and now regulates the temperature) is the one described in this post by Nick:

 

[graeme m]

Thanks Jeremy.