Underfloor heating?

[Hobo128]

I want to get an understanding of underfloor heating before installing it. Are the manifolds the same for combi boilers as for system boilers. The manifolds I have seen have a pump on them but I cant get my head around it, if installed with a combi and the ufh is calling for heat does that mean that both pumps start to run. Also do I need two two port valves installed, one on the radiator circuit and one on the ufh circuit

 

[SilentMike]

Yea I would zone it, you have full control then. 2 flows and common return
I would use dedicated pump for Ufh
You can get the design guide for about 18 pound

 

[macackau]

Both pumps will run if the UFH requires it. UFH runs at much lower temps than traditional central heating, typically 45-55 degrees. The pump on the manifold will push the water around the UFH pipes and the boiler pump will push water to the blending valve as required