Do I need a CH pump with a new combi boiler?

[jks]

Just about to buy a new combi boiler (probably Glow-Worm 38) and also want to convert the whole house to under floor heating.

I was under the impression that most new combi's have an internal central heating pump and so another is not needed if connecting to a conventional radiator system.

My question is......so is that still true with under floor heating?? Will I need another pump to push the water round in addtion to the combi one?

Also, are there any other bits of kit that need to sit between the combi CH flow and return and the UFH manifold? I was kind of hoping that by turning the temperature control of the central heating on the combi to a very low setting would be all I need to get the temperature right for the UFH manifold..

Before anyone asks, I am going to get a plumber to assist me on this, I am just trying to get it straight in my head before I start!!

Thanks in advance for your help.

Stuart

[Doctor Drivel]

Form a loop from the combi using the combi pump. Then another pump circulates around the UFH pipes from the manifold usually using a blending valve to maintain the low temperatures. If only UFH off the combi then set the combi to a low temperature, just above the settings to the UFH zones set by the manifold blender.

[Doctor Drivel]

The combi will have two separate temperature controls for CH and DHW. The DHW water does not enter the CH circuit.

In theory you can have UFH off one pump, but you are then making an inefficient system.