The need / benefit for blending valve in this pic?

[wodger]

Hi,

Wondering if anyone can explain the benefit of a blending valve in this pic?

This is the system is for the under floor heating in my conservatory.

The pipes dissappearing up through the roof come out the top of the conservatory into some pipe insulation and then seem to enter the house at about floor level in one of my bedrooms upstairs. Quite suprised when I saw this... is that common practice \ acceptable.

There is no dedicated connection to the boiler from these pipes so I can only assume they are plumbed into my central heating. Again, is this common practice and would it have any impact on me changing my gravity fed system for a fully pumped version next year?

Thanks
Warren

 

[clf-gas]

Its there to reduce the temp as under floor is run at a lower temp than a convetional wet rad system.

 

[Gasguru]

Stops you burning your toes on the floor...otherwise it would reach the boiler maximum temperature perhaps 80 to 90 centigrade.

It wouldn't do the floor a lot of good either, and you could roast the dog.

 

[wodger]

Ahhh... thanks for that. Makes sense.

So I guess it works by restricting the flow and allowing some of the return out the bottom of the valve?

Any chance this would cause a problem with me having a pumped system installed? I guess it would as if CH valve is not open then how will conservatory get heat?

 

[ChrisR]

if CH valve is not open then how will conservatory get heat?

It won't. You need to T the UFH off before the CH zone valve.

The way they usually work is that the UFH pump circulates water at a temp set by the mixing valve, which gets a bit more hot from the CH pipe when the water cools down.
Look up a few UFH company sites - they'll explain it better.

 

[wodger]

Second of the day.

Thanks Chris.

 

[clf-gas]

Heres the suppliers of your manifold http://www.freeyourwalls.com/content.php?section_id=1&content_type_id=12


Have a route round there


Ps, Merry christmas/happy new year