Blending valve needed for UFH manifold with Ecodan pre plumbed set up?

[jfb]

I remember reading elsewhere that a blending valve is needed (best practise) for the UFH manifold in an ASHP setup (might have been you saying it Peter!)

 

My set up is Ecodan PUZ-WM 6kw ASHP, pre-plumbed cylinder with FTC6 controller.

UFH heating in one zone downstairs and large rads upstairs as a second zone. No buffer tank, low loss header included on the cylinder.

 

I bought an UFH package that includes a blending valve for the manifold.

My plumber started work today on the install and he said that no blending valve is needed as the pre plumbed cylinder does all the modulating down to the desired temperature.

 

Is he right?

 

 

 

Edited September 15, 2022 by jfb

[ProDave]

I would insist your plumber fits the blending valve.  Your radiator circuit will almost certainly want a higher temperature than the UFH and there is no way the ASHP even with it's tank can produce 2 feeds at the same time at different temperatures.

[jfb]

14 minutes ago, ProDave said:

Your radiator circuit will almost certainly want a higher temperature than the UFH and there is no way the ASHP even with it's tank can produce 2 feeds at the same time at different temperatures.

I can see the logic of this, thanks

I had originally been hoping to do without rads upstairs as it should be well insulated/airtight but went with them to conform to spec needed for any hope of getting the grant available. I had been thinking that I might get away with just one temperature for UFH and rads as well (they are oversized) but maybe I am delusional about that!

 

I'll speak with plumber and see what he has to say.

[JohnMo]

Our UFH flow temp is around 27, not sure if huge rads would like that low a temperature.