evohome, megaflo and Vaillant ecoTech 637

[JWalker]

Hi All,
I'm planning an installation of evohome on my system to control both UFH and Hot water if possible.

My current config includes a Vaillant ecoTech 637 that is already connected and wired to a megaflow 250i providing hot water on demand as expected.
The heating works fine as soon as I open the motorised valve of the heating circuit firing the boiler. Ideally I would like to control the UFH with the ATP921R3100 via HCC80R and ideally to check and control the hot water temperature in the Megaflo through ATF500DHW.

is this possible?

[Richard]

Yes this is possible but would only control as a ErP Class 4 system, unless you use the VR33 which Vaillant UK don't like.