three way electric mixing valve

[E_lexy]

Hi All,

I have a nicely functioning solar augmented radiant floor heating system.
Everything is working fine except for the regulation of in the floor temperature.
I have to manually change the setting on my three way mixing valve to compensate for outside fluctuations in temperature. I am sure this is not an issue that I alone have encountered. I Am looking for a solution to electronically regulate the floor temperature.

I have built the regulator with an Arduino clone: jeenode so I can handle analog or digital steppers. I just haven't been able to find anything yet.

Does anyone have any hints on brands / makes sold in Europe?

Alex