Baxi system boiler and Opentherm

[Harp62]

Thanks to @Ian777 - I've just ordered EPH Combipack 4, a separate cp4i for a 2nd heating valve and the cp4-hw-ot for cylinder stat based on your post for my new Baxi 830 system 2 which is now officiallyopentherm certified. I've looked into all the other controllers on the market that support opentherm but only the EPH controls support opentherm plus 2 heating zones and a hw cylinder on a system boiler