System boiler - OpenTherm
Hi - hoping to shed some light on the functionality between a System boiler and Tado. I've read some info here, on the Tado site - and also contacted support (..and still could have some details incorrect). Are we safe to assume that Combi boilers are able to connect to Tado through OpenTherm, and that System boilers communicate through a more more rudimental method using 'call for heat' (using a 'duel relay', I'm not quite clear on this, maybe the same thing?)?
I'm looking for an optimum setup to use with a new System boiler and megaflo (heating ~15 radiators and two showers) which I'm hoping this post will help me source. So OpenTherm appears to an obvs choice, if it was compatible. From contacting Tado support who now appear somewhat cold I was told "We only support Opentherm connections via Combi boilers. Normally in the typical UK heating systems we support only dual relay connections and tado° acts as a standard programmer." which all appears pretty clear language.
However as I understand System boiler manufactures have their own Smart Thermostats, and Tado is able to connect using the manufactures language. So are there certain System boilers which have more advanced features similar to Opentherm (or even using Opentherm?)? Or are System Boilers just limited to call-for-heat and I should just go out and buy an efficient one compatible with Tado?
Finally, is Opentherm just the ability to modulate heat efficiently? Or does it involve further some other Tado functionality, such as taking in weather.
Thanks for reading, and answering!