I had initially the “ambition” to build my own transformer/relay in a box…
it turns out that both work and family activities forced me to look for a plug & play system.
I have ordered 5 units of this Aube RC840-240. Note those aren’t certified to operate in Europe… so you cannot supposedly buy them in Europe (have discussed with Aube themselves via emails and they refused selling me those).
So, I ended up buying those units from a 3rd party shop in California, they have arrived this last week end.
yesterday evening, at least to verify the concept would work, I plugged my current 2-wire “high voltage” thermostat thru this RC840-240 unit… and it works great. Picture and block diagram to come soon.
essentially, I am one step away from having my Nest wired to my heater a ELM Leblanc (natural gas) unit. Note the system I have actually selected could work as well on Electric heater systems with some cautious calculation.