Nest thermostat with Baxi caldaia murale – natural gas heater with Perri Termostati a 220 240v thermostat

edited on Feb 12th 2013 – futuristic views included

following a request from Massimo a Nest thermostat potential adopter in Italy,

I am trying to assist him in what could be the ad-hoc wiring of a Baxi gast heater mated to a Perri Termostati, a 220 240 thermostat.

the two thermostat wiring options are shown below:

perry thermostat TE120 TE121 TE122 TE123

elettronic termostati perry italia

in my opinion, the “red” boxed wiring (if compatible with the Baxi heating unit) is preferred.

Massimo having now confirmed his wiring is not the red box above, but rather the separate circuitry of supply and dry switch as shown below:

…I am starting to think about how is the actual wiring done at the heating unit level – my point being that I do not believe the actual wiring per Massimo’s feedback

is as shown below (from the Baci user manual):

section added on Feb 12th 2013.

so given the status reach previously, here is below what I would advise one may want to setup in order to make the Nest Thermostat work with a heating system not providing both line and neutral.

Please note that my preliminary conclusions are that the RC840T is not per-say compatible as-is.

baci thermostat nest wiring prosposed

Now if we want to get a notch more futuristic and ask Nest Lab a serious ease of implementation with “most” heating systems in EU (at least the ones working on 220 240 volts), here is what a good step forward would be….

I just want to point that this version of Nest thermostat does not appear to exist today, but it should not be that complicated to roll out for the European market.

what do you think? Do you concur?