The Aube rc840t-120 may not be suitable for the amp draw of the motor. https://customer.honeywell.com/resources/Techlit/TechLitDocuments/69-0000s/69-2562EF.pdf
I would use these knock out mounted devices.
Also, did you consider useing off/on switches instead of micro switchs at each port...
The HydroStat looks like it should work, supplyhouse.com is cheaper then Amazon.
https://www.supplyhouse.com/Hydrolevel-48-3200-Model-3200-Fuel-Smart-Hydrostat-Temperature-Limit-LWCO-Boiler-Reset-Control-for-Gas-Boilers
1- RIBU2C relay / https://www.functionaldevices.com/products/building-automation/details/RIBU2C/
1 - transformer 120 to 24 volt
You may be able to control both heaters with a smart tstat like the Ecobee, it's a 2 stage tstat.
For your heater I would connect the N.O. contacts of the relay to the L1 leg between the power light and the tstat. Also, set the heater tstat 5 to 10 degrees above the wall mounted tstat.
Yes you can get the 115 volts from any source that's always on. The fan center mounts onto the 4x4 box...
Yes you could use 2 relays, I would not wire it that way. But as far as using the G terminal on the tstat. It is not energized in the heating mode. It gets powered thru the Y terminal or the fan auto/on switch.
Yes you could use a dial or digital tstat. The OP wants to connect a smart tstat to have the ability to operate the heater from inside of his house.
The transformer for the setup I described is for the control circuit. Its 115 volt primary to a 24 volt secondary. It will power the relay and...
The way I would go about installing a remote tstat for this heater is as follows.
1-Get a fan control center that will handle the amp draw for the fan and a 4x4 electrical box.
2-Run a 115 volts to the 4x4 box to power the transformer.
3-Run 2 wires from the 4x4 box to the heater. Connect the...