i'll just throw this out there on the power wire thing - they can be powered off a doorbell transformer, or a wall bug (25vac) if needed. just fish another
two wire cable, and hook one to the common, and one to the white(or red, depending) - one transformer can not up the voltage of another unless linked in series
(which makes one larger transformer) - that would then produce a missing wire.
Aaaand of course you anticipated my next move....
So I have a 2 zone system, heat only, and looking to just control the main zone via smart t-stat.
Existing connection is 2 wires, and reading up on the aquastat on the boiler,
there's no easy way to connect a C wire. (If you want to geek on it:
Honeywell L8124A, C)
I would have to remove the circuit board, and solder a connection to the back of it.
No way am I going to mess with that.
As I was getting despondent over possible options,
I came across this from the folks over at Emerson for hacking a plug in transformer for their Sensei:
https://sensi.emerson.com/en-us/support/adding-a-24-vac-external-transformer
This is perfect, because that was the model I had settled on- cheap, and it does everything I need.
So, not ecstatic about not being able to hardwire this jammy,
but I can live with a secure plug somewhere.
I'll have to see my options.
My question: is there any limitation to extending the cord from the transformer?
For example, I could use the existing wires to fish through a new run of 18/4, 5 or 6,
replacing the existing R/W and use 2 wires from the new cabling to connect to the adapter in the crawlspace near the boiler.
If it matters, the run would likely be in the neighborhood of 20-25'.
What say ye
@fidodie?