Yet another nest/ecobee question

LeSer

Yet another how to wire up nest/ecobee question. Basically both nest and ecobee doesn't power on. Nest is 3, i took from my house to tried out. Ecobee 4 is new, got it onsale during BF. This was a house converted from oil to gas. Was on nest 2, nest 2 worked with the R & W wiring. But after conversion, it doesn't work anymore. Any tips ? Thanks..

The boiler is weil mclain peg/eg-50. First pic is existing wiring to simple thermostat , just R & W.
R at thermostat goes to Y in the schematics
W at thermostat goes to W in the schematics
C goes to C in diagram - I added.

ratio

Are you sure about the 'W' terminal? The schematic show the stat going between the 'Y' and the 'G' terminal.

LeSer

Yup.. that block is upside down and Y goes to the red wire.. dunno why, it was setup that way..

LeSer

I should say the schematic and what was actually hook up doesn't make sense right..

ratio

Do you have a meter to check voltages with? I can speculate, but without verification you run the risk of damaging something.

LeSer

I will borrow one tomorrow. Where should I take voltage off. Thanks !

HVACNUT

Thermostat connections at the boiler to Y and G, to R and W at the thermostat.
Common (C) at the boiler connects to C on the thermostat. You NEED that C connection. I see a green wire there behind the thermostat sub base, so use that and you should be good.

LeSer

I already tried the C to C and it doesn't work on existing wiring.

But I will do Y-R and W-G, instead of W-W (currently) and C to C.

I really dont know why W goes to W even though the schematics shows it shouldn't be hook up that way.

Now im curious why its working on dumb thermostat, unless the existing wiring is somehow wrong

BoilOver2

@LeSer

Can you posted a picture of your ecobee wiring plate with what you've tried?

Probably not the issue, but you have to hook up something to rc on the ecobee (at least the 3 model), even though on a two wire setup rh seems like the logical choice.

That bit me over the weekend.

Jamie Hall

It works on a dumb thermostat because the dumb thermostat is simply a switch, nothing more. What you are looking for is the wiring combination which will properly power the Ecobee, which requires constant 24 VAC power, and which -- with a third wire -- will behave like a simple switch.

I have to admit that I find the wiring diagrams which Ecobee supplies are... strange. And, honestly, I'd have to have one in hand to figure out which terminal on the Ecobee did what.

LeSer

I dont have any now.. I have a separate 24v adapter coming just in case I dont get it from the boiler. If i dont use it here, nest doorbell can use it.. just fyi ecobee 4 in my house R/R W/W C/C no issue.. I have the weils cga and labels are pretty clear. Thie weils peg/eg50 has slightly different setup.. Might not get testing done tonight, Xmas party at work... probably get home late.


I had tested the cable in RC at one point, I went through the manual, they had mention that.. move from rh into rc

LeSer

Got it working. Original wiring R to Y, W to W
I added the 24v to rh and rc.

I tried the RY and WG like schematic - did not work. Wonder if they fk up wiring behind label