Need Help! - 2 Wire Boiler with 3 Zone Valves - WIFI INSTALLATION

jeveritt54

Hi,

I am really hoping someone can help me. I have had zero luck trying to install wifi thermostats at my house. I am trying to install 3 Ecobee 3 lite's. I have a 2 wire boiler, heat only, and 3 zone valves. I have attached a drawing of how my system was wired with battery 2 wire thermostats, which worked fine. After numerous discussions with Ecobee I ran new 18/5 wire so I could have 4 wires at the thermostat for power for the Ecobee. I have also attached a drawing of how I thought it should be based off of what Ecobee is telling me. Long story short, I cannot get this to work. The Ecobee powers up fine, sends a heat signal, but the boiler is not kicking on, or not getting a signal to turn on. I'm sure its somewhere in the wiring, but I can't figure it out and Ecobee hasn't been helpful at all.

Please help!

Ironman

Can you post some pics of the zone valves and wiring?

This may be your best solution:
https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Taco-ZVC404-4-Brochure.pdf

jeveritt54

Added a picture of the zone valves. There is also 2 other pictures, 1 working, the other doesn't work with new thermostats.

STEVEusaPA

They seem to recommend an isolation relay for your installation.
A Taco 4 zone panel would make this much easier.
When the thermostat calls for heat, do you get 24V from Rh, and when it's not, no voltage from Rh?
Seems like 24v goes into Rc, does it come out of W or Rh when the tstat calls for heat?
Despite the drawing, and it's not my thermostat to fry, I would put Rc from transformer, W to terminal 1 in the zone valve, C from tstat back to transformer. And terminals 2 & 3 on the zone valve, T-T on the aquastat, and C on the transformer like your first drawing.
Edit: If no one pops on to correct me, I would try one thermostat first, make sure it's working, then the others.

jeveritt54

Attached is what Ecobee sent me or recommends. Supposedly if you take RH and W and wrap them or wire nut them it should manually work. So I am assuming it comes out of RH and back on W, but I am not sure.

Jamie Hall

Thinking "in" and "out" may be your problem. Think instead of the thermostat as being a switch. If it is turned on -- the switch is closed -- it connects W to either Rh (if heat is wanted) or Rc (if it's cooling you're after). It doesn't matter which way the current flows through the switch -- in fact, it flows both ways, since it's AC -- but it does matter that if you want heat, you want power to flow from your transformer through the heat switch to the zone valve and back to your transformer.

Ironman

"TT" on the boiler is looking for a set of dry contacts to go through, not have 24V applied to it.

You need the Taco ZVC panel. It's made specifically for these scenarios.

Jamie Hall

and to clarify for the OP -- "dry contact" means no voltage applied to either terminal. Just a plain vanilla switch -- which is what the old thermostats were.

jeveritt54

Thank you for all the responses. I just ordered the ZVC Panel. Will update when I install it.

jeveritt54

Hi, everyone. I installed the ZVC Panel on Friday after work. It was very simple to hook up. It worked like a charm. Thank you for all the help. I appreciate it!