Wiring an Ecobee with White Rogers Zone Valve


  #1  
Old 11-30-22, 05:33 PM
F
Member
Thread Starter
Join Date: Nov 2022
Posts: 4
Received 0 Upvotes on 0 Posts
Wiring an Ecobee with White Rogers Zone Valve

I am trying to install a new ecobee Tstat (EB-STATE6-01) on a 1980's hot water heating system. It has an old White-Rogers type 125-202 Tstat. The Tstat has three wires (a forth is not connected).



I have traced the wires back to the zone valve which is a White Rogers Type 1311. The wires are connected as follows:


I spent some time on the phone with ecobee support and they said the system was in compatible with ecobee. I am not confident that the person I was working with was competent. I have searched this forum and have seen implementations with a two wire system like this, Installing Ecobee T-Stats with White Rodgers Zone Valves , but my system has three wires.

I have read other forums that suggest a relay is needed.

Does anyone have a wiring diagram for this type of a setup.

Thanks, FJ
 
  #2  
Old 12-16-22, 11:33 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 71,675
Received 3,332 Upvotes on 2,991 Posts
Apparently Ecobee has changed the connection method.
It used to be it would acknowledge either connection to R.
Now when using C you need to connect to Rc.

Good job and you're welcome.

 
fjaquish voted this post useful.
  #3  
Old 11-30-22, 06:49 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 71,675
Received 3,332 Upvotes on 2,991 Posts
Welcome to the forums.

I'm a little disappointed in Ecobee. The thermostat companies are so busy trying to better the other companies just offering a new product. They neglect to provide proper technical support. When I see that.... the thermostat goes on my do-not recommend list. Very unfortunate for a company like Ecobee.

Proper wiring diagrams should be.... no must be.... offered. A customer should not have to watch a video or download an app to install a product.

Does that thermostat come with an electronic control module that goes at the furnace ?
I need you to point me to the online info to that thermostat.
You will probably need a 24v relay too.
 
  #4  
Old 12-01-22, 05:02 AM
F
Member
Thread Starter
Join Date: Nov 2022
Posts: 4
Received 0 Upvotes on 0 Posts
PJmax, Thank you for your prompt reply.

Here is a link to the Ecobee Tstat that I purchased. https://www.ecobee.com/en-us/smart-t...ostat-premium/

Ecobee did spend about an hour on the phone with me but basically said to call a technician. Here is a call summary they sent back to me. "Based on the pictures you sent me you are likely not immediately compatible with ecobee.

This is because you have 2 wires that open and close the valve, whereas ecobee is only compatible with systems that only require 1 wire for opening and closing.

If you would still like to try to install the ecobee, you can try to use an isolation relay as a workaround for this issue.

I recommend doing this with a technician."

These are some links that suggested:


Helpful Resources:

ecobee thermostat installation with an isolation relay

My heat-only system only has two or three wires connected to the thermostat. Am I compatible with ecobee?

What types of HVAC systems are ecobee thermostats compatible with?

I wish I knew how the ecobee worked when it gets a heat call. From what I can tell from the old mercury WR Tstat it simply connected the Red (hot wire) from one terminal to the other, moving power from the #6 zone terminal to the #4 terminal when the Tstat called for heat. I don't know what kind of a signal the ecobee puts out on the Rc or Rh terminal. But could it be used to switch a relay that basically did that job?

Thanks, FJ
 
  #5  
Old 12-01-22, 12:01 PM
D
Member
Join Date: Jul 2022
Posts: 12
Upvotes: 0
Received 5 Upvotes on 5 Posts
Ecobee support is usually really helpful. But I think because your situation extends beyond a simple isolation relay they limit their advice. Anyways, I believe one half of a DPDT relay should suffice here (including pin #s on a standard 90340 relay):

W and C would go across the coil.
R would be common (pin #4)
6 NC (pin #5)
4 NO (pin #6)
 
  #6  
Old 12-01-22, 06:15 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 71,675
Received 3,332 Upvotes on 2,991 Posts
You can use any 24vac SPDT or DPDT relay. I use 90-293Q. One of several choices available.
Emerson relay

 
  #7  
Old 12-02-22, 09:39 AM
F
Member
Thread Starter
Join Date: Nov 2022
Posts: 4
Received 0 Upvotes on 0 Posts
Hi Pete, Thank you, I have ordered the 90-293Q relay.

Below is a drawing of my complete system (I think). I have read different posts on the Rc vs Rh, one would think I should connect to the Rh terminal, but I have read that only Rc works? My diagram shows it connected to Rc, if that doesn't work I will try the Rh.



Please let me know if you see something that does not look right.

Thank you, FJJ
 
  #8  
Old 12-02-22, 06:56 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 71,675
Received 3,332 Upvotes on 2,991 Posts
Your transformer diagram says "neutral leg."
Technically it's called common.
Other than that non-issue.... you're all set.

You should be able to use either R terminal. Ecobee checks both locations.
 
  #9  
Old 12-16-22, 04:47 AM
F
Member
Thread Starter
Join Date: Nov 2022
Posts: 4
Received 0 Upvotes on 0 Posts
Just to close this thread. I installed the Relay and the Ecobee is working as it should. The only odd thing is that I did try it with the Rh terminal and it did not work, using the Rc does.

A shout out to this Forum and Pjmax in particular. Thank you for the help that Ecobee was not able to provide.

FJJ
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: