topic Re: Power connector with Rele in Nest Thermostats

Power connector with Rele

AndreMonte — Mon, 04 Mar 2024 15:20:05 GMT

Hello Google Community!
I have a 2 wire system (R and W - heat only).
I am trying to add a Google Power Connector to my system which is set like this:
Thermostat > rele > valve
My rele is a 8 pin/port and is wired like this:

Here is the manual for the rele: https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/42586-source/003-dl-03

1 - 110V
2 - Load transformer
3 - Pump
4 -
5 -
6 - Boiler
7 - R coming from thermostat
8 - Boiler

W coming from thermostat + C Transformer

@David_K
@Ashepherdson
@CristianC
@rgaila
@MelbaDT
@Jhonleanmel
@thegios
@gilleslibre
@CoolingWizard

Re: Power connector with Rele

CoolingWizard — Mon, 04 Mar 2024 23:36:24 GMT

Your Nest power adaptor will need to be connected but first you need to find the wire going to R on the thermostat at the Heating system. Follow the wires from Pin2 and/or Pin7 and they will lead you to the 24VAC transformer. Your R wire going to your thermostat will be at the transformer. And, the power common will be going to the rele pin 2.

AC Cooling Wizard

Re: Power connector with Rele

AndreMonte — Fri, 15 Mar 2024 03:39:00 GMT

I am very sorry for saying this, but I am quite confused with your answer...
This is how my setup looks like:
If you can tell me how to change the wiring, I would appreciate very much!
Thank you in advance!!

Ps: if you need any other information, please let me know!

Re: Power connector with Rele

CoolingWizard — Fri, 15 Mar 2024 03:42:52 GMT

@AndreMonte , Let us see what we can figure out. The model 003 Rele has two states, the unenergized state and the energized state. In the unenergized state the 110VAC input on pin 1 is connected to pin 4 and the input wire connected to pin 8 is connected to Pin 5. In your case nothing is energized since pin 4 and 5 have nothing connected to them. When the relay is energized by supplying 24VAC Power to pin 2 and 24VAC Power Common to pin 7, then Pin 8 switches to Pin 6 and Pin 1 switches to Pin 3. Your Pin 3 sends 110VAC to the pump, and pin 8 connects to pin 8 coming from the boiler. This complete the connection on the boiler T and T which initiates the start up. There must be a 110VAC Neutral directly connected to the pump.

What you need to do is turn the power off, then at the thermostat move the red wire on W to the R and the orange wire from R to W. Now at the transformer swap the two wires, green to Common and red to R/Load.

After that turn the power on and check to make sure the system works. After that let me know and will help you get the Nest power connector installed.

The AC Cooling Wizard

Re: Power connector with Rele

AndreMonte — Fri, 15 Mar 2024 03:58:15 GMT

@CoolingWizard Before posting my question, my system was already working fine.
The only issue I need help with is to connect my Google Power Connector.
Ps: I did not change the wires. They still look exactly the same as show in the picture above.
I did not changed it because it works just fine. All I need is to connect the power connector to the system.
I really appreciate all your help into this!

Ps: I edited the picture just to add the neutral wire. After you mentioned on your comment I realized I did not draw the line from the 110 neutral to the pump.

Would you be able to help me with on how to connect the Power Connector?
Thank you!

Re: Power connector with Rele

CoolingWizard — Fri, 15 Mar 2024 21:54:04 GMT

@AndreMonte , in order to get the power connector and the thermostat to work and charge properly the power 24VAC load must be on the R terminal and currently your wiring has the 24 AC Power Common is on the R terminal. Making the changes I suggested would correct this. We cannot install the power connector until these charges this why I made the suggestion

AC Cooling Wizard

Re: Power connector with Rele

AndreMonte — Fri, 15 Mar 2024 22:58:37 GMT

Awesome I have made the changes you suggested!

How would I proceed with the power connector installation?

It would be something like this?

thank you very much!!!!!

Re: Power connector with Rele

CoolingWizard — Wed, 20 Mar 2024 06:48:20 GMT

Your bottom W goes to Pin 7.

AC Cooling Wizard

Re: Power connector with Rele

garayfedercio — Wed, 20 Mar 2024 20:57:19 GMT

Hi CoolingWizard, I just saw your posts and you are great solving problems. Can you help me with my post? Thank you!

topic Re: Power connector with Rele in Nest Thermostats

Power connector with Rele

1 - 110V2 - Load transformer3 - Pump4 - 5 - 6 - Boiler7 - R coming from thermostat8 - Boiler

W coming from thermostat + C Transformer@David_K@Ashepherdson@CristianC@rgaila@MelbaDT @Jhonleanmel @thegios @gilleslibre @CoolingWizard

Re: Power connector with Rele

Re: Power connector with Rele

Re: Power connector with Rele

Re: Power connector with Rele

Re: Power connector with Rele

Re: Power connector with Rele

Re: Power connector with Rele

Re: Power connector with Rele

1 - 110V
2 - Load transformer
3 - Pump
4 -
5 -
6 - Boiler
7 - R coming from thermostat
8 - Boiler

W coming from thermostat + C Transformer

@David_K
@Ashepherdson
@CristianC
@rgaila
@MelbaDT
@Jhonleanmel
@thegios
@gilleslibre
@CoolingWizard