topic Re: 2 Red from 2 separate system Mirror Nest in Nest Thermostats

2 Red from 2 separate system Mirror Nest

ronaldjj80 — Fri, 18 Nov 2022 14:31:32 GMT

I have a Nest (the mirror) thermostat. I have separate heating (Rh, W) and air (G, Rc, Y, C).

There's only 1 R on the nest thermostat. How should i proceed? Someone said that I can tie both R coming from the separate systems together and then pigtail it into the thermostat.

Is this a viable solution? thanks

Re: 2 Red from 2 separate system Mirror Nest

Markjosephp — Tue, 22 Nov 2022 20:28:32 GMT

Hello ronaldjj80,

Thank you for reaching out and letting us know about your inquiry. I'd love to help.

Some HVAC systems, called dual transformer systems, use separate power sources for heating and cooling (Rc and Rh). If you have both an RH and an RC wire, you have a dual transformer system, which would work for Nest Learning Thermostats. Check out this guide for Nest Thermostat compatibility and let us know if you have more questions in mind.

Best regards,

Mark

Re: 2 Red from 2 separate system Mirror Nest

ronaldjj80 — Tue, 22 Nov 2022 21:00:42 GMT

Thanks for the heads up. I was able to get everything connected. But now the rh "power" is grayed out on the wire configuration. This is strange because when I direct connect the W and Rh wires my heat comes on without issue.

Re: 2 Red from 2 separate system Mirror Nest

Markjosephp — Tue, 22 Nov 2022 21:38:09 GMT

Hey there,

Thanks for letting me know. Let's sort this out.

A few questions: do you see any wiring reports or message codes? Could you send us a picture of your thermostat's wiring setup? Also, please check the power status under the technical information settings.

I'll look forward to your response.

BEst regards,

Mark

Re: 2 Red from 2 separate system Mirror Nest

Markjosephp — Fri, 25 Nov 2022 21:54:48 GMT

Hi ronaldjj80,

I'm checking in to make sure that you've seen my response. Please let us know if you have any other questions or concerns.

Thanks,

Mark

Re: 2 Red from 2 separate system Mirror Nest

ronaldjj80 — Fri, 25 Nov 2022 22:54:13 GMT

Hi Mark

Yes thanks for the response. I was able to get the nest learning stat. I have another challenge. I also have the 1 system stat(mirror version) on a 2 wire heat system. There is no C connection so I purchased the 24v power supply but with only 1 R terminal ok the backplate how should I connect the power supply? One goes to the C terminal on the backplate bit how would the other wire go?

Re: 2 Red from 2 separate system Mirror Nest

Markjosephp — Sat, 26 Nov 2022 21:51:17 GMT

Hi there,

Thanks for getting back to us. Let's see what we can do.

Installing it by inserting the power wires into the R terminal might help, but it's not an ideal way for configuration as it might damage the internal breakers of the base. I'd suggest that it would be better to install a Nest Power Connector.

Here are some references to help you install your Nest Power Connector on your HVAC system.

Feel free to let us know if you have more questions.

Thanks,

Mark

Re: 2 Red from 2 separate system Mirror Nest

Markjosephp — Wed, 30 Nov 2022 13:18:42 GMT

Hello ronaldjj80,

I wanted to see if you still needed help. Please let us know if you have any other questions or concerns.

Best regards,

Mark

Re: 2 Red from 2 separate system Mirror Nest

Markjosephp — Thu, 01 Dec 2022 14:49:05 GMT

Hi ronaldjj80,

I'm just checking in to make sure that you've seen my response. Please let us know if you have any additional questions or concerns before I close this thread in 24 hours.

Thanks,

Mark