topic Re: Need help with wiring. in Nest Thermostats

Need help with wiring.

itbob — Sat, 22 Oct 2022 03:51:46 GMT

I am installing a Nest thermostat. On the control panel I have RC and RH connected together, W, C and, G. At the thermostat I have G, Y, W and R. I have a heating and cooling system. I connected the wires to the same connectors on the new thermostat that was connected to the old thermostat (Y,G,R,W). It works most of the time but it gives me an N260 error. I bought a Nest Power Connector. In the instructions, it says to connect the power connector to the Y wire on from the control panel. I don't have a Y wire on the panel. So do I connect the control panel W wire to the W/Y on the power connector and R to the RC/RH connector leaving the jumper in place and of course, the C to C?

Re: Need help with wiring.

CoolingWizard — Sat, 22 Oct 2022 13:16:55 GMT

Since you have Y in use at the thermostat, that is your cooling wire. If look closely at the thermostat cable entering your heating air handler, you see two of them. One goes to the thermostat, the other goes to the outdoor condenser unit. The yellow from the thermostat cable it likely cross connected to the a conductor in the cable going to the outdoor unit. Is there a control board in your furnace?

Ken, The AC Cooling Wizard.

Re: Need help with wiring.

itbob — Sat, 22 Oct 2022 20:40:46 GMT

Yes, there is. Is there a way to upload a picture?

Re: Need help with wiring.

CoolingWizard — Sun, 23 Oct 2022 00:38:40 GMT

The way this community board works is as follows. You must upload the picture before you start typing text. Also, you email ID must be validated when it was sent to you. I hope this helps you.

Ken, The AC Cooling Wizard

Re: Need help with wiring.

itbob — Sun, 23 Oct 2022 04:17:55 GMT

Here is the control panel connections. The control panel

Re: Need help with wiring.

itbob — Sun, 23 Oct 2022 04:21:50 GMT

Here is the thermostat.

Nest cables

Re: Need help with wiring.

CoolingWizard — Sun, 23 Oct 2022 04:37:41 GMT

Let’s see if I can see this correctly.

Red wire going to Rh with a jumper to Rc

White wire going to W

Green wire going to G

Black or Brown wire going to C.

I do not see a Y terminal.

Did I get that correct ?

Re: Need help with wiring.

CoolingWizard — Sun, 23 Oct 2022 04:37:14 GMT

Ok, let’s see if get this correctly.
Red wire going to R

Green wire going to G

Light Blue wire going to Y

White wire going to W

No wire going to C. Is the black or brown wire there?

Re: Need help with wiring.

itbob — Sun, 23 Oct 2022 05:19:20 GMT

Yes. That's what has confused me. No Y.

Re: Need help with wiring.

itbob — Sun, 23 Oct 2022 05:37:57 GMT

You have that correct. I cut back some of the plastic and there is not another wire. And it seems that there are only 4 wires at the control panel.

Re: Need help with wiring.

CoolingWizard — Sun, 23 Oct 2022 17:21:55 GMT

Can see where the Light Blue wire at the thermostat on Y went at the furnace ? That is somehow cross connected to a cable going outside to the air conditioning condenser unit.

Ken, The AC Cooling Wizard

Re: Need help with wiring.

itbob — Sun, 23 Oct 2022 19:44:06 GMT

It is connected with a cap to a white wire that I think is going to the A/C.

Re: Need help with wiring.

CoolingWizard — Sun, 23 Oct 2022 23:56:13 GMT

Ok itbob, that sounds normal. The light blue is your Y terminal wire. And, there should be another wire going with the Light Blue/White going outside. It is inside the same cable sheath that the white wire is in.

Re: Need help with wiring.

itbob — Mon, 24 Oct 2022 00:17:13 GMT

Bundled with those two wires with the same cap? No, there isn't.

Re: Need help with wiring.

itbob — Mon, 24 Oct 2022 00:19:18 GMT

Blue and white wire.No other wire with the blue and white.

Re: Need help with wiring.

CoolingWizard — Mon, 24 Oct 2022 01:00:20 GMT

Itbob, in order for the AC to be turned on, there has to be two wires going outside. One is the primary 24VAC which is the White and Light Blue, the second would be the COMMON. When we use a two conductor cbale, there is usually a red and a white wire. Since the White wire would carry the 24VAC from the thermostat, the second wire would be the return COMMON.

Ken, The AC Cooling Wizard

Re: Need help with wiring.

itbob — Mon, 24 Oct 2022 03:07:35 GMT

The A/C does work but I keep getting an N260 error. It seems that the red wire from the thermostat is connected to RH which is jumpered to RC. There is a wire connected to C but it looks like it goes to the A/C.

Re: Need help with wiring.

CoolingWizard — Mon, 24 Oct 2022 15:59:37 GMT

In order for the AC to work, it needs the COMMON wire to feed back to the transformer. It is the same for the smart thermostats. The N260 error is the thermostat needing a COMMON wire path to the transformer. The red wire is indeed supplying power to the thermostat. If installing a new thermostat cable, with more conductor wires, is not an option, your other choice is to purchase and install a Google Nest Power Connector.

Ken, The AC Cooling Wizard

Re: Need help with wiring.

itbob — Mon, 24 Oct 2022 18:32:09 GMT

I did buy a Nest Power Connector. Since there isn't a Y wire on the control panel, where do I connect it? To the W wire?

Re: Need help with wiring.

CoolingWizard — Mon, 24 Oct 2022 22:44:31 GMT

On the Nest Power Connector, you will see it only connect to the Y or to the W, not both. Following the instructions that come with the nest power connector, you will disconnect the red wire from the furnace, that is coming from the thermostat, and connect it to the power connector. you will then disconnect the W wire from the terminal strip and connect that to the power connector on the same side that you connected the R, now take the group of three wires, take the R and connected to the R on the terminals drip in the furnace, take the seat connected to the sea in the thermal strip, and take the W and connected to the W on the terminal strip.

to get started, first make sure you turn off the power to the furnace. Then label and make the connections. Turn the power back on, go to the thermostat, and then go to settings power connector and then test power.

Ken, The Cooling Wizard