topic Re: Lux 1500 to Nest in Nest Thermostats

Lux 1500 to Nest

georgep — Sat, 18 Nov 2023 16:23:58 GMT

I have a duel zone system. I already have a nest on the subordinate zone. I am trying to replace an older Lux 1500 with the Nest on the main zone - it does not recognize it.

The system is a force air Oil with AC.

Wires connected on the Lux are G Y W RH jumper to RC B and O - any help would be appreciated. thanks

Re: Lux 1500 to Nest

georgep — Sun, 19 Nov 2023 01:35:57 GMT

Re: Lux 1500 to Nest

georgep — Sun, 19 Nov 2023 14:20:33 GMT

I cant seem to post to a prior question so I had to start a new one, sorry for any confusion.

Attached are better picks of the wiring.

Re: Lux 1500 to Nest

zoeuvre — Thu, 23 Nov 2023 17:41:34 GMT

Hi georgep,

Thanks for posting, and I'm sorry to hear that your thermostat does not recognize your thermostat wires. Could you send us a photo of how you wired the thermostat wires to your Nest Thermostat? Also, make sure that the wires are firmly seated on each of the Nest terminals and that the power to your thermostat is on.

I'll look forward to your response.

Best,

Zoe

Re: Lux 1500 to Nest

georgep — Sat, 25 Nov 2023 14:30:23 GMT

Thank you for the response, attached is a photo of how I tried to wire it, I left off the heat pump as I do not think my unit has one. When I connect the Nest to this wiring configuration I hear clicking sounds, so I removed it at once. I can not post a picture as it says I now do not have permission to upload images.

But I wired, Yellow to Y1 Green to G Red to R

White to W Blue to C

thanks,

Any suggestions?

Re: Lux 1500 to Nest

georgep — Sat, 25 Nov 2023 14:30:55 GMT

Re: Lux 1500 to Nest

zoeuvre — Sat, 25 Nov 2023 21:42:07 GMT

Hi there,

Gotcha. I checked your thermostat wires and I can confirm you installed them correctly. If your thermostat isn’t detecting a wire, or there’s a power issue, you should check that the wire end is straight, fully inserted into the wire connector, and isn't corroded. Follow the steps here in the Thermostat wire undetected or unconfigured guide to troubleshoot.

Let us know how it goes.

Best,

Zoe

Re: Lux 1500 to Nest

georgep — Sun, 26 Nov 2023 00:46:25 GMT

Hi and thank you for the response, I checked the wires and they seem to be solidly connected. Could I be wrong in my assumption that the blue wire goes to C and not B/O?

thanks

Re: Lux 1500 to Nest

Jenelyn_O — Tue, 28 Nov 2023 22:56:08 GMT

Hi everyone,

Chiming in — I'd like to check it further. In what country are you located? We need to identify if the wire is the one not delivering sufficient power to your Nest Thermostat, or the thermostat itself is the one not accepting the power from your wire. Do you have a voltmeter? If yes, are you comfortable using it?

Voltmeters and multimeters come in two types, analog and digital.

Analog models are no longer common, but they can still be found. They have a needle that moves across a window similar to a speedometer on a car.

Digital models give a specific readout of the exact voltage measured. They can be extremely accurate and helpful for measuring voltage.

When using a voltmeter you should turn the dial or switch to AC. AC current allows voltage to flow through the leads and allows the voltmeter to display an accurate readout.

To check voltage over any R wire: If your breakers are off, you will need to turn them on. On most multimeters, AC current is designated by VAC or V~.

Follow this guide:

Set the dial to 200 VAC.
- If the multimeter doesn’t have a 200 setting, choose 100 or 250 VAC.
- The general rule of thumb is don’t set it too high (500+) or too low (50).Place the red lead on the R wire.
Place the black lead on the other wire being tested (W1, Y1 or C).
The normal readout should be somewhere between 20 and 30 V (24 V is most common).
Suggestions to keep in mind if you get a very low readout or nothing at all:
- Test it one more time.
- Verify settings on the voltmeter are correct.
- Ensure that leads are plugged in properly.

Please keep me posted.

I appreciate the help, Zoe.

Regards,

Jenelyn

Re: Lux 1500 to Nest

georgep — Sun, 03 Dec 2023 13:42:20 GMT

Sorry if this is a repeat post, I thought I posted this the other day.

I did getting readings off of the wires - as follows.

RH + W = 27V

RH + Y = 14 V

RH + G = 27V

RH + B = 27 V

RC + B = 27 V

RC + O = 27 F

Let me know if you think this is significant to get the Nest to work.

thanks

Re: Lux 1500 to Nest

zoeuvre — Sat, 23 Dec 2023 18:16:06 GMT

Hello georgep,

Thanks for the information, and I'm sorry for the late reply. The voltage you got with your RH wire and Y wire is only 14 V, which is considered a very low voltage. If that's the case, I recommend you contact a local HVAC technician to properly ground the Y wire to 24 V, and then let us know how it goes.

Kind regards.

Zoe

Re: Lux 1500 to Nest

georgep — Mon, 01 Jan 2024 13:45:09 GMT

Thanks for the reply. I am guessing that I can check out this issue but just not connecting the Y wire now as it would only be needed for cooling. Correct? Thanks

Re: Lux 1500 to Nest

Jenelyn_O — Tue, 02 Jan 2024 16:50:51 GMT

Hi there georgep,

You're right. Your Y wire is responsible for your cooling. You can disconnect it for the meantime, but we suggest to get it fixed right away for you to avoid any inconvenience in the next season.

I appreciate your input, Zoe.

Best regards,

Jenelyn

Re: Lux 1500 to Nest

georgep — Fri, 26 Jan 2024 22:11:33 GMT

Thanks, I did disconnect and the yellow for cooling and the same issue occurred. Any other last chance ideas?

thanks