topic Nest thermostat stats in Nest Thermostats

Trying to add power connector

es114 — Thu, 23 Mar 2023 20:42:32 GMT

Adding nest thermostat to a two wire newer Burnham boiler x-205. Thermostat wires are easy to identify at boiler. But they go into a fully loaded crimped wire connector attached to the circuit board. Also cannot identify where common is.

Re: Trying to add power connector

CoolingWizard — Fri, 24 Mar 2023 01:08:30 GMT

The transformer power arrives to the controller on P4. Normally there is pink wire and a brown. I noticed that your thermostat cable has a blue conductor and a green conductor wrapped around the outside of the cable sheath. You can locate the common of the two wires in P4 using a Volt Meter. Normally the Blue wires are the common side of the transformer. Using voltmeter set the setting to AC voltage, place, one lead in the pink connector of P4, and put the other one in the blue connector on P5 which is left of P4 and where two yellow thermostat wires connect. If you measure 24 V AC +/-5 V you found the common and it will be the blue wire. Now unwrap the blue conductor on your thermostat cable, and attach it to blue wire on the boiler control and at the thermostat attach the blue wire to the C and your Nest thermostat will now have a Common.

The AC Cooling Wizard.

Re: Trying to add power connector

es114 — Fri, 24 Mar 2023 02:42:41 GMT

Thanks for your reply. I believe the blue and green wires wrapped around the thermostat cable have been cut somewhere in the run to the thermostat. I will check to confirm. Also is there a common on P9 terminal 3? If I use the nest power connector, would the gray r and w go to P9 terminal 1 and 2?

Re: Trying to add power connector

CoolingWizard — Fri, 24 Mar 2023 03:20:46 GMT

The P9 connector is for the EnviraCOM communications. Typically Pin 1 is the communications line, Pin2 and Pin3 are 24 Volts. I am not sure if pin 2 or pin 3 is a Common.

Ken, The AC Cooling Wizard

Re: Trying to add power connector

es114 — Fri, 24 Mar 2023 12:20:20 GMT

So could could terminal 2 or 3 be used as a common?

Re: Trying to add power connector

CoolingWizard — Fri, 24 Mar 2023 14:01:09 GMT

I am not sure, you need to test it with a Volt Ohm Meter, as I stated, if a multimeter show 24 VAC +/- 5, between pin 2 and pin 3 then yes, one of those is going to be a common.

The AC Cooling Wizard

Re: Trying to add power connector

es114 — Fri, 24 Mar 2023 15:55:50 GMT

If I find approx 24 volts, how do I determine which terminal is the common?

Re: Trying to add power connector

CoolingWizard — Fri, 24 Mar 2023 16:45:44 GMT

Sometimes they tie the common side to the metal chassis. Try going between bare metal of the cabinet and each of those wires and see which one showed you the 24 V. The one that shows your 24 V will be the R and the other one will be the common

Re: Trying to add power connector

es114 — Fri, 24 Mar 2023 20:00:53 GMT

Your suggestion worked. Found that the common was terminal 3. Installed the power connector following the heat only instructions and everything is working normally. Thanks for your help.

Re: Trying to add power connector

CoolingWizard — Fri, 24 Mar 2023 20:08:04 GMT

es114,

glad to hear that it’s all working for you now.

The AC Cooling Wizard

Re: Trying to add power connector

CoolingWizard — Fri, 24 Mar 2023 20:28:13 GMT

I edited this adding colors to help you see the connections.

Re: Trying to add power connector

es114 — Sun, 26 Mar 2023 14:24:57 GMT

Thermostat working fine but just got an email from google indicating I need a power connector to avoid battery drain. Did a power test: vin 32.090v, Lin 385 (W), PS 385, WP 25. All on blue characters. Wiring info: connected W (P)-R. Power Status - Nest Power Connector detected. What could be wrong?

Nest thermostat stats

es114 — Tue, 28 Mar 2023 00:03:08 GMT

Finished installing with power connector. Are these numbers good? Power test: vin 32.090 Lin 385(W) PS 385 WP 25 wiring info W(P)-R. Power connector detected.

Nest not getting consistent power

es114 — Sun, 02 Apr 2023 13:51:48 GMT

Keep getting above message which indicates I need a nest power connector. But power connector is installed in heat only system with common wire connected to terminal 3 of envirocom port on burnham x-205 furnace. Multimeter indicates power is term 2 and common term 3. Is there another common I could use or are these false messages?

Re: Nest not getting consistent power

es114 — Sun, 02 Apr 2023 19:02:26 GMT

Tried installing a separate transformer. Followed the pro manual with transformer wires to common on power connector and bunch with r wires. Removed the jumper and no power. Checked the transformer wires while connected and got 27 vac. Removed the transformer and reconnected the common to term 3 on enviracom block put back jumper on power connector and got normal values with no error messages on thermostat. Why won’t anybody help?

Re: Nest not getting consistent power

es114 — Mon, 03 Apr 2023 14:53:00 GMT

Spoke to Burnham Furnace technical support. Confirmed that enviracom terminal 3 is common on my furnace. So what I’ve done to install the power connector is right. So why am I getting an n260 error message?

Re: Nest thermostat stats

Jenelyn_O — Tue, 04 Apr 2023 18:58:56 GMT

Hi es114,

Thanks for posting in the Google Nest Community forum. There are no power readings that will tell how good your Nest Power Connector is. If your Nest Thermostat says that your Nest Power Connector detected, that means it's properly installed and it's good to go.

Best,

Jenelyn

Re: Nest thermostat stats

es114 — Tue, 04 Apr 2023 19:36:27 GMT

Then why am I getting sporadic n260 messages? I have spoken with a Burnham furnace technician who says my power connector install is correct including the common?

Re: Trying to add power connector

Jenelyn_O — Tue, 04 Apr 2023 20:27:42 GMT

Hi es114,

Thanks for reaching out. I'm sorry for the delay and for the confusions. Could you please try updating your Nest Thermostat software? Go to your thermostat Settings then choose Version and select Update. Let me know how it goes.

I appreciate your help, @CoolingWizard.

Best,
Jenelyn

Re: Nest thermostat stats

Jenelyn_O — Tue, 04 Apr 2023 20:30:48 GMT

Hi es114,

We’ve duplicated your thread to the main one here. You’ll receive all updates on this issue on the main thread and we recommend updating and checking this thread when needed.

Thanks,

Jenelyn