Nest Thermostat Low Battery Woes

[Estabde]

I hooked up my new Nest Learning Thermostat with a 2-wire setup (W and Rh) without a c-wire and it seemed to work but the boiler runs constantly even when the room temperature is higher than the thermostat is set to. The battery runs low after a day or two so I bought a Power Connector and after I hooked it up I get an error message that the Rh wire isn’t detected. Does anyone have any ideas what the issue is? Before I pay an electrician to run a c-wire I want to rule out other possible causes.

[Jenelyn_O]

Hi Estabde,

Thanks for reaching out in the Google Nest Community forum. I'm sorry for the delay. A few questions: what is the make and model of your heating system? In what country are you located? Please gather your thermostat's power readout. 

You can follow this guide:

1. Go to your thermostat Quick View menu.
2. Go to Settings.
3. Look for Technical Info.
4. Select Power.

Also, check your power wire, and the end should be straight, fully inserted into the wire connector, and isn't corroded.

Google Nest thermostats detect wires by testing them in two ways: mechanically (is a wire inserted into the connector) and electrically (electrical current on the wire).

Stip and fix the wire:

1. Important: Turn power to your system off at the system switch or fuse box. This helps protect your system and thermostat from possible damage.
2. Pull the thermostat display off the base. 
3. Pull out one wire and inspect it.
   • The exposed part of the wire should be ⅓ to ½ inch long, clean and straight
   • Cut and re-strip any crooked or corroded wire ends
4. Re-insert the wire.
   Important: Make sure that the wire connector’s button stays down. If not, the wire isn’t fully inserted, and the thermostat won’t detect it. 
5. Push the display onto the base until you hear a click.
6. Turn power to your system back on.

Let me know how it goes.

Best,

Jenelyn

[Estabde]

Thanks. I live in Canada and our heating system is an NTI TX 151C combi boiler. It’s 5 years old.

[zoeuvre]

Hi there,

@Estabde, chiming in—thanks for the information. Could you provide the power readings of your thermostat's Battery, VOC, VIN, and lIN following the instructions given by Jenelyn above? Also, how did it go after reinserting the RH wire as also instructed above? 

Thanks for your help, Jenelyn. 

Best,

Zoe