Display not waking on approach

[Roark1]

I have had my Nest Learning 4th Gen Thermostat for about a month. Today it stopped showing the display upon approach by itself. How can I restore it? I have removed it from the wall and replaced it as a first step without success.

[Patrick_Caezza]

@Roark1 

How do you have it wired?

Is there a C wire installed?

[Roark1]

@Patrick_Caezza

There is no C wire hookup and it is only a gas heater and no AC.  Actually, when I went into settings and changed the display to "weather" it then started working properly by turning on when approaching. I am not sure that was what solved the problem or is was coincidental.  Thanks for the help and any insight is appreciated.

[Patrick_Caezza]

@Roark1 

Hard to say if it is just a coincidence or not.

I recommend that a C wire is always used. I have found that having the C wire will stop most power problems that might happen down the road.

[Roark1]

@Patrick_Caezza

I remember at installation there being a question about a jumper wire but the installer who did it (not an electrician) didn't use it. Would you mind describing what the C wire should connect to and how this helps. I currently have just 2 wires, am Rh and W1 connected. Thanks very much.

[Patrick_Caezza]

@Roark1 

The C wire is the return path for the R (24vac) wire. This allows the thermostat to have constant power. Without the C wire the thermostat "steals" power from the furnace.

The jumper was probably between the Rc and Rh terminal and isn't needed.

Check to see if you have any extra wires at the thermostat. If you do, you should be able to add a C wire easily. 

Look inside the furnace/air handler and you should see a terminal block on the control board. This terminal block will have several different colored wires attached to it and there should be a label printed next to each terminal.

You will add the spare wire to the terminal labeled C and then connect the spare wire to the C terminal on the thermostat. Be sure to turn the power off before you make any changes.

If you are not sure, take a picture of the furnace/air handler and its control board and post it here

[Roark1]

@Patrick_Caezza

Attached are two images showing existing wiring which is probably circa 1958, when the house was built. One is of the existing wiring coming from the wall where the thermostat is and the other is located next to the furnace itself.  If I was supposed to take off the cover of the furnace and take another photo I will do but thought I would wait to see if even necessary. Barring having it rewired, I am not sure I have other options with this setup.

Thanks!

[AxelD]

Hi @Roark1,

Thanks for replying and sharing those photos. They're very helpful! I noticed that your system is a two-wire system. As @Patrick_Caezza suggested, it's always recommended to install either a C-wire or a Nest Power Connector to ensure your Nest Thermostat receives a consistent and reliable power source.

Please try installing one of these options and see if that resolves the issue.

Thanks again to @Patrick_Caezza for his assistance.

Regards,
Axel.

[Roark1]

Hi @AxelD

Thanks for the suggestion. The suggestions go beyond my basic capabilities as a novice and DIYer/homeowner. It sounds like something a professional installer may need to do.  I appreciate your help and that of @Patrick_Caezza.

Roark