Time to start cooling message

[ColinMckinty]

Hi

I've just upgraded to a Nest Gen 4 thermostat. The new thermostat has an odd behavior...when I move it to a lower temp. It says cooling starts in 2-3 mins. Have tried this new device in two different systems.  Is this expected behavior. My older Nest device didn't do this. 

Thanks 

Colin

[sicsacol]

Hi @ColinMckinty,

Thanks for reaching out to the community. I understand that when you change the temperature lower on your Nest Learning Thermostat (4th gen), you receive a message that says cooling starts in 2-3 minutes. I appreciate the information you've shared and the time you've taken to test it with two different systems. No worries, I'd be more than glad to assist you. To help with that, I have a few questions for you:

• When was your Nest Thermostat installed?
• After the time has passed, does your Nest Thermostat start cooling?
• Do you have a conventional HVAC system (furnace and AC) or a heat pump system (single unit for both heating and cooling)?
• Could you share a picture of your old and new wiring configurations? 

Any additional details you can provide will be helpful.

Cheers,
Jonathan

[ColinMckinty]

Jonathan

Thanks for replying and apologies for the delay in getting back to you. The two systems I tested this on were different. I'll start with the system that I want to use this on.

1. System One

This is an electric cooling and heating system. This had an older generation Nest Thermostat on and when I replaced it I would get the warning as mentioned before - after the count down the HVAC system would start but then abruptly shut off leaving only the fan run. 

I'm struggling to upload a picture here but the system has four wires - Yellow into Y1, White into W1, Red into RH and Green into Green. I mirrored this configuration when I connected the new thermostat.   

After sometime trying to work out what was wrong, I put the old thermostat back and normal operations started again. I took this new thermostat and tried it on a different system.

2. System two (test system)

This system is a heat pump used for cooling only. This time with the new thermostat in place, it operates as expected the first time you move it to cool to a lower temp but I get the 2-3 min wait until the system kicks if you move it from cooling to not cooling and back again.  It just seems odd that I get this warning when I haven't seen it on any of my other thermostats. This time I have Yellow into Y1, Green into Green and Red wires into Rh connected.   

I appreciate any insight you can share. 

Colin