topic Re: Nest learning thermostat 3rd wiring in Nest Thermostats

Nest learning thermostat 3rd wiring

LukeCypress — Sun, 13 Aug 2023 20:17:13 GMT

Is my system working with nest learning thermostat 3rd? Is the trial below Right?

W1 => W1

W2 => W2 AUX

G => G

Y => Y1

R => RH or RC ???

B => C ???

Re: Nest learning thermostat 3rd wiring

CoolingWizard — Sun, 13 Aug 2023 22:39:39 GMT

@LukeCypress ,

Do you have a Heat Pump?

Do you have a Gas or Oil furnace

AC Cooling Wizard

Re: Nest learning thermostat 3rd wiring

Jenelyn_O — Thu, 17 Aug 2023 15:57:59 GMT

Hi there,

Thanks for posting in the Google Nest Community forum. I just want to check if you managed to see the response above. Please share with us the needed information, as it will help us to move forward.

Also, please share with us the photo of the wires connected to your HVAC control board. Ensure that the labels of the wires are visible.

I appreciate your input, @CoolingWizard.

Best,

Jenelyn

Re: Nest learning thermostat 3rd wiring

LukeCypress — Sat, 19 Aug 2023 19:46:33 GMT

Hi Yes

I have heat pump and gas as well

Thanks

Luke

Re: Nest learning thermostat 3rd wiring

CoolingWizard — Sun, 20 Aug 2023 22:54:59 GMT

Your cable labels are on the outside edge of your Thermostat.

R - Red Wire, goes to nest Rc

O - White Wire, goes to Nest OB

Y - Yellow Wire, goes to Nest Y1

G - Green Wire, goes to Nest G

B - Blue Wire, goes to Nest C

W1 - Brown Wire, goes to nest W1, Duel Fuel system

Your system is what is referred to as a duel fuel system. Your Heat Pump is considered the primary source of heat it fuel is electricity. The gas Furnace is the second source of heat and it’s fuel is natural gas. In a duel fuel system, there will be a point when the outdoor temperature is so cold that your natural gas furnace is more efficient for generating heat. Depending on the efficiency of your heat pump, this can be anywhere from 25°F down to -5°F. The point to switch over can be calculated if you have the desire to gather the data and make calculations. Basically, you need to convert the BTUs of heat converted to watts of energy. As it gets colder outside, the heat pump typically becomes less efficient. Your gas furnace is rated in BTUs of heat output, but you need to know the volume of natural gas in order to convert that to watts of energy.

I know this is a lot to think about.

AC Cooling Wizard