Current Wiring to new thermostat

[MrCC]

How would this be wired? Down at the furnace the white wire is connected to the C lead at the circuit board. Where would the Blue wire get connected?

 

[Houptee]

Post a pic of system wires on the board.

Is this a heat pump A/C or a standard gas furnace with A/C?

[MrCC]

It is a standard gas furnace with A/C. The solid blue wire C coming off the circuit board is tied into the white wire that is at the thermostat.

[MrCC]

Take a look at the provided picture 

 

[Houptee]

Do you have a pic of the actual thermostat wires connecting to the furnace?

There a terminal strip with screws and the screws have labels next to them similar to the way the thermostat screws are marked.

We need to confirm if they used standard color code for the wires.

I think RC is your Common but without seeing what it connects to on the furnace I am not sure yet.

White is normally the heat wire and should go to W1 on Nest and W on furnace.

[MrCC]

Take a look at the following pictures 

 

 

[Houptee]

It looks like your system is only a Air Conditioner air handler, not a heater.

The white wire is being used as Common and the Blue and Red wires are both connected to + Positive power.

I do not see any connection in the pics that would turn on a heating system.

Is there a separate unit for heat somewhere else in the house?

[MrCC]

Yes there is a separate unit for heat. Baseboard water heat with a natural gas burner.

[Houptee]

Ok I would turn off power to the system.

At the system, take off the wire nut and move the Blue wire to the wire nut with the other Blue wire, and remove the White wire coming out of the thicker cable and wrap it around the cable it is not needed, keep only the 1 White wire (coming from the thinner 2 conductor red white cable). 

So you will have in that wire nut Blue, Blue, White.  Those are all your Common connections.

Next wire nut only Red and Red. Those are + Power

Next wire nut is ok Green and Green. Those are for Fan

Next wire nut is ok Yellow and Red. Those trigger the AC outside to turn on.

After that is all fixed go to the Nest and put:

Red to RC

Blue to C

Green to G

Yellow to Y

And during setup you tell it this is a AC only system.

I assume you have another thermostat for the heating system? Or do you want to control the heat with the same Nest?

[MrCC]

We would like to control both, the heat and a/c with the nest. That is the way it is currently working with the old thermostat.

[Houptee]

I don't see the heat control wires in the pics. Is that pic of the thermostat showing every wire currently connected?

The white wire is supposed to turn on heat, but you show white is wire nutted to the common blue wire at the air handler for the AC.

Where are the wires that go to the boiler hot water heating system?

[MrCC]

The picture of the thermostat shows all wires, a/c and heat that are connected.

[MrCC]

There are 2 white wires connected to the blue common at the a/c unit. Here are the other connections to the heating unit.

[Houptee]

Do you have pic of the boiler wires? 

Is the boiler in the basement, and the air handler for the ac system is in the attic?

I don't see how the wires you show can control the boiler.

[MrCC]

Take a look at the following pictures. Both units are next to each other. 

 

 

 

[MrCC]

Ok, let me try to chase that down. I will get back to you asap. Will probably be tomorrow sometime, if that’s ok. It’s getting a bit late in the evening here.

[Houptee]

The thermostat cable that leaves the boiler goes up behind the red switch and then goes where?

The wires at the thermostat look like they went directly to the AC unit so I'm trying to determine where the boiler wire goes to.

The thin wire with only a Red and White that go to the wire nuts that should go to the outside of the house and it turns on the AC condenser outside.

So I still do not see the heating wires connections to the old thermostat.

[MrCC]

Ok, let me try to chase that down. I will get back to you asap. Will probably be tomorrow sometime, if that’s ok. It’s getting a bit late in the evening here.

[Jeran]

Hey there MrCC,

I'm just checking up on this thread, do you have any more questions or need any additional help? 

Thank you so much for helping out on this thread, Houptee!

Best regards,
Jeran
 

[MrCC]

Actually, yes I do need to follow up with Houptee. I haven’t gotten a chance to do what Houptee asked was needed. I’m hoping to get it done by this weekend. Thanks.

[aatienza]

Hey MrCC.

Gotcha — keep us posted.

Thanks,

Archie

[aatienza]

Hey there,

I just wanted to follow up to see if you still need our help. Please let us know as we would be happy to answer any questions you may have. 
 

Thanks,

Archie

[aatienza]

Hey everyone,

Just checking in to make sure that you've seen our responses. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.
 

Thanks,

Archie