Heat won't turn off

[Joanb4464]

I just installed my nest thermostat and the heat keeps running even though the thermostat is off. It also keeps running after it hits the designated temperature. Help!!

[Houptee]

Do you have pics of old thermostat wiring?

Is it a gas furnace hot air system with a/c?

[Joanb4464]

Yes, it is. The fan runs constantly, even when the thermostat is off.old wiring

[Don716]

I am having the same issue I am upgrading from a cheap Honeywell thermostat 2 wire . I think the best requires a 3 wire (common) not positive on that yet tho looking for answers . Don’t try to call customer service they are useless 

[Houptee]

Looks like you have basic system wiring so just connect same wires to Nest but make sure white wire (heat) is on W1.

Make sure you tell it you have a hot air heating system if you have ductwork.

[Joanb4464]

It is wired correctly. Told it gas furnace with forced hot air

[Joanb4464]

Should I try switching the white wire to OB? It seems to be the same on the old thermostat

[Houptee]

Ob is only needed for heat pump systems. 

If you are sure you have a air conditioning system and a gas furnace then no OB is necessary. 

Do you have pics of the wires connected to the equipment so we can verify everything matches up. 

[Joanb4464]

what equipment are you referring to?

[EdwardT]

Hi folks,

@Houptee and Todbone, thanks for the help!

@Joanb4464, I'm sorry to hear that you're having an issue with your Nest thermostat. To isolate the issue, could you check if the fan would still run if you remove the display of your Nest Thermostat?

Thanks,

Edward

[Joanb4464]

@EdwardT  yes it does run without the display

[EdwardT]

Hi Joanb4464,

Thanks for the response. Could you also try removing the G wire? Make sure that you turn off your breakers before touching any wires.

Thanks,

Edward

[Joanb4464]

@EdwardT  ok. i removed it

[EdwardT]

Hi Joanb4464,

Is the fan still running? If you haven't yet, you could also check this link for some troubleshooting steps you could try.

Thanks,

Edward
 

[Joanb4464]

@EdwardT  yes still running. i have a specialist scheduled for this afternoon

[EdwardT]

Hi Joanb4464,

Thanks for trying. If the fan is still running without the G wire connected to your Nest Thermostat, that means that it's not the thermostat that's causing the fan to run. Let us know the technician's finding once they look at it.

Thanks,

Edward

[Jeff]

Hey Joanb4464,

I just wanted to follow up to see if the technician you had come by was able to sort anything out and provide any answers for you. Let us know if you still have questions or if things worked out.

Thanks,

Jeff

[Jeff]

Hey everyone,

It looks like we've slowed down here. We'll be closing up the thread in the next day unless anyone else has any input or needs anything else. If so, just let me know and we can keep this open a bit longer.

Thanks,
Jeff

[Todbone]

The white wire (which controls the heat) could be touching red somewhere, causing the heat to operate non-stop. Do you have an extra wire to substitute the white wire? If so, you'd have to use the same color wire at the indoor control board.

[Joanb4464]

heat is not operating. fan runs continuously but no heat. The fan runs even if the thermostat is off