topic Re: Fan settings not working in Nest Thermostats

Fan settings not working

Fraomame — Wed, 17 Nov 2021 18:10:00 GMT

Hello,

I am having problems with my fan settings on my 3rd Generation Nest Thermostat.

When my heat comes on the fan blows on low speed. I have HVAC fan speed set to high.
When my Every Day fan comes on, it blows on low speed. I have my everyday fan set to run at medium

If I manually turn on the fan, it works at all speeds (low, med, high)

This problem just started a couple weeks ago and I have not made an changes to my furnace wiring or to the Nest.

What could be the problem?

Re: Fan settings not working

Alissonff — Mon, 20 Dec 2021 02:09:11 GMT

I am having the same issue, it was working before and started a couple of weeks ago.

Re: Fan settings not working

RezaB — Sun, 16 Jan 2022 15:47:40 GMT

Same issue. Any help?

Re: Fan settings not working

Alissonff — Sun, 16 Jan 2022 16:12:50 GMT

Seems like that the issue is happening after an update that came in November

Re: Fan settings not working

Fraomame — Tue, 18 Jan 2022 12:25:44 GMT

I agree. I called Nest Support and they didn't agree with me when I suggest this.

Re: Fan settings not working

RezaB — Tue, 18 Jan 2022 15:34:33 GMT

Factory resetting my thermostat solved the issue. But it’ll happen again since there is no way to prevent it from updating firmware and Nest support chat was absolutely no help in this regard.

Re: Fan settings not working

Fraomame — Tue, 18 Jan 2022 15:39:17 GMT

Nest Support asked me to factory reset but unfortunately, it didn't help.

Re: Fan settings not working

AV_95662 — Thu, 20 Jan 2022 05:40:39 GMT

Just had a new Carrier air handler unit installed with multi-speed fan. They installed the Nest Learning Thermostat, and it only will run on low speed. Followed the online instructions to set fan speed, however the option to choose fan speed doesn't exist in the applications (PC, iPhone) or the thermostat itself. 1/19/2022

Re: Fan settings not working

VulkRider — Fri, 15 Jul 2022 14:36:05 GMT

My fan won't run except on low. There is no option to change the fan speed. The fan control only allows you to set the time you want it to run. I had a Honey... thermostat with the exact same wires in the same letter codes. Wires Y1, Y2, G, OB, Rc, W2 aux, C. Nest Model A0013., With the outside temp about 85" the temp inside would not go down to 76" which I had the Nest set to, in fact it ran all day and lost ground (got warmer in the house). I even removed the filters to allow more air in. About 8" from the vent you could not feel the blowing at the vents. I think it was blowing at low speed. My fan motor in the blower unit only has wiring to the C (Full speed) terminal on the fan (B,C have no wires). Reconnect my old Honey... thermostat at 1:00 A.M. Same exact wiring code letters, put the filters back in place. About 20 minutes I went down to see if it had made a dent to get down from the 78' it was inside to the setting of 74". It was already down to 74" and the heat pump cycled off. The Nest ran all day and the temp inside actually went up! Heat pump w/ aux heat, electric powered, no other fuels. The Nest test confirmed all 7 wires were connected, fan test was good.

Re: Fan settings not working

TyFred2 — Sun, 24 Jul 2022 23:50:56 GMT

Same problem the temp will not go down since the nest has been installed. The fan is running slower then before. And i have a G wire and no fan control.

Re: Fan settings not working

TalkToPaulDotCo — Mon, 01 Aug 2022 04:25:08 GMT

I'm having the SAME issue and it all started when I upgraded to the nest.

So you went back to an old LCD screen thermostat? Are there any older LCD thermostats that can be controlled by the phone or wifi?

Re: Fan settings not working

tmax60 — Tue, 16 Aug 2022 22:19:01 GMT

Same here. Brand new Carrier heat pump and air handler system. Honeywell thermostat, fan ran higher speed. Nest thermostat, fan running lower speed. Still cooling but cycles are longer than with Honeywell. Single stage system, so fan speed adjustment not available on Nest

Re: Fan settings not working

ChadWillms — Mon, 22 Aug 2022 22:21:58 GMT

I am having this same issue, previously the fan would change speeds as needed when healing/cooling. I didnt notice till about March that it only runs on low (when set to auto) unless i manually change the speed to med or high.

I have tried the reset (thanks to this forum) but it did not resolve the issue.

Re: Fan settings not working

GregSid — Sun, 13 Nov 2022 00:30:23 GMT

My Carrier system has been running OK for year and a half. Suddenly the fan / AC unit does not respond to control. Yesterday and today it would say the fan was running but it was not! Dispalys desired temp but does not cool.

Re: Fan settings not working

Jhonleanmel — Wed, 16 Nov 2022 18:40:12 GMT

Hi GregSid,

Thanks for letting us know about this.

A few questions:

What type of Nest thermostat do you have?
Did you try using the Help Center or troubleshooter before contacting support? If so, which steps have you tried already?
What type of system do you have? (Heat Pump or conventional type)
- For Heat Pump:
  - Did you check O/B wire configuration and tried changing the O-wire to B-wire configuration or vice versa?
  - Did you try swapping O/B and G wire on the Nest terminals then test for cooling and heating?
- For conventional type:
  - Did you verify if Fan and Heating still work?
  - If both still work, did you try swapping Y1 and G wire then call for cooling?
Did you also try swapping Y1 and W1 then call for heating?
Did you turn off the power to your HVAC system?
- Are the breakers turned on?
- Did you recently experience a brownout or blackout?
- Did you have any construction or maintenance work done on your home?

Best,

Mel

Re: Fan settings not working

Jhonleanmel — Sat, 19 Nov 2022 19:19:19 GMT

Hey GregSid,

Checking back in should you still have some questions here. Let us know by replying to this thread.

Best,
Mel

Re: Fan settings not working

Jhonleanmel — Sun, 20 Nov 2022 19:37:04 GMT

Hi GregSid,

Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.

Thanks,
Mel