Nest 4th Gen short cycling fan while display on

[kslaats]

Hi,

I just finished a chat with an agent, but posting here to see if others are having the same issue as me.

I have had a Nest 3rd gen thermostat for many years and just upgraded to the 4th gen. Immediately after upgrading, I noticed the Nest would aggressively short cycle my system’s fan while the AC was running.

I realized the Nest only short cycles my fan while the display is on. I have a gas furnace, air conditioner, forced air system with wires connected to Y1, W1, G, and Rc. I previously had the Rc wire in the Rh port but was asked by the agent to move it to Rc. That did not solve the issue.

The agent recommended I turn Farsight off since the issue only happens when the display is on. The Nest battery has always appeared healthy at 3.87 volts.

I am frustrated since this worked just fine with the Nest 3rd gen and the only current solution provided was to turn off Farsight (which had huge improvements over the 3rd gen Farsight). Any others experiencing this issue or found a solution?

[CoolingWizard]

@kslaats, this sounds like you probably have a software bug in the software of that new nest fourth generation, and you need to insist that they open a case with the developers to get some input on this. 

AC Cooling Wizard

[kslaats]

Thanks @CoolingWizard. The agent told me they had escalated, but the case is closed. Any ways you know to ensure this is escalated and addressed?

I'd really prefer to avoid a C wire when it seems to be a software issue.

[Patrick_Caezza]

@kslaats 

This sounds like the typical no C wire problem.

Add a C wire if you can.

The Nest Learning Thermostat 4th Gen is so new most of use are still learning all of its quirks.

[kslaats]

Thanks @Patrick_Caezza. I replied to Cooling Wizard above, but I'd really prefer to avoid a C wire when it seems to be a software issue--especially when it worked great on my 3rd gen thermostat.

[Patrick_Caezza]

@kslaats 

There is a small chance that it can be a software issue, but the more likely chance is it is a Power issue.

The 4th Gen is a completely new device and has different power requirements than the 3rd Gen.

Just my opinion