Ecobee integration cycling my A/C?

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I’ve noticed an odd behavior after a recent update. When I turn on our A/C from HA and the temperature is reached, I can hear the A/C periodically being turned on and instantly off again.

Basically it makes that hum like it’s powering up the motor, but it never gets started and shuts off right away. When I turn the A/C off from HA, the problem stops.

I noticed after a recent update that the Ecobee integration is now showing the temperature with an additional single decimal point. That’s cool, I thought. I like the increase in precision.

But after this problem started it got me thinking that perhaps this extra digit of precision related to the problem. Today when the temp got hit I noticed that HA reported the temp as 76.4. The trigger temp is 76.

Maybe what’s happening is that the partial degree above the target is causing the A/C to be turned on, then the Ecobee itself looks at the temp and turns off the A/C right away because the temp hasn’t hit the next full degree in temperature difference.

Whatever is the actual cause, I’m certain that this was not happening before. Something related to recent updates is causing this. It correlates to the appearance of the sub-degree display, but I don’t know if that’s relevant or not.

Note that I’m currently running HA core-2021.6.6. I have no Ecobee related automation. The Ecobee integration is as-is from when I added it over a year ago. I don’t think I made any changes (except maybe to deal with some token format change forced by Ecobee a while ago).

Probably unrelated, we have a LilBee whose battery is going bad. I see reports of this on the Ecobee unit itself, and occasionally I get an email.

I haven’t replaced the battery yet. But I think all that the LilBee does is report occupancy to the Ecobee. I can replace the battery, but I doubt this problem is going to go away. We’ve had low battery LilBee’s before without this problem (or at least I never noticed it).

Anyway, any suggestions would be welcome. At this stage I’m afraid to run my A/C because it can’t be good for the motor to flood it with power then turn it off right away over and over.

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FYI, I replaced the LilBee battery. No change, unsurprisingly. The problem still happens.

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When you say “turn on AC from HA” do you mean change the mode to AC or do you have an automation that turns on or off based on house temperature through ha? Or are you setting a target temperature?

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What I mean is manually turning the HVAC unit to A/C by pressing on the snowflake button in the thermometer GUI in a Lovelace page. I have no Ecobee related automations.

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What you’re describing sounds like a short cycle, where the compressor engages and quickly turns back off. Modern thermostats have protections built in to prevent compressor wear and this sort of thing. Does the fan inside the home also cycle quickly?
Ecobee does use some pretty advanced anticipator settings, which can only be adjusted from the thermostat itself. Google “Threshold settings for ecobee thermostats” for some support docs on this.
These thermostats measure in .1 increments, but don’t usually display them. If your anticipator settings are on manual, they could be set ultra sensitive. Did you install the thermostat or did a contractor? Which model do you have? And, what type of HVAC setup is installed? Heat pump, split, etc.

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The issue is with the ecobee and not the integration. The integration just allows remote control of the ecobee, it does not actually tell your HVAC to turn on or off. The on/off control depends on the settings of the thermostat. To verify/test, temporarily disable the ecobee integration and see what happens. I’ve had problems in the past with ecobee and their “smart” algorithms. Mainly the feels like feature that attempts to calculate the actual temperature when factoring in humidity. This feature was causing my A/C to run way more than it should and short cycle. Also you can set the setpoint differential to something larger like 1.0 or 1.5 degrees. You sacrifice a little bit of comfort, but your system runs a little bit longer each cycle and theoretically fewer cycles. Remember, you’re not just conditioning the air in the house, but also everything inside it. If you just meet the temperature setpoint as fast as possible then things like exterior walls, windows, things in the sun, etc. are just heating it right back up. But now I’m talking about HVAC setup and troubleshooting rather than anything with HA or automation.

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Thanks everyone for the replies. I’ve done a bit more experimentation and have some more info.

I looked at the thermostat itself as well as the Ecobee web app settings. There was nothing weird that I could spot, like sub-degree set point values.

Under threshold settings I see the following:

  • Auto Heat/Cool: enabled
  • Heat/Cool min delta: 5 F
  • Configure staging: automatically
  • Compressor min cycle off time: 300 sec
  • Compressor min outdoor temp: 35 F
  • AC Overcool max: disabled
  • Heat min on time: 5 min (default)
  • Compressor min on time: 5 min (default)
  • Temperature correction: 0 F
  • Humidity correction: 0%
  • Thermal protect: Disabled

The model we have is an ecobee4. It was set up by an HVAC contractor originally. We just have A/C and a gas fired furnace for heat. No heat pump, or anything fancy.

I did notice that the programmed schedule was set to 78 for the A/C to kick in. But on the thermostat there was a holding temp of 76 for heating and 76 for cooling. This holding temp was set by me from the Lovelace UI quite a while ago.

As an experiment I cleared the holding temps, and changed the schedule to be 76 instead of 78. I then turned the thermostat from off to on at the device itself.

When the house got hot enough, the A/C kicked in. When it turned off after reaching the desired temp, the A/C did not short cycle any more. It was completely well behaved.

So as a binary chop I turned off the A/C at the device, and enabled it via the Lovelace UI. I only enabled cooling. I didn’t change the holding temp. This was while the A/C was off because the house was cool enough.

When it got hot enough the A/C kicked in again until the temp was reached. And again the A/C was completely well behaved. No short cycles.

That’s all the testing I can probably do today because everything is cooling off. Tomorrow I think I’ll try using Lovelace to override the holding temp with a lower value (as it was before I started playing with this stuff today).

I’m a little suspicious of the dual holding values of both heat and cold. I never saw that when setting a holding temp from the device. Probably because I only ever set either the cold or the heat holding value, whereas it looks like the HA integration sets both.

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