AC kicking on
 

AC is kicking on when house temp is below thermostat setting- any ideas why?- thank you

It could just be the fan trying to draw down the humidity. The ac will also drive a degree or two below set point so it’s not cycling on and off all the time.

I’m guessing you’re in a new house? lol f so make sure to schedule the walk through with the AC contractor. They’ll run through the system with you and probably tweek a few things.

Humidity perhaps.

thanks- even with no humidistat or dehumidifier installed-?

Most of the HVAC controls have a humidity setting, as I recall ours is around 55%, and then the A/C turns on to control the humidity level. Ours also indicates that it is on for humidity control.

There is a humidity setting that you can turn off. If it is on, the AC will cool down the house to about 3 degrees below the temperature setting to satisfy the humidity setting. Check the thermostat to see if the humidity option is selected. If so, turn it off. I always leave mine off.

thanks to all for the quick responses

You have had a rough day getting stuck at home garbage now A/C.

Of course there's humidity control....
 

perhaps you would be wise to pay more attention to how your heating and cooling system works.

If it's raining outside it's 100 percent humidity. The ac removes humidity out of the air and makes it seem cooler(think of perspiration evaporation as it's how the human body cools itself). So while it seems the ac is running it's likely the fan drawing in humid air and removing some of that dampness.

Note that the optional humidity setting on your HVAC thermostat will attempt to lower the humidity in your house by running the AC longer than it needs to run to satisfy the temperature setting. So, it will remove extra moisture from your house by reducing the temperature to about 3 degrees below what it is set for. You can set the temperature to 72, but, when the humidity is high, you will actually get a temperature of 69. This is a good feature for snowbirds when the house is not occupied because it allows you to set the temperature to a higher setting (about 80 degrees) and save on electricity. When the humidity goes up, the AC will automatically run longer to reduce the moisture in your house. But, when the house is occupied, the optional humidity setting may make the house uncomfortable because it will get too cold when the humidity goes up. So, I recommend turning on the humidity control only when the house is unoccupied. Just my opinion.

Part of, "air-conditioning," is humidity control. You have a drain line outside your home. That drip you see is humidity removed from the air. Unless you have a very old system, there is a humidity setting on the air conditioning control-where you set the temperature. It is raining-hurricane. To control the humidity your AC may well run cooler than the set temperature..

The AC will run cooler only if the optional humidity control is turned on. See Post No. 10.

We keep our humidity set at 55% year round. The last thing we want is a mold problem. When we are there the temp is set to 70 but we are not there much.

It’s bringing the humidity down.

was waiting for someone to say that to op. Always think big picture regarding your home, especially about mold.

you'll have fun when temperatures drop near 40 and you start getting messages on your thermostat.

My thermostat has been set at 78 for more than 5 years, with the optional humidity control feature turned off. No mold.

What might cause temperature increase inside a house? Electronics? Lights? Oven? Dryer? The human body?

If you have an ecobee unit, here's a video. Overcool to lower humidity:
https://youtu.be/CcnGqkMWMns

None of those things will have much of an effect. The most effect comes from the outside air temperature and an inadequate amount of insulation and air leaks around windows and doors.

Replace all light bulbs with LEDs, but not for heat. The biggest savings will come from a reduction in electricity usage. An incandescent bulb uses about 6 times the amount of electricity as an LED.

That is a good explanation of the humidity control feature on most thermostats. Today, the outside temperature is 71 and the humidity is 96 percent. An unusual day in The Villages. The humidity inside my house is 68 percent, with no cooling being used at all because the thermostat is set at 78 degrees, which is a comfortable temperature for me. On hotter days, the humidity would be about 40 to 50 percent because the AC would be operating. Do I want to turn on the humidity control feature to try to reduce the humidity to 60 percent? No, because the temperature would drop to about 74 degrees and the house would be too cold. But, it is a personal choice. I have never had a mold issue.

We've been here in a new home since fall of 2019. To get used to the heat and humidity, we got accustomed to home temp set at 77°.

We have Carrier HVAC and Ecobee thermostat.

Only recently, in the last several weeks, have we experienced the AC cooling down the home to below the Ecobee 77° AC setting. Just a degree or two. It's a combination of the humidity control, and an Ecobee automatic software update. To compensate, we upped our home AC setting to 78°. Still quite comfortable to us.

Why ask the question here versus calling an a/c company and save you and us time reading all the responses that may be incorrect - just wondering!

Do you have an AUTO setting? If so, your A/C might be trying to maintain your Heat/AC setting.

Good point. I use the AUTO setting, but my thermostat will not allow the heat and cool temperature settings to be set at closer than 4 degrees apart. So, if the cool setting is 78, the heat setting must be at 74 or below.

Oh I am sorry- I forgot I had the power to FORCE you to not only read a post, but also reply to it.
But looking at your prior posts, it seems like this is your "thing" to nullify other's questions. So the question is- who is actually the one wasting their time- seems to be YOU

Check to see if your AC heating element is kicking on when the temperature drops in your house. Our AC technician told us it is best to turn that option off in settings since it uses huge amounts of electricity and we don't get that cold here in the area.

Pat E
 

Chances are the pan under your AC is not draining. The drain pipes here get clogged with gunk. Look at the pvc pipes in front of the AC. The one sticking up has a cap on it that you can remove. Put your hose on it and turn the hose on low. It should push the mess out. The reason you’re AC turns off is because it has a safety valve on it to keep your pan from overflowing and flooding your house. This should be done once a month to keep the pipes clear

mold can grow behind walls, but, hey, it's your party

Any single stage AC system will control relative humidity by lowing the temperature. However, If you have a staged AC system, the humidity is controlled independent of the AC temperature setting. When a staged AC system is running to control humidity, it has very little effect on the temperature. It runs similar to a dehumidifier. It is one of many advantages of a staged HVAC system

I have a fairly new a/c system and don't see a humidity setting. I recently had a mold problem in my home and until then never paid attention to the level. It was averaging 55. I had a tile floor installed at the suggestion of the leak guy and the remediation guy. Now it hovers over 60 and up to 70. Any advise? Munn's has not returned my call about this.

I would write down the model number for the thermostat and then Google and download the operating manual. It will explain if you have a humidity control feature and how to use it.

A staged AC unit can run at a low speed and remove moisture from the air by running longer, but it is still cooling the air. A real dehumidifier will cool the air to remove moisture and then reheat the air to maintain a desired temperature.

On ours it’s called “over cooling” and can be turned off in the settings menu. Kicks on to lower the humidity level.

In a storm a few months back, my a/c thermostat got hit outside. My a/c wouldn’t turn off until I put it up to like 92 degrees. They came out and fixed it. It was reading the wrong temp inside my house.

It's all ball bearings nowadays. Now you prepare that Fetzer valve with some 3-in-1 oil and some gauze pads. And I'm gonna need 'bout ten quarts of anti-freeze, preferably Prestone. No, no make that Quaker State.

Humidistat is kicking on

If you don't have a humidity cycle on your HVAC, you have a serious problem. It's a near-certainty that you do and you just need to learn how it operates.

My wife will be cold in the middle of a 100 deg day. I'll be wearing shorts and a tee shirt. She'll be dressed like a female version of the Michelin Man. Having moved here from the Southwest where there was no humidity problem, I had the hardest time explaining the humidity cycle to her. She kept insisting I shut the air conditioner off.

I'm sure the posters who have turned off the humidity cycle of their HVAC and say they have no mold mean well. However, it is poor advice. Mold grows inside walls. By the time mold is visible on an interior wall, there is a serious problem with the house.

I splurged,I invested 49cents on a set of novelty teeth