Dirty coils on the AC can cause an AC to freeze up and even dirty air filters can cause an AC to freeze up or low refrigerant.
An AC that keeps running after the temperature is reached is most often caused by a faulty thermostat or even low batteries if the thermostat has batteries.
When your air conditioning system keeps running and never seems to shut off, the problem can also be linked to a number of of other conditions and malfunctioning components – frozen evaporator coils, a clogged air filter, a bad electrical relay switch that needs to be replaced, the fan blowing constantly, dirty condenser coils.
You will know if your AC needs freon or refrigerant by the signs of low freon or refrigerant which include.
Ice on the refrigerant lines or coils.
Air from the vents is warm and not cold or not as cold as it should be.
Increase in electric bills.
The AC runs constantly without cooling the home.
Or you hear any bubbling or hissing sounds when the AC is not running.
If your AC is not cooling then yes you should turn it off or at least switch the AC to fan only mode.
If the AC is not cooling then it is most likely the AC coil is frozen up due to low refrigerant or dirty AC coil that needs cleaned.
A dirty air filter on the AC can also cause the AC to not cool or freeze up.
Turning the AC off can allow the froze up AC to thaw out and then work again.
The most common reason for an AC to switch on and off automatically too soon is a dirty air filter or dirty evaporator coil that can become frozen and cause the AC to turn on and off.
Your AC may also be low on freon or refrigerant or it may have developed a refrigerant leak leading to the AC freezing up and shutting off.
The cost to replace an air conditioner thermostat is between $80.00 to $200.00 for parts and labor.
If you replace the air conditioner thermostat yourself then the cost to replace the air conditioner thermostat ranges from $20.00 to $200.00 or so depending on the cost of the thermostat you buy and are installing.
An air conditioner thermostat lasts between 5 to 10 years although some air conditioner thermostats may last as long as 15 to 20 years.
Your AC may work if the thermostat is bad if the thermostat is just not reading the correct temperature.
In some cases the AC may work but not shut off when it reaches the correct temperature but if the thermostat is not working at all then the AC will not work as it needs the thermostat to tell it when to turn on at a set temperature.
An AC should run for around 30 minutes to an hour on at a time on a 95 degree day or if your house is not insulated or insulated really good then the AC may run for several hours or all the time on the 95 degree day.
On less hot days then the AC should run for 15 to 20 minutes at a time before shutting off.
On 100 degree days your AC should run almost all the time or sometimes the AC may run for a few hours and then shut off for 20 to 30 minutes if your home is really insulated good.
It's normal though for an AC to run all the time when it's really hot out as it takes more effort to remove all that heat that can buildup in the home on really hot days.
The recommended temperature setting that you should set your AC at if it's 100 degrees outside is 74 F to 72 F.
However for me personally that is too warm for me and I prefer to set my AC at 60 F as I like it much cooler when it's really hot out.
A properly sized AC whether it be a window AC or central AC should take around 18 minutes to drop the house or rooms temperature by 1 degree.
It should take a proper sized AC at least 36 minutes to cool a house down by 2 degrees and 54 minutes to cool a house by 3 degrees.
To cool a house down by 4 degrees it should take the AC around 1 hour and 12 minutes.
It's better to run a window AC or central AC all day to keep the home or room cool enough so that it does not get too hot.
However if you are at work and want to save money then you could shut it off and only run the window AC at night or when you're home.
Leaving the window AC on all day on a higher temperature is better as it means the room or home will be cool enough so that it's not hot when you get home and the window AC won't have to work as hard to cool the home or room down.
A window AC should run between 12 to 16 hours per day although the window AC can run longer if needed.
A window AC that is properly sized should run and then shut off a couple of times an hour although on really hot days the window AC may run longer before cycling on and off to keep the room cool.
It is not bad to leave a window AC on 24/7 as the window AC will be just fine and is designed to be ran 24/7 if need be.
The compressor on the window AC and the fan motor are thermally protected so they would shut off on their own before they got too hot.
It is okay to run a window air conditioner 24/7.
A window air conditioner is designed to be ran 24/7 or as often as you need it too to cool the room or home down.
There's no need to let the window AC rest as the AC compressor and fan motor are thermally protected so that if they did get too hot they would shut off on there own until they cooled down.
In the summer months my window air conditioners stay on 24/7 to keep my home cool although if I'm away from my home longer than a few days then I shut it off.
You can leave an AC unit in the window all year but you should use a window air conditioner cover over the inside and outside of the window AC to prevent cold air from coming into the house and make sure the window AC is sealed around the window also.
Some people prefer to remove the window AC after summer is over but some people prefer to leave the window AC in the window all year which is also okay.
A window AC should run between 12 hours to 16 hours per day although it's okay if you need to run your window AC all day to keep the home or room cool.
Shutting the window AC off completely when you're gone away from home means the house will heat back up and then when you return the window AC will need to work harder to remove that heat.
So it's better to just leave the window AC on but turn the temperature up a bit so that it keeps the house just cool enough so that it does not get too hot.
Outside temperature does affect a window air conditioner because the hotter it is outside the hotter it also gets inside your home which means the air conditioner has to do more work to remove all that extra heat.
On really hot days the window AC will need to work harder and longer to cool your home or room down than it would on a cooler day.
For example if it's only 80 F to 85 F out then the window AC will cool down the house or room faster and not have to work as hard but if the outside temperature is hotter such as between 90 F to 100 F or hotter then the window AC will need to work longer and harder to remove that heat and keep the space cool.
On really hot days you may need more BTU power for the air conditioners to cool the house down.
The window AC will run longer on really hot days than it would on cooler and less hot days.
Window AC units do have thermostats which are either located in the control panel or in the thermostat knob where you turn it to high cool, low cool or medium cool.