![Dirty filter of air conditioner in female hands. Cleaning and washing maintenance](https://www.rd.com/wp-content/uploads/2018/07/10-Air-Conditioning-Mistakes-You-Can’t-Afford-to-Make.jpg?resize=700%2C466)
Ignoring your air filter
![](https://www.rd.com/wp-content/uploads/2018/07/02-12.jpg?resize=700%2C466)
Never cleaning fins and coils
![Climate control on office wall, selective focus](https://www.rd.com/wp-content/uploads/2018/07/10-Air-Conditioning-Mistakes-You-Can’t-Afford-to-Make-1.jpg?resize=700%2C466)
Not updating (or setting) your thermostat
A programmable thermostat is a must-have in today’s state of AC technology. Programmable thermostats allow you to set temperatures for various times throughout the day and automatically lower the temperature when you most need it to help you save money and manage your cooling without constantly hovering over the dial. Many advanced thermostats like Google’s Nest thermostat actually have learning capabilities, so the thermostat can shift to accommodate repeated schedules—not to mention allow you to change the temperature from an app. If you don’t have one of these programmable or smart thermostats, the time to upgrade is now! Save money and enjoy more accurate cooling with a simple thermostat replacement, especially if your current thermostat is a couple decades behind the times. Find out some tricks to keep your air conditioning costs down.
![Air compressor at the blockhouse or wood house.](https://www.rd.com/wp-content/uploads/2018/07/10-Air-Conditioning-Mistakes-You-Can’t-Afford-to-Make-2.jpg?resize=700%2C466)
Using the AC when no one is home
![The shower drain with tile floors](https://www.rd.com/wp-content/uploads/2018/07/10-Air-Conditioning-Mistakes-You-Can’t-Afford-to-Make-3.jpg?resize=700%2C466)
Not checking your drain
![Hand with remote control directed on air conditioner](https://www.rd.com/wp-content/uploads/2018/07/10-Air-Conditioning-Mistakes-You-Can’t-Afford-to-Make-4.jpg?resize=700%2C466)
Turning the temperature down too low
![Air compressor installation on pedestal.outdoor](https://www.rd.com/wp-content/uploads/2018/07/10-Air-Conditioning-Mistakes-You-Can’t-Afford-to-Make-5.jpg?resize=700%2C466)
Ignoring sizing requirements
![Repairman fixing air conditioner unit](https://www.rd.com/wp-content/uploads/2018/07/10-Air-Conditioning-Mistakes-You-Can’t-Afford-to-Make-6.jpg?resize=700%2C466)
Avoiding replacement
![Technician is checking air conditioner ,measuring equipment for filling air conditioners.](https://www.rd.com/wp-content/uploads/2018/07/10-Air-Conditioning-Mistakes-You-Can’t-Afford-to-Make-7.jpg?resize=700%2C466)