Everyone’s typical woe during the summer is that their air conditioning won’t start! But what if you have the opposite problem? What do you do if your A/C won’t stop running?
You don’t want your A/C running continuously because it’s bad to have that constant strain on the system, and also because your bill — much like your cool air — will be shooting through the roof!
Now, if the weather is extremely hot, your A/C may need to run almost constantly to reach the temperature you want, but we are talking about when the temperature is in the 70s or 80s, and yet your A/C will never take a break. There are many possible causes, but it’s most likely a problem with the evaporator coil, which means you need a professional to come look at it!
A dirty or frozen evaporator coil can make it harder for your A/C to cool air, making it work harder all the time and never turn off.
You may be wondering, what exactly is an air conditioner’s evaporator coil? Well, the way an air conditioner works is through using refrigerant to transfer heat — in the case of A/C, transferring it from inside to outside! Inside the evaporator coil, the refrigerant is a liquid, and the warm air from inside your house passes over it. Since the refrigerant liquid has a low boiling point, this warm air, raked over the evaporator coil, is enough to turn the refrigerant from a liquid to a gas. That’s why it’s called the evaporator coil, because the refrigerant gets hot and evaporates.
Anyway, it transfers that heat inside your house away, and now that the refrigerant has absorbed the heat, a fan can blow the newly cool air into your home!
So that’s why a dirty evaporator coil can make it impossible for your house to cool, because then the refrigerant isn’t able to properly absorb your home’s heat. And an evaporator coil can also freeze, because if there isn’t enough warm air from your home to absorb (due to airflow problems), the coil gets too cold.
You would need a professional to determine whether the evaporator coil itself is the issue, or if it’s a symptom of an underlying problem. But either way, this is usually what’s at the heart of the problem when your air conditioner won’t turn off.