What to Do if Your Air Conditioner is Freezing Up
There's nothing better than coming home after a long, hot day, and finding that the Air Conditioner is Freezing Up and hasn't been keeping the home cooled off as you expected! You can sense the sarcasm... right?
Truth is, that exact thing has just happened to many of you reading this page, and by now, you could care less about sarcasm, and simply want to know what you can do to fix the problem!
Why Does the AC Coil Freeze Up?
The simple answer is that the AC Coil was not able to evenly transfer the cold temps of the freon in the evaporator coil, to the warm air of your home... and simply froze. Most of the time, frozen ac coils are a result of an air flow issue, however there are other reasons as well.
You can diagnose a few small things, to see if its something you can correct yourself, or whether you need to call a local HVAC Contractor! Most (I have no scientific number, but would estimate 95% or higher) air conditioner freezing is caused by poor airflow, aka dirty filters!
What to Do When You Have a Frozen AC Coil
The first thing you want to do when you find your air conditioner freezing up, is determine what is working, and what's not!
- Is the Outside Condensing Unit Running? (It should be)
- Is the Indoor Fan Unit (Air handler or Gas Furnace) Blowing? (It should be also)
- If the fan is not blowing inside your air handler unit, you probably found the problem, well... sort of. You can inspect the wires and check your breaker to make sure the unit is powered on, but aside from a bit of basic troubleshooting, the rest is best left to a technician with the right tools! If you have those tools already, feel free to go here for further fan motor troubleshooting.
- If the air handler fan IS blowing, then you likely have an airflow issue or low refrigerant levels! One of these is an easy fix.. the other takes a technician, a jug of freon and a leak detector kit.
Start with what You Might be Able to Fix - Air Flow Issues!
- Check and replace the return air filters! These 1-inch throw away filters that are often overlooked, are the most common cause of the air conditioner freezing up!
- Check for a Secondary, or whole house filter, usually a 2-4 inch thick filter located right at the furnace or air handler! (Not everyone has one of these)
- Visually inspect the evaporator coil in the unit, it is plugged with dust or bypass build up on either side of the coil? (You may need to wait for it to thaw a bit)
- Next, take a quick look at the ductwork in your attic, basement, crawlspace, wherever it may be. Has it been crushed or pinched n a way that would prevent air from flowing freely? If so, correct it!
After you have checked for, and corrected any air flow restrictions you may have found. Power the unit on again and see if the airflow issue is corrected. If so, you are done!
What if it's Low on Freon?
If your airflow is fine and the fan motor is working properly, the next place to look, is the freon levels of the unit. Being just a 1-2 pounds low can have a negative effect on the system and contribute to the coil freezing.
This is also where it starts to become too much for a handyman to handle on their own, and its time to call in a pro! The next logical questions most homeowners have, is How Much Does Freon Cost, which can be found in the repair cost section of the 2010 Air Conditioner Repair Cost page.