Ice forming on Coil inside AC?

Question

Hello, I had a problem with my AC. At one point, air was blowing, but it wasn't cold.

I then replaced the filter with a new one. Cold air then started coming out of the vents after I did this.

I did notice that, that night, it got pretty cold, but I still had the A/C on. SO the next morning, I checked the air coming out of the vents, and it was still cold. I then looked at the unit inside, and I noticed that there was ice formed on the coil.

What do you think the problem is here? Do you think some ice formed because it was cold outside?

Some notes is, I live on a 3 level townhouse condo, where I own the top 2nd and third floor. The ac unit is on the 3rd floor, and I have very little access to it. I know that the outer coils should be cleaned, but I can't really do it. I know, it sounds kinda dumb.

Any help would be well appreciated.

Thanks

Answer 1

The outdoor unit may need a cleaning but would not cause ice to form.

More than likely it is low on refrigerant.

Have a tech check it out.

Answer 2

No the ice is not normal. and the ice is actually forming at the indoor coil and making its way to you outside unit. I'm guessing the cool air that you are feeling is from the coil being iced up on the inside which is not normal...have an a/c tech come out check the freon..but be sure that he looks to see if the indoor coil is clean before adding any freon.

Answer 3

HVAC Tech.:  It is NOT normal for ice to form on the evaporator coil. If the system is working as designed that coil will be at about 40 degrees, well above freezing,frost or ice. Restricted air flow will cause icing, your dirty filter could have caused it and you didn't notice the ice until later. Also if dirt had gotten past the filter it could partically block the air flow,preventing some heat pick-up and allowing freezing. A low charge could also account for the icing.

Answer 4

some ice forming on the condensing coil is normal. Unit should cycle to minimize ice formation

Answer 5

If your filter was really dirty, this was the cause of the problem. You need to turn off the cooling at the thermostat, and set the fan switch to on. Let the fan run for at least six hours. Keep checking your furnace for water on the floor, ice may have grown outside the drain pan, and may cause a problem. Restart your unit, and see if ice starts to form again. If it does, then it may indicate a low charge condition that can only be repaired by a technician. Good luck.

Answer 6

When dealing with major appliances its best to have a professional service person look at it. DIY may be a quick cheap fix, but if you make a mistake it could be expensive!

A little ice or frost doesn't sound unusual, since there is a lot of freon or coolant in the unit cooling the air. Its probably a little condensation on the unit that froze.