What is wrong with my central air?

Question

It started to freeze over. The line that goes from the outside fan to the unit in the attic, to a solid block inside the unit where the radiator looking deal is. It takes all night to cool the house down to 80! It was ice cold last month. I want to have an idea before I call a repair man so he won't try to cheat me.

Answer 1

You have a low freon charge or your filter/strainer is getting clogged, both of which will cause the freon to evaporate prematurely. Any repairman who doesn't check for leaks should be paid with a rubber check.

Answer 2

I am an HVAC tech and i can tell you the answer is not always "add refrigerant". The tech will check for a leak and if you have one, yes, you will need refrigerant. This you can do yourself. Get a spray bottle and put a strong concentration of liquid soap and water in it. Start spraying the joints as opposed to the straight parts. If there is a leak, bubbles will form. Then you can cut down on the time that the tech is there and therefore save maybe an hour labor.

The problem can also be user error. If you are running the A/C to acheive a meat locker effect, then no wonder your lines are icing up. If the return air is too cold, you will freeze your evaporator and the lines and the compressor. You keep freezing the compressor and you got trouble. Turn off the cooling and run the fan only to melt the ice and then set the thermostat to 72. If after you run it for a while and it doesnt cool, and ices up again, there is one more thing you can do before you call in a pro. Check your filter. If it's dirty, change it and see if it changes things.

You may have one or more of these causes going on. Check the things i told you about and if you dont find anything, call in a pro.

BTW if any tech tells you that you have to charge your system every year because it's routine, ask him to leave and call someone else.

Answer 3

Low air flow over the evaporator coil will cause it to ice up, as will excess cooling on the condensing side.
First thing to check is the thermostat. Is it set to a reasonable target, such as 72 degrees, or did someone push it to 55?
Next thing is to check the filter. Clean or replace if it is dirty.
Next step is to check the blower. Is it moving enough air?
Next step is to check the indoor coil (radiator looking thing in the cabinet). Is the side that the blower blows on clean? If not, GENTLY clean the coil with coil cleaner and a soft brush.
Next, does the outdoor unit run constantly, even when you've turned the thermostat temperature up higher than the room temperature?
If this doesn't help, contact a reputable repair company. Not all repairmen will cheat you. Look for a reputable company that guarantees their work. Yes, you will probobly pay ~ $200 for the visit, but your system will work properly afterwards.

Answer 4

Check the Filter. Then there are coils on the outside, check they not clogged. There are also coils on the inside check they not clogged (This may be in the attic). Make sure the fan inside works.
This important if you come to this point; Turn it on and see that it is running, turn the thermostat up until it turn off. Now, go outside and see if the compressor and/or fan is still running! If, it is then there is a Relay inside the unit outside and it is stuck, making the compressor run constant and freeze up. This all I know.
Then it have to be the Freon I guess. Which means Repairman.

Answer 5

It really sounds like a freon leak/problem. First check the ventilation and make sure nothing is blocking it. This sounds especially true if it just recently worked nice, and now not. Good luck! :)

Answer 6

Lack of proper refrigerant charge is most likely cause. Their is no such thing as a cheap central air repair.

Answer 7

You may have a leak in your line set or condenser.