2 Problems with my home A/C unit

We just moved into the house last fall and we have a whole house fan so just a few days ago was the first time we have HAD to turn on the A/C. It didn’t cool the house at all after 2 days of running. So I go out to look at the unit itself and the copper(?) tube going to the house is covered in a 1/4" of ice. Also there is basically NO air coming out of any of the vents. A very slight breeze. If I touch the duct work down by the furnace its very cold. But like I said, basically nothing comes out at the vents. Any ideas?

There should be two lines from the compressor(outside) to the evaporator(inside) one will be bare and probably hot to the touch, the other should be covered with insulation and should be cold, if it is iced up it is a good sign you are low on refrigerant.
As for the airflow, probably an obstruction in the venting or maybe you need to switch a panel in the ducting when switching between heating and cooling.

Sounds like you have a damper in the duct system that’s stuck shut. There may even be more than one. Check around your visible ductwork and look for something attached to the duct with wires coming out of it. That’ll be the damper. some can be manually operated, but most are solely electrical. If you have a meter, you caqn check and see if the damper motor is getting juice when the system is runing. If so the motor is bad, if not the problem is elsewhere.

I have absolutely no experience with A/Cs other than installing a couple window units, but it sounds like the compressor/heat pump/whatever is working but the fan/s aren’t or the filter is very dirty.

Find the air filter and check that first. If it is completely clogged then the fan won’t have any air to move. A new filter may solve your problem. If it doesn’t the fan motor may be burned out. There may be a reset switch on/near the motor as well.

Be careful of electricity and spinning blades. Good luck.

Air filter, maybe clogged evaporator coil (the thing that the copper lines go to inside the house. The air is cooled when pulled past this) if clogged clean it, compressor maybe low on freon.

I assume Q.E.D. is talking about the same thing, but look along the lenght of the duct work and check for any little “knobs” for lack of a better word. And see if anything happens if you turn them 90 degrees. You’ll know what I’m talking about when you see them.

what if (as in my case) I have good airflow, but the air coming out is room temp.? I have an outside central ac unit, and it sounds like it is functioning fine (i.e., it kicks on when it is supposed to), but the air never gets cool. What could be my problem there? If I am out of refrigerant, what can I expect to pay to put more in?

Maybe the two problems are related?

I had a similar problem with my new apartment A/C.

The pipe that carries the evaporated freon (isn’t this called the low side?) back to the compressor was COVERED in ice…all the insullation had broken off. Likewise I was getting no air through the vents, when, just a day earlier, I was sure the air was working fine.

SOO, being the investigative sort, I pulled all the panels off the front of my unit and found the reason I was getting no flow. The ice that was on the tube was also ALL OVER the evaporator. I mean, we’re talking caked on. There was no way air could get through because ice was blocking any air trying to get through the evaporator. So I powered down the unit, waited for everything to melt (mopped up the resulting mess) and powered back up and everything was fine.

Now I will point out that someone (cough, no names but his initials are M.E.) had pushed the thermostat down as far as it would go, and left the unit cooling for 2 days…which is why I had the ice problem, I believe.

After leaving it on a more normal temperature that allows the unit to cycle, I haven’t had the problem at all.

Sooo…I don’t believe MY problem is related to freon. BUT if your system is low on freon, which causes ice-formaton on the pipe, mayhaps the ice is also forming on the evaporator, causing the blockage you’re describing.