Home Airconditiong Frozen

[jabb]

I have a problem the Air Handler for my Central Air system that is located in the Basement is completley frozen. Anyone know what causes this and what need to be done to fix this

[willtel]

Low freon charge usually.

[stomachmonkey]

The freezing is caused by cold.

Let it melt.

Seriously, I have no clue.

Bump.

[krichard]

Low freon as stated above. You probably have a pinhole leak somewhere. Just went through the same thing and ended up replaceing the air handler since the leak was in the core.

[cmccuist]

Originally Posted by willtel

Low freon charge usually.

+1

You need to have it serviced. Usually adding a few pounds of R22 or whatever your system uses will fix it. But you also have to find the leak.

[willtel]

Until you get someone out turn the AC off but leave the fan running for a few hours to thaw it out. Once it thaws you can turn it back on and monitor it. A cool cloudy day or rain on the outside unit will make a low system freeze up.

[jabb]

How about Air Flow I had a problem withe the pump and removed the side cover off the Aid Handler can that cover being removed cause lack of Air flow and cause the handler to freeze up ???

[Shuie]

freon leak. Call a technician and get it serviced. If you don't already have a wet-dry vac, go get one now.

[Brian 162]

It's probably low on charge.
It could also be airflow related. Check the filter, loose belt (if applicable),or see if the coil is dirty. You may gain acess behind the metal cover with the sticker (from your photo). Or try to stick a mirror under the coil.

[75'930cab]

My buddy had the same problem. He called a AC tech and when he came out he charged him $89.00 to hose off his AC condenser! His condenser was clogged with leaves, grass, debris, etc..., so it was not cooling off the freon and restricting air flow!
I told my buddy I would of hosed it off for half price! lol

[fintstone]

low air flow is often the culprit...open all your vents and put in a clean filter. Run the fan with the compressor off until it thaws (It should not take long). It will likely be back to normal. happens to me once or twice a year when I get too agressive on closing vents in some of the rooms I don't use.

[cstreit]

Why would a low freon charge cause the evap to freeze up like that?

[idontknow]

a lack of liquid refrigerant in the line would cause the freon to flash over from liquid to gas sooner than usual and cause the whole coil to get a lot colder, sooner than it should.

A dirty coil or air filter could definitely cause that.

[mthomas58]

+1 on pinhole leak in the evaporator. Fix is evaporator replacement.

[Radioactive]

Change the filter.. Turn on the heater

[billybek]

Originally Posted by cstreit

Why would a low freon charge cause the evap to freeze up like that?

A low charge will as was already said flash from high pressure liquid (and gas mixed) to a low pressure saturated mixture after the expansion device (valve or capillary tube). Due to the lower operating pressure of a system short of refrigerant, the saturated temperature also drops. Under 60 psi with R-22 you end up treading close to the freezing mark.
As the system operates this way, a little ice will form where the refrigerant enters the evaporator. Over time it builds itself into a mini coil shaped igloo. Because the system is short of gas, the run time is longer so the igloo gets more and more time to build.
A quick way to check the charge in your home central a/c, after thawing, start it up and allow it to run for a while, grab onto the suction line. Should be cold. Grab onto the liquid line supplying the coil, should be warm to the touch, but not hot.
Short of gas? Do, or get someone to do a leak check with an electronic leak detector. It may be an easy fix. Another tip, look for oil on the system. If the oil is getting out, so is the refrigerant.

[T77911S]

Originally Posted by fintstone

low air flow is often the culprit...open all your vents and put in a clean filter. Run the fan with the compressor off until it thaws (It should not take long). It will likely be back to normal. happens to me once or twice a year when I get too agressive on closing vents in some of the rooms I don't use.

a good place to start. may save you a call. you can put your Tstat to heat and it will defrost faster.

if it does it again, perhaps a shot of 22(?). that A coil is easy to get to and the unit looks in good shape. just replace the A coil if it is leaking. should not be more than a few hundred.

there is also a chance the orifice tube is clogged.

put gages on it once it defrosts.

[onewhippedpuppy]

Before calling out a tech for a minimum of $100, do the following.

1. Defrost as described
2. Change your filter. Be careful of filter choice, on my older unit the new high filtration/low dust filters really seem to reduce airflow. I find the cheapo blue fiberglass ones work best for my antique.
3. Buy a bottle of A/C coil cleaner (good hardware store or HVAC house - not Lowes or HD)
4. Clean your a-coil and condenser unit. Process depends on your cleaning product, most require soaking spray on the fins, a few minutes to soak, then rinse with water.

That will insure maximum airflow over the coil. If it's still freezing up then call your A/C guy. As a bonus a clean coil, clean condenser, and new filter will insure that your system is operating at its maximum potential.

[jabb]

Thanks for all the great suggestions..... The filters are pretty clean but I cleaned them anyways...... They are the Metal Mesh with the Electrostat thing. I will clean the condensor outside and followup on a few of the other suggestions its been a while since it was serviced so maybe it is low on Freon...... It took a few hours but it is all defrosted..... Thanks for the help.

[MBAtarga]

If/when you use the A/C coil cleaner, rinse off the coil by spraying from the inside of the condensor. Spraying from the outside of the condensor will force dirt further into the coil fins and can make the coil operation worse.