5+ year old Central A/C Unit recently is "freezing" up; Coils as well as Compressor freezes up.?
Question:The A/C Unit is one whole unit (not two seperate sections).
I've cleaned the filter and coils but, the unit still freezes up after about 3 hours.
I then have to shut the unit off for at least 3 hours so it defrosts.
It's been very hot in our area (about 93 degrees on average) the last week or so and the unit constantly runs (except at night when the temps fall to the lower 80's).
Any ideas why it recently started freezing up?
It is caused by a lack of airflow through your house. I had an AC unit on a flight simulator that kept freezing up so we had to put an extra vent to allow for more airflow to balance the cooling. That fixed it!
I see this problem a lot,since you've already said that you have cleaned the coils,I think you may have a small leak.
My memory is that if the freon pressure falls too far below the expected, then they will both freeze up.
In general, an A/C system freezes up if it is over-sized for the space.
So, if, as you say, the A/C is running all the time, then is not over-sized, and the freon is probably not circulating properly. There are some other features, like a "hot gas bypass" which may have a faulty or sticking control valve. These features as a group, improve efficiency and reduce icing.
This is the kind of stuff you pay someone to look at. Something you might try to do is go around the house and opening the flow control dampers on all of the discharge diffusers. These come in two primary forms: on the diffuser itself, there is a lever or thumb-turn which opens and closes the damper. Other systems have this damper system behind the walls, up in the ductwork, shown as a lever on the side of individual ducts. Almost all system builders set the lever to match the damper position: when the lever is pointed parallel to the duct's flow, then it is full open. Perpendicular means totally shut. Make sure you don't miss any.
By opening all of them, you drive the maximum air through the coils, so their opportunity to freeze diminishes.
If this works, then you can slowly trim a little here and there to reduce cooling in some areas, but do not modify with the expectation of forcing all of the air into one space to keep it cold by choking-off the remainder of the house.
you have whats called a "package unit" . Its a 5 ton unit so it may be belt driven, check the indoor blower motor and see if it is in fact belt driven, the belt may be worn and slipping causing a "low load condition". you have cleaned the coils and changed the filter which is good. Beyond that have a service company check it out, they will have to check superheat and subcooling along with pressures to see what is actually happening with this unit.
Have you had it 'charged" lately.alot of good answers here,..but also as general maintenence have you had it charged with a boost of freon lately? What some people don't know is that too much freon for a system will also cause one to freeze..and check for ants under the cover near all of the electrical contacts etc... ants are attracted to the magnetic field of an ac and will nest near the contacts..
Unit`s thermostat seems not working properly.please call
ref rigeration mechanic to help you.
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