Just a simple test.
I'm assuming this is a 'central air conditioner' and not a window unit.

By not working I also assume it's not cooling.
Beside the issue of adequate cooling gas, a common reason for intermittent
cooling is a dirty 'A' coil in the plenum.
If you have an access panel, that you can open and find the A coil 'iced'
up, that means inadequate air is passing through usually due to dirt, dog
hair, dust clogging the fins.

A qualified service man will use compressed air and vacuum to clean it.


wrote in message
ups.com...
Hi there

My central air unit will work one day, then not another. Or it will
work for a while then stop. By this i mean air is blowing out of the
the vents, but not cold air. Sometimes it does work however. I have
a clean filter and i have tried it on auto and on fan with the same
result. I don't understand how it can work one day and not work
another. ANYONE know why???

Thank You for your time

Sonia