My upstairs unit was blowing hot about 3 weeks ago. I cut it off for a few hours then back on. Ran fine till today. Blowing hot this morning and again cut it off. Cut it back on and worked fine for about an hr then back hot. What gives?

Low freon

I would have to say Freon leak. Or filters may need changing.

I was thinking that or the compressor.

See if you can feel air moving in the return when it quits. May be low on freon and freezing up. Cant cool if it can't move air.

You don't need A/C anyway. Don't you know it is more dangerous than Isis??

Need more specifics. Is the outdoor unit running (fan and compressor) when it was blowing warm inside?

one of the two or both isn't running if it's just circulating room temp air inside. If the out door fan is running, grab the insulated lines copper and see if it's cold, that's the quickest was to see if the compressor is running if u can't hear it. I've had a lot of compressors overheating and shutting off on overload lately due to stopped up coils outside.

The outdoor fan keeps blowing. The indoor fan blows hot air. No change in the pressure coming out of the vents just the temp. Just don't know how a freak incident a month ago that cleared up is back now.

can u tell if the compressor is running?

Not sure how to tell.

the bigger copper line coming from the compressor will not be cold . the air blowing out of the fan will feel cooler than the air around you .

They are cold and sweating. So the compressor should be fine.

Incorrect. The larger line which is insulated will be much colder. Also, the air coming out of the top should be hotter then the outdoor ambient temperature, heat transfer taking place.

Megatrondiablo, if it's cold and sweating the compressor is running. If u have a thermometer measure the air temp coming out of the supply vent upstairs. It should be 16-21 degrees cooler than the room temperature.

but are they that way when it is blowing hot air

i guess i should have added "is not working if " . lol

Travis it's blowing cold now. It's just a hit and miss problem. I'm gonna spray the outside coils out tomorrow.

Ahh,I gotcha. Lol

Yea I'd spray the coil out real good. if it starts blowing warm again, grab that line and see if it's cold or just ambient temp. Def. sounds like a compressor is being intermittent. Hopefully just needs a good cleaning to get things working good for you.

i'm gonna bet low on freon

I'm going with contactor getting weak.

If so, I'm betting it has a stopped up condenser coil keeping the suction pressure just above the freezing point, typically if the only problem is low charge, first symptom is freezing up vs overheating compressor shutting off.

who knows, it could be a number of other things as well. I'm done thinking for the night I'm going to bed

but the fan would be off too

yep . i have to clean all my coils (inside and out) ever two years here , they get messy fast .

2.5 lbs low

Older system?

Time to find the leak.

Yep it was new in 88. Gonna do a leak check soon.