Air Conditioner not working

[davef]

Two days ago my AC stoped putting out cold air. I left it on all day yesterday and it seemed to have no affect on the house temperature.
The unit is from 1996.


Troubleshooting.
Air is coming out the ducts, but it is not cold, it is about room temperature, the volume of air feels like it might be less than normal as well, but I could be imagining that.

The thermostat seems to be working. When I turn the AC on I hear both the fan and the unit outside come on. When I turn it off. however the Unit outside turns off but the fan in the garage continues to run for a while. I dont remember it doing that before. The fan itself seems to work fine.

I am going to take the cover off the unit this afternoon and clean the coils, But this sounds like a refrigerant problem to me. either leaking refrigerant, or a hydrolocked AC compressor.
Any other ideas on things I can check?

[wizlem]

I'm not an expert but I though the blower should always run a little while after the furnace/compressor turns off to pull any residual heat/cold out of the system.

Since its not obvious since the compressor seems to come on, I'd first check to make sure your coils aren't freezing up and that they are cooling down. If they're freezing up and aren't clogged with dust you have a refrigerant problem or your AC unit is too large for the air flow.

[davef]

Thanks, Ill Check that.

[zolotiyeruki]

I think you've got two potential problems:
1) You're low on refrigerant.  It's quite likely, given the age of the A/C unit, and it will cause the symptoms you describe--air not coming out cold, and reduced airflow.  It ices up your evaporator coil (inside your air handler).
2) Something is causing your A/C to short-cycle.  The "something" may be the low refrigerant pressure (just happened to us a couple months back), or someone monkeying with the thermostat in humid weather.  This will show the same symptoms--iced up evaporator leading to reduced flow and higher temperatures.

If you have a capable thermostat, set it to run the blower all the time, but leave the heat/cool setting to "off", so the system just circulates air.  That will help melt the built-up ice and at least restore the air flow.

[phred]

ac'coolth' stopped all of a sudden?  Please check the starting capacitor attached to the motor in your outside part of the ac.  You may need a multimeter to do this (after cutting the house power).  If the capacitor can has bulges it's history

[Roots&Wings]

When my AC stopped cooling suddenly, it was a blown capacitor due to storm/lightning power surge.  Relatively quick easy fix (by an HVAC company since I'm not at all handy and needed it working again fast in the 90+ degree Florida summer).

[davef]

Thanks for the replies guys.
Saturday I pulled off the access panel to find one side of the coils filled with 20 years worth of cottonwood seeds. Add to that, there was a thin layer of moss/mold on the leuvers and fan blades. I proceded to spens the next 4 hours taking the entire theing apart and pressure washing each piece and then shop vaced out all of the coils. I put it all back together and it works great! thats a few hundred dollars saved im sure! Not to mention I'm sure it wont hurt the electric bill.

[zolotiyeruki]

Nicely done!  Yeah, that would have been a good $150 for a service call, and you'll save a boatload by having a cleaned-out system.

[HawkeyeNFO]

VICTORY!  Saved money, and kept the salesman/technician outta your property.  Who knows what they might have tried to sell.

[jordand1986]

Good to hear the problem is resolved. I love when you can fix something yourself and avoid those service charges.

[jmusic]

VICTORY!  Saved money, and kept the salesman/technician outta your property.  Who knows what they might have tried to sell.

True that.  Makes me wonder how many systems get replaced over what the tech knows is an easy fix...

[Bob W]

Nicely done!   

My AC stopped for some reason a few years ago.   I didn't bother calling the HVAC guy for a couple of years though.   It was two of the hottest summers ever to hit Missouri and my car AC didn't work as well.    Many, many, humid days over 100.  (this was well before MMM)

We slept in the nude with a fan directly on us.

Funny at the time (me in my early 50s) this didn't seem like much of an inconvenience.   Even drove 800 miles in 100 degree heat with no AC.    (did this for four summers in the car)

Fast forward 2 years and I get peeved when I arrive home if the house is 74 instead of 72.

So the correct answer appears to be.  When the AC fails.  Leave it off for a couple of years!

MMM wrote about the body adapting.  I concur with that.   We even camped in tents for 2 weeks of 100+ temps.    All the RVers stayed in their rolling palaces most all day, while we cooled ourselves in the shade and the 85 degree clear lake water.   The beer seemed to  help when it was very cold as well.

[guitar_stitch]

The body gets used to being chilled much quicker than being heated....  I found that out after fixing the AC in my pickup that I use for hauling music gear for my band.