it's definitely another. We were beyond thrilled when we had an estimate for our A/C replacement that was $400 less than our initial estimate and could be done the same day. As soon as it was installed, the weather took a turn for the better and we didn't have to use it for a few days. We're scheduled to have it tied into the security system on Thursday. In the meantime, poor Tom has been sleeping downstairs. The idea is that he'd wake up to any unusual noises happening in the yard, but I still check on the condensers from an upstairs window several times a night.
After the brief respite from the unbearable heat and humidity, it came back in full force all at once. We enjoyed a full day of lovely climate-controlled bliss. Until...Tom noticed a puddle of water downstairs. The furnace overflow pan was, well, overflowing and dripped from the attic to the second floor. It in turn soaked through the floor upstairs and dripped into a puddle in the kitchen. Tom investigated and found a whole slew of problems with the air handler setup. The two biggies:
1. The overflow pan wasn't draining at all. Since the plastic pan underneath is actually the secondary overflow, that meant the primary overflow wasn't draining, either.
2. There was no filter in the furnace. The drywall guys had the system running while they were sanding, so the coils are probably clogged with a superfine particulate. A homeowner should be able to vacuum the outside of the coils with a brush attachment, but something as fine as drywall dust will clog the inside of the coils, requiring professional assistance (to remove the coils, the refrigerant has to be drained, and it's easy to damage the thin aluminum fins inside the coil).
The secondary pan wasn't draining because the PVC pipe that carries the water outside was not sloped properly. That's easily fixed with a couple of dollars worth of supplies from Lowe's.
The part that really boggles the mind is why the primary pan wasn't draining. There are several sets of inlets where you are supposed to be able to connect the drain pipes. They look like this: