So Maybe I'm an Idiot

Not positive about it, though.

Saturday was a very hot day. It got slightly over 100, according to our thermometer. Well, round abouts 5:00, I started to notice that it was getting noticeably warmer inside than it had been all day. This despite the air conditioner running non-stop. I thought this odd. I investigated, as that's what men do.

I put my hand in front of a few registers, and the air coming out was not noticeably cooler than the general ambient temperature of the room. So I went outside and put my hand in the airflow coming off the compressor. Normally, this is quite hot, but like the registers inside, it did not appear to be any warmer than the outside air.

Hmm.

I checked the hoses running in and out of the compressor. The big cold line was quite cold, but the small hot return line was not hot at all.

I saw this as a bad sign. The AC is producing cold, but the cold is not absorbing the heat of the house.

I had memories of the conversation I had with the previous owner of the house a couple days after we had moved in and the shower had begun leaking through the dining room ceiling (leading to the $12k shower fiasco), and how she had mentioned kind of offhand how she used the same company to repair the shower that she used to repair the HVAC and how the AC had cost them $3k in repairs just months earlier. And I figured if that company fixed AC's as well as they fixed showers, I was completely e-f-f-e-d, f'd.

But I continued to investigate, as that's what men do.

The lack of heat exchange led me to suspect a problem with perhaps either the heat exchanger or the airflow. The airflow being easier to check, I pulled out the filter, and it was a very dirty mess. So I charged out to Ace to buy a replacement. Of course, Ace was closed.

When I got back home, I decided to see if I could check the heat exchanger. I opened up the furnace and looked up. I could not see the heat exchanger. I could see where it was supposed to be, but I could not see it. All I could see was a big block of ice.

Uh oh.

I thought for a bit what could cause a heat exchanger to ice over. Our heat wave was only 2 days old, and we had had one for two weeks last year without an icing problem.

Oh, sh!t. I forgot to turn off the humidifier in the spring. I've never owned a humidifier before. But there it was, trying to maintain 40% relative humidity inside the furnace. I turned it off.

We've now made it about 52 hours without icing.