Thursday, July 21, 2016

In which I do my yearly home air conditioner repair...

It's becoming tradition, I guess. Every summer since 2013, I've had to Do Something to the house air conditioner.

I don't mind being the designated "Do It Myself" guy. It does save money, but more importantly it gives me a challenge. Ever since Aorta Day 6 years ago, I've been reduced to a couple of states:


I wish I could say I've made huge strides in recovery, but I haven't. I get winded walking from my bedroom to the bathroom. Last year's procedures to line the entire length of my aorta with stents didn't improve my stamina.

This means that the "Do It Myself" stuff doesn't go as quickly. Actually, if I can't put a chair next to it, I'm screwed.

So here's me Monday afternoon (7/18), already blown out from making a grocery store run with an over-100-degree heat index. I get home and feel more and more uncomfortable, thinking it's my meds or whatever. Then I realize the air conditioner's not blowing.

It's obvious right off that it's not the "usual" problem, which has been ants getting themselves electrocuted & burned to ash by crawling onto the contacts of the big power relay on the outside air unit. That thing's running 220 volts and loads of current. Bugs are like republicans, though--they will not listen to reason and cannot be educated out of their determination to fuck with things they don't understand.

I don't bother with republicans (they get zapped, they're on their own); but I've gotten good at cleaning bug husks off the relay contacts.

This time, though, the outside unit was fine. No fan indoors, though. I did my usual thing of going to the Internet and finding schematics, learning about the air handler (indoor unit), and putting together a short list of stuff to look at.

This took all of the next day, Tuesday. It was miserable enough in my bedroom that I went and bought a second fan. I could have just put the little window air conditioner in and slept and researched in comfort that night. I ended up doing it Tuesday afternoon anyway. I pretty much had to--one of my medical problems since Aorta Day is that I can't take much heat.

Tuesday ended with me finally getting my tools in from the car and opening the air handler's cabinet.

I slept comfortably...but the rest of the house was somewhere over 90. My nephew's room at the opposite end of the house from mine was sweltering. He doesn't have a window AC unit.

I slept as much as I could, trying to recharge from the previous day's overheating. I didn't exactly bounce out of bed Wednesday morning, but I got up around 11am and got to work. Then I realized I needed my voltmeter...and wasted a few hours looking for the damn thing. It was in my car.

So now it's almost 3pm and I get the tester testing...without going into all sorts of detail let's just say I had it narrowed to 2 components. One tested good, so I started calling AC suppliers looking for the other component. Every single one turned out to be a wholesale-only shop. Two of them would sell to me as a residential customer, but there wouldn't be any warranty or return on the part.

The first one wanted almost $40, and I was ready to go for it, but it was 3:50pm and they closed at four. Crap.

By the time I found the second supplier willing to sell to me, it was nearly 3:10pm. This guy wanted $20 and would close at 4:30.

I got my nephew to drive; he's a bit more aggressive in traffic and we needed that advantage. Made it, got the part, got back, and I plugged the thing in.

Nothing. No fan.

I poked at the thermostat's buttons...and the fan came on. Hah!

The AC system ran all night, nearly 12 hours. I kept an ear open, but knew it was going to take a while for it to bring the house down to 73. It finally clicked off around 4:30 Thursday.

We all slept comfortably.

Thursday morning saw me checking the system. I'm naturally suspicious of any "success" in fixing stuff. Sure as hell, the fan wasn't running and it was almost 80.

Crap! See? Never that simple.

I poked at the thermostat, since that had made it go the day before. Nothin' doin'. But the thermostat was telling me the fan was on.

I popped out the thermostat to try resetting it.


There was a big, brown, recently-dead roach jammed into the thermostat box, belly pressed against the circuit board.

I tried shaking it out, but it was stuck. I tried prying it out and tore its ass off. Its guts and the remnants of its last meals came out, too, and introduced me to a nauseating, garlicky stink from its fermented food.

I ended up taking the thermostat apart to get that fucker out. Again, without all the details, I cleaned up the board, traced out the circuit board, and found a spot where the dead roach had apparently shorted the one freaking spot on the board that connected to the wire that controlled the fan. I've never seen anything like it before--there was enough moisture in the bug's body for it to electrocute itself in the low-voltage (24 volts!) side of the system. AND it provided enough of a circuit itself to cause damage to the board--that one component lead was eroded all the way to the foil solder pad, the solder was nearly oxidized away, and the circuit trace itself was damaged. Huh.

I cleaned some more, soldered a repair, put everything back together, and put the thermostat back in place. AC system fired up, fan came on.

Turns out I probably didn't need that controller board I bought, but it's still one less thing to go wrong later--and it was only $20. I need to bug-proof the back of the thermostat.

Now we see whether the fix of the fix is fixed.

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