Saturday, August 3, 2013

The Most Important Part of Repairing Something Yourself... knowing when to call in the experts. Our 11-year-old heat pump stopped pumping two weeks ago. Since I'm the guy with tools, people are looking at me to do something about it.

Nuh-uh. I understand the basics behind an air conditioner system, but the 220 volts of people-killing AC powering the thing scared me enough that I wasn't about to do anything deeper than pick up the phone and call in an expert.

That was easy, but there was a big problem: All four of us in the house are on Disability and this close to the end of the month we couldn't even pool enough money together to pay just for the service call, let alone any parts or repairs. We'd have to wait for the beginning of August.

I felt pretty shitty, having the only room in the house with a working air conditioner. I put a window unit in and shut off the house vent in 2011 because everyone else in the house is a smoker. With the house air down, leaving my room was like walking into a wall of heat and humidity. We had all the windows open, but the wind never seemed to blow in. Ninety degrees, all night long. On cooler nights, it dropped to 89.

After a few days of that, I did my usual thing, hitting Google and trying to figure out why the system wasn't working. I started poking at the controls, trying to make the system start...compressor and outside fan would "bump" but not run. I could hear the contactor relay clacking on and off. Then...nothing.

After watching videos and reading dozens of websites and looking over the wiring diagrams for our system, I decided, "hell with it--I'll give it a try." All the troubleshooting guides and pro advice pointed to a bad capacitor in the outdoor unit.

I was still paranoid about those high voltages, though. I double- and triple-checked the breakers and cutoffs, made sure I understood how to discharge the capacitors, checked for voltage even after unplugging stuff, and even threw together a capacitor checker using my old RadioShack "75 In One Electronic Project Lab" kit.

Pretty proud of that one. I based mine on this one by Lance Summers. Had to modify it a little (the kit didn't have the right values on some parts), but by this past Tuesday evening it was ready. Getting to the capacitor was easy. No dramatic sparks when I shorted it to drain any juice it might still be holding.

It tested "good," as far as my knocked-together tester was concerned. Dammit. But this didn't mean the cap is really good, just that it's still kind of working. I ran out, got my multimeter, and checked it again. One side (Compressor) good, other side bad (Fan). Good! I ran out and got a new one. Twenty bucks!

Hooked it up.

Smoke test! Compressor and outside fan "bumped," contactor clacked...and nothing. Dammit. At least there wasn't an explosion or smoke. Everything was exactly as it had been and I was down $20.

Back to the Google, more schematic study, and I started looking at that contactor. Its contacts weren't moving when the thermostat triggered it. They seemed frozen when I tried moving them manually. Unplugged the power, safed the new cap, and pulled the contactor....

Be careful when you're trying to pop the connectors off. One of them was holding on too tight and I kind of...broke...the terminal off the side of the thing. Dammit. Brought the contactor and its broken-off piece indoors, tried to save it, and failed. Still, it needed replacing even without my breaking it. The contacts were pretty badly pitted and hadn't been moving properly.

Had to wait for Friday morning (payday!). Back to the store, $19 for a new contactor. Got home, gathered my tools, went to work...

The two screw terminals for the power wires didn't fit the new part.

Screw going back to the store. I whipped out the Dremel tool and a grinding bit and started carving Bakelite off of the thing until I'd hogged out enough space for the terminals.

Back out, hook it up (and check a dozen times to make sure all the wires are in the right place), check it yet again, and hook up the power.

No explosion, no fire, so far...switch the system on...

Compressor and fan "bumped," new contactor clacks...and nothing.

This was that point: acknowledge defeat and call in the experts. I'd gone as far as I could. By this point I was thinking it could be a bad motor, something grounded, bad compressor...all more expensive and more involved than I was comfortable with.

Guy comes out, pokes around the indoor unit first. Finds a bad capacitor and swaps in a new one ($30, but now the indoor fan runs at full power). Pokes around the outdoor unit. Nothing wrong out there (he didn't criticize my work, at least). I could hear the compressor come on and STAY on (so the outdoor stuff is fine...I didn't screw it up!). Several minutes of tinkering and testing. He replaces the thermostat ($65). The system comes alive, running much better than before. $190.00 for all his work and parts. I was expecting much worse.

The cap and contactor I put in were money well spent (I wonder how much the A/C guy would have charged to replace those?) and I'm feeling pretty damn proud of myself.

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