Thursday, June 25, 2015

Re-debugging my HVAC

A few weeks ago I posted about my air conditioning woes, that in the end were due to ants infiltrating my AC relay.

I went out of town for a few days recently, and returned home on a 95 degree day to find that my compressor was not running and my 2nd floor was a steamy 93 degrees! The thermostat indicated that it had been running for at least the past 36 hours straight.

I immediately examined the back of my compressor housing and found it covered with ants. Once I had the access panel that covered the relay off, I confirmed that the 3 week old relay was indeed no longer conducting 240V mains power, even though the solenoid in the relay was powered and engaged. Freakin ants!

Apparently 3 week's worth of ant biomass @240 Volts

I had to act fast, it was around 2 in the afternoon, and the parts store, which was at least 1/2 hours away, probably closer to an hour in rush hour, closed at 5. I wasn't about to give up on the part so easily. Uncharacteristically of me, I had thrown out the receipt for the relay, so I'd have to buy a new one. I wanted to see if I could get the existing realy working again. I got a can of compressed air, some isopropyl alcohol, q-tips and fine grit sandpaper. The contacts had a heavy coating of petrified caramelized ant biomass. I was able to remove 95% of it, and my multimeter confirmed reliable conduction through the relay.

With about an hour to spare, I got the relay back in, flipped the breaker, and the compressor purred back to life. I think proceeded to wage chemical warfare on the 6 legged minions wrecking my day and my wallet. I had assumed that the first time was a fluke, or possibly a build up of ant carcasses over time. The second incident made it clear it was all out war. Fool me twice, shame on me.

My second floor cooled about 1.5-2 degrees fahrenheit an hour (I think it did hit around 100F outside later in the day), so by the late evening it was finally quite comfortable again.


1 comment:

  1. Last year I had lots of large mounds of fire ants and other types. I poured the fire ant killer granules on all the mounds and this year have very few mounds. I know some people try to discourage killing the non-fire ants as being beneficial ants.


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