It has become a rite of Spring. Mowing the lawn for the first time. Watching the songbirds visit the feeders, court, and nest. Seeing the blooms turn the drab of Winter into the beautiful bounty of Spring.
And fixing the M&%XXBerk$#'ing heat pump.
You see, every Spring brings the emergence of a veritable army of bugs, spiders, and lizards. Many of these creatures enjoy taking shelter within the not-overly-secure access cover on the outdoor unit. Many years ago, I looked over the shoulder of a repair tech, as he dug the carbonized remains of a spider out of the contactor in the unit. Little did I realize at the time, this is not a rare occurrence. In fact, it's almost a certainty.
Each Spring, I put my newfound knowledge to good use, deducing that when the thermostat is calling for cooling but none is to be had, I should look for the zapped remains of unfortunate bugs, usually earwigs, keeping current from flowing through the contactor. At well over $100 per service visit, I figure my knowledge has saved me close to $1000 by now.
Each time, this would fix the problem, but the condition of the contacts in my contactor reached a point--pitted and blackened-- where they would just not carry the current required to start the compressor. This year, I replaced the contactor--ordered online for the princely sum of 14 dollars. Install is straightforward. Much like spark plug wires, I removed wires one at a time from the old contactor, and attached them to the new one. I will post up pictures of the old contacts--they were beyond spent. Fortunately, the contacts in the new contactor are actually under a cover, which should go a long way to preventing this problem in the future.
Just don't forget to pull the electrical service disconnect!
11GTCS
Reader
5/6/20 4:14 p.m.
X 2 on checking to see if anyone is living in the control box / contactor before powering up for the season. I found the remains of a small garter snake (!) in one of mine once. Got himself between L1 and ground, didn't work out too well for the poor guy.
Pro tips: The combination start and run capacitor (or capacitors depending on the unit and manufacturer) have a life span especially in areas where there are long periods of sub freezing weather. If they show any signs of bulging either on the top (most common) or the sides and your compressor and condenser fan won't start it's worth the $20.00 bucks or less to try swapping out the capacitor before calling the tech.
Again, double check power is off and always short the cap to ground with a screwdriver to discharge them AFTER shutting off the power. Take a cell phone picture of the wiring before disconnecting to be sure you get the wires back in the correct places. Check any screwed on power connections (usually on the contactor) to be sure they're tight, loose connections will create resistance and heat. Burned / pitted contacts in a contactor are visual evidence that it's time to change the contactor.
While you have the power off give the condenser coil a rinse with a hose to remove any pollen or dirt. Keep the shrubs and grass away from the condensing unit for good airflow. Replace the air filter on the air handler and flush out the condensate drain line while you're at it.
I got 24 years out of a pair of Carrier condensing units by doing basic maintenance, they were still running when I pulled them out but were changed due to renovations at the house and R 22 refrigerant. Basic common sense PM will save a lot of repair / replacement money.
Pics:
Under the cover. Contactor is middle top, left of the capacitor (cylindrical thingie for you non-electronic types).
Closer look at the contacts on the old contactor. This is AFTER I went at them with one of my wife's emery boards while I was waiting for the new part to show up. I can't imagine what it looked like before I sanded them, or how the compressor was coming in at all.
I just replace the fan relay in mine. They last a couple of years and stick on.
I just ordered a condenser fan capacitor for my son's AC unit. It should be in tomorrow.
