Every modern air conditioning unit depends on a capacitor or two for proper operation. In some systems, you have both a start and run capacitor. In other systems, those capacitors are combined into a dual unit. The start capacitor holds and supplies a necessary jolt of power for your air conditioner to start when necessary. It takes a lot of power to start that motor, and the capacitor ensures a ready supply. The run capacitor provides a consistent power supply so the unit can sustain operations. When one or both capacitors malfunction, you'll need an AC repair technician to fix the problem.
What are the signs of an AC capacitor failure?
When a capacitor is malfunctioning, you might find that your air conditioning system just doesn't start. If it tries and fails to start the cooling cycle, the start capacitor might be failing. If it runs and then intermittently shuts itself off, the run capacitor could be to blame. You might also notice humming or clicking from the air conditioning unit when a capacitor isn't functioning like it should.
In some cases, as the capacitor starts to fail, it provides some power but not enough. As a result, your air conditioner might run, but it may not cool the air as effectively as it did in the past. When you notice signs like this, you'll want to talk with an air conditioning repair technician about testing your capacitors.
What causes AC capacitor failure?
There are a number of reasons why an AC capacitor might fail. Age is the most common cause of failure. AC capacitors have a limited lifespan, so you might find that your capacitors fail as your air conditioning system starts to age.
If you live in an area where your electrical supply has been unpredictable and you've faced power surges, that could also contribute to AC capacitor failures. Overheating your air conditioner, whether due to excessive run time or insufficient air flow, can also tax the capacitors and cause failure.
Moisture accumulation in the air conditioner, typically due to clogged condensate drain lines, may lead to corrosion of the capacitors and damage to the connections. This causes capacitor failure as well.
When you notice signs of potential capacitor failure in your home's air conditioning system, especially if you have faced some of the most common risk factors, call a local air conditioning repair technician. The sooner you address the problem, the less chance you'll face a complete system failure.