Your home's air conditioner should probably run for many years before it suffers a major breakdown, but when you do notice any problem, you might take a few minutes to try to troubleshoot this yourself before calling a contractor. Some problems with air conditioners are very simple and can be addressed by a homeowner, and some may not even be the fault of the air conditioner itself. Note a few of those here so you can know what to do when your home's air conditioner acts up.

1. The air seems lukewarm and dry or dusty

If your air conditioner is blowing air through the home's vents but it feels lukewarm rather than cold and you can tell that it's dry or dusty, it may be that your home's ductwork needs cleaning. After many years, a home's ducts can easily collect dust and dirt, and the air conditioner will blow these things through the vents as it works. This dust can also make the air feel warmer as it circulates. You can often remove a vent in a room and use a flashlight to check the ducts to note if they seem very dusty and dirty; having them cleaned by a professional is often all you need to have cool, clean air again.

You might also check the grills to the outdoor unit for ice that may have formed. This can signal a leak in the refrigerant; without enough refrigerant, the air won't get cool. The ice can also be blocking the air circulation around the unit, not allowing the remaining refrigerant to cool the air. You can clean the ice but have a technician check for the cause of the leak.

2. The unit is suddenly very noisy

If you hear a thumping or rattling noise from the central air unit, shut it off and switch off the circuit. Open the hood that holds the fan blades and check inside for any rock or debris that may have gotten past the grill; even a small lizard could have crawled in and is being knocked around! Note if the fan blades are bent and give them a whirl by hand; if they scrape the cover or don't spin evenly, they will thump around and now need to be replaced.

There is also a small electrical part inside called a capacitor that is typically held to the unit with a bracket; if the bracket has come loose, it will rattle or make a thumping noise as the unit works. You can often just tighten the bracket with a screwdriver or replace it easily enough.

Make sure to get air conditioning repair done promptly lest you be stuck sweating all summer long.