There are a handful of simple air conditioner maintenance tasks that don’t necessarily require professional expertise, like replacing an air filter, clearing away obstructions from vents, or fixing a small rattling noise cause by a loose screw.

 If you are determined to do-it-yourself, even moderately difficult unit maintenance tasks—cleaning out ducts, tuning up your system, checking condensate draining, etc.—can be figured out through a quick Google search.

 But occasionally there comes a time when your heating and cooling unit is in need of more knowledgeable hands. If you notice any of the following signs coming from your AC system, then it’s time to call a heating and cooling specialist.

 Takes a Long Time to Cool

Summer in North Georgia and around metro Atlanta can be brutally hot, so it’s difficult not to notice when it takes a long time to cool your home. Although this may just seem like a minor inconvenience, a sluggish cooling unit can be one of the first indicators that your system is close to failure. The solution may be as simple as refilling low coolant levels, or as complicated as rusty piping, which would require a whole new system. Regardless, it is highly recommended that you contact a repairman immediately just to be safe.

 Blows Warm Air

If your AC unit is blowing warm air into your home, there are a few preliminary tests you can do before calling a repairman. First, check your thermostat to make sure it is on cooling mode. (This may seem like a simple solution, but it happens more often than you’d think.) Also, check your air filter to see if it is clogged and needs to be replaced. A dirty filter will block the air flow from reaching the coil, which causes poor unit performance. A filter needs to be replaced every 30-60 days.

 If your unit passes these tests, then it may have a malfunctioning compressor, in which case you will need to call an expert.

 Excessive Cycling

Units that seem to cycle on and off more than they should generally suffer from one of two things, or a combination of both: the thermostat is malfunctioning, or cold air is escaping outdoors somehow. Excessive cycling causes unnecessary wear on your unit, and if gone unfixed, could lead to bigger problems down the road.

 Unusual Smells

An air conditioning unit should never give off strange odors. If yours does, it may be a sign of mold or a damaged duct work. Check to make sure the exit hose or condenser isn’t clogged first. If the smell persists, contact a repairman.

 A little DIY maintenance is always a good thing, but the trick is to know when to throw in the towel and call a professional. If you notice your AC unit displaying one of these warning signs, then it’s time to give an Atlanta heating and air conditioning contractor a call.