When our air conditioners start working overtime to keep the inside cool, that strain can wreak havoc on the many moving parts inside the A/C system. Especially if it isn’t running at peak efficiency. So take the time to do some preventive maintenance. This can be the difference between enjoying cool comfort and sweating a costly service call.
Check and change air filters
While most air filters have an average life of three months, it’s important that you check them monthly during long periods of hot weather. With your A/C system working harder and longer due to the extended heat, filters fill with particles faster. Dirty air filters force your system to work harder to push cool air through your home. This uses more energy and places extra strain on the air conditioning system. Take the filter(s) out and hold it to the light. If the dust on the filter is so think that you can’t see much light shining through the filter, it’s time for new filters. A clean air filter, unobstructed by the dirt and other debris, will save you money on energy costs and prolong the life of your air conditioner. If you do not know where your air filters are or how to replace them, ask your HVAC technician to show you during an inspection.
Keep outdoor unit clean and clear
For safety, always turn the thermostat and outdoor unit’s breaker off before doing any work around that outdoor unit. Once everything’s off, go ahead and check the unit for anything blocking the unit’s sides or top. Remove any plant growth, grass clippings, or debris caught in the coil walls. Cottonwood is a big clogging culprit this time of year.
The coil can be cleaned using a soft-bristle brush to gently sweep the fins. Always brush in line with the fins, and be gentle because the fins can bend easily. Because the fan pulls air through these fins, you can expect to find dust clinging to the fins. Removing this dust and other debris will reduce resistance and increase efficiency.
Prune or remove any shrubs or other growth that is touching or close to the unit. Do not use a weed eater or other powered cutting tool that might damage the fins. Garden shears or some other type of hand clippers are recommended.
Check drain for clogs
Another important thing to check for is a clogged condensate drain. This is the drain that comes from the cooling coil drain opening on the furnace and runs to the floor drain. Clogs are usually caused by bacterial slime that grows in the water. With the A/C running, check where the line drains into the floor drain to see if water is draining. If no water is present, you most likely have a clog. Now check at and around where the drain hooks into the drain pan on the furnace. If there is water visible on the furnace and/or pooling at its base, you definitely have a clog. Turn off the A/C right away to avoid water damaging any furnace components, and have a licensed mechanical contractor inspect and unclog the drain.
Source: http://starrwriter.hubpages.com/hub/Basic-AC-Maintenance-Tips-to-Beat-Heat-This-Summer