The only times you think about your central air (HVAC) system are probably when you're too hot or too cold. But if you have a central air unit, a professional tune up needs to be done at east once a year, and cleaning should ideally be done once a month. Maintaining the system will save you energy and money.
Your air conditioner has three important parts: the outdoor condenser unit, the evaporator machine inside and the thermostat. All three need inspection for different reasons. Before you start a maintenance routine, it makes sense to have a replacement air filter, level and room thermometer.
The outdoor condenser pulls in air through the side and blows it out the top. If the coils are blocked, your machine will have a harder time pulling in air, run hotter and more inefficiently. Not only will this stress the motor, but also waste electricity. Listen for any abnormal noises. Is the unit struggling or any gears squeaking?
Here are the major steps for maintaining your HVAC system. Some of these will need to be done by a professional.
Cut power to the outdoor condenser unit.
Flip off the switch to the unit in the circuit breaker box. If you don’t have access to a circuit breaker box, you can also pull the disconnect.
Make sure there are no leaves, twigs or grass clippings hampering air from getting to the unit. Nearby bushes, trees and shrubs should be trimmed back from the unit.
Remove the panel and check the electronics.
Make sure the wiring looks good and there are no cobwebs. Check that the capacitor isn’t leaking or rusty.
Checking the refrigerant.
This step needs to be done by an HVAC professional, most likely during an annual tune up. They’ll have a refrigerant gauge to check the amount of refrigerant still in the unit or if you have a leak. This tool also helps demonstrate if the any of the coils are plugged. Of course adding more refrigerant should only be done by a pro.
Clean the coils.
Blocked coils can decrease the efficiency of the unit. Using a garden hose, spray water over the coils to remove the dust and dirt. Work from the center outward so you’re not pushing any dirt toward the unit. Plenty of grime will drip down underneath the unit. If you don’t think the water is rinsing the coils enough, you can also buy foam cleaners designed for air conditioners. Make sure the condenser isn’t dirty.
If so, you may want to remove the mesh to wash it down. You may want to repeat this cleaning once a month to keep the unit running efficiently.
Check the condenser's balance.
If the unit looks tilted, you may need a professional to adjust the unit’s height.
Inspect the electrical connections.
Make sure the power cords have no exposed wires. If anything is frayed, consider replacing them or securing them up with electrical tape and insulation.
Move to the indoor evaporator.
Make sure the outside of the evaporator is intact.
Check for rust stains that may point to potential leaks or condensation. Be sure no oil is dripping anywhere in between the mechanical connections. A electrician may soap down the pipes to inspect for air bubbles and possible air leaks.
Check the filter.
For the indoor unit, check the filter monthly. Depending on the type of unit you have and whether or not you have allergies, you may want to change your filter every month, every three or six months. Most filters aren’t good for more than six months. A good organizational tip is to write the date of your filter change on it so you don’t have to guess how old the filter is. If you can still see light through the paper, the filter is probably okay. If not, you’ll need to replace it. The filters are fairly affordable and available at a filter store — be sure to check the model number you need before ordering.
Be sure to check the direction the air flows through the filter when you’re removing it so you replace it the same way. If you take out the filter and don’t see which way it's pointed, you can also hold a piece of paper in the opening and check which way the air flows. If the current presses the paper downward, the airflow direction is down (up means up).
Inspect the drain pan.
The drain pan should be clean. If there’s debris or gummy residue in there, the unit should be checked if it’s a sign of any other issues.
Clear the drain line.
Be sure that the drain line from the indoor unit is is free. You may want to pour a little bleach down the line to make sure it’s clear. You may need to use a compressor or wet vac to push the water out through any clogs in the drain line. If dust settles in the line and backs up the pipe it could cause water to flow into the machine and damage the HVAC or the floor, if the leak goes unrecognized
Inspect the thermostat.
Check that the temperature in the room matches the one on the display. Using a visual read thermometer, hold it close to the unit and met sure it’s within three degrees, which is typical.