The Complete AC Maintenance Guide: How to Keep Your AC in Peak Operating Condition

When summer hits it’s not all barbecues and sweet tea. The humidity and high temperatures can make life indoors a living hell, especially if your AC is not working properly. And at night, there’s nothing worse than trying to sleep when it’s too hot. 

Keeping the air conditioning unit well-maintained is the key to keeping comfortable through the summer. A properly maintained AC unit will not only save energy and money, it also extends the lifetime of the unit, prevents major repairs and saves you money in the future. 

There are many things that you can do yourself to maintain your unit to keep your AC running smoothly. Here are some tips for air conditioner maintenance. 

Important note: Before you do any work on your AC, make sure to shut off the power so you can work safely. For the exterior condenser, check for an exterior shut-off box close to the unit – it typically has either a metal or a plastic cover, fixed on the house’s wall. Inside, turn off the power at the breaker box.

Outdoor Condenser Maintenance 

How does it work?

To understand the maintenance that your condenser needs, it’s helpful to know how it works. 

The condenser is a box that is surrounded by coils. These coils have heat collected from the air inside. The outer part of the condenser has openings where outdoor air can go through and collect the heat from the coils. This hot air is expelled by a built-in fan. Once the coils have their heat removed, refrigerant is pumped back inside.

In a nutshell, the condenser expels the heat of the air inside your home to outside. And to well maintain it, here’s what you can do: 

  1. Remove debris

Remove the fan cage. Unscrew the fasteners and lift the fan grill away from the condenser and remove leaves and other debris. 

If you haven’t used your AC for a while, the fan might be stuck.  To loosen it, manually push it (gently) to complete a couple of turns. 

  1. Clean the coils

As the condenser gets air from outside, it collects debris and dust that gets stuck to the coils and clogs up the openings for air intake. You can use a hose to wash the coils both inside and out. Aim the water in different positions to get all the areas clean. The side facing the house will always be the dirtiest; you might want to give extra attention to that. 

Do not use a pressure washer because it can bend the condenser’s fins. It’s not recommended that you use to use chemicals cleaners as many of them are corrosive (especially if the coils are made of aluminium) and they can cause damage. Plain water will do the trick just fine.

You should clean the coils at the beginning of summer and check throughout the season to see if another cleaning is needed. 

  1. Straighten Coil Fins

If the coil fins are bent, that can restrict airflow and reduce the efficiency of your condenser. You can use something thin, like a butter knife or a fin-straightening tool, to carefully unbend the fins. Don’t get more than half an inch in. 

  1. Check wires (if you feel comfortable doing that) 

Again, make sure the power running to the condenser is OFF. Locate the power box that should be next to it, open it, and turn the power OFF.  It’s also good to turn off the circuit breaker for your AC. 

If you have a voltage pen or a  voltage meter, you can double-check to be sure that there’s no voltage running to the unit.

Once that is done, you can open the electrical part of the condenser. To locate it, follow the whip that comes out of the power box. You can unscrew and remove the door and the panel that protects the wires. 

That’s where mice and other small critters like to make nests during winter. Check carefully for any bare or loose wires. Also, see if the connectors in the capacitor are in good condition by wiggling the wire a bit.  Some connectors just fall apart. Don’t touch the capacitor as it may be holding a charge.

If you find broken, corroded connectors, you can cut that piece off, strip the end of the wire and change the connector if you feel comfortable doing that.  You can use electrical tape to protect bare wires.

  1. Suction line insulation

You will find two pipes coming out of the condenser, a thin one and a thicker one. The thicker is a suction line and should be covered with insulation foam to protect the refrigerant.

It’s common to have missing parts of foam around the pipe as some animals like to chew on it. If the foam is gone, you can replace and attach it with a zip tie. 

  1. Level your condenser

If your condenser is leaning too much to one side, you should level it up. If it’s too inclined, the condenser is more likely to fail sooner than it should.

When levelling it, it’s important not to move it too much because there are copper pipes in your unit that will probably cause a refrigerant leak if they get broken.

Indoor Evaporator Coil Maintenance

The evaporator coil is where refrigerant removes heat and humidity from the air.  The often called the A coil because of its A shape. It usually sits over the furnace.  If you have trouble finding it, look for the suction line with the foam insulation and see where it goes. 

When the humidity is collected, that water drains down the coil. At the bottom of it, there’s a duct where the water is expelled. 

Above the coil, you will find two ducts: the supply duct that gets air from inside your home, and the return duct that returns cool air back to the house. 

  1. Check temperature differences

The first thing you can do to check if your AC unit is working properly is to check the difference in temperature of the return and supply ducts. 

Turn the unit on and wait five to ten minutes. Then use a poke-in thermometer to check the temperatures. Place it above the ducts. The difference should be around fifteen to twenty degrees. 

You can take these measurements on the main floor by putting the thermometer inside the vent where the cool air comes out and check the room temperature. 

  1. Clean condensate drain line

If there’s water around the furnace when the AC is on, your drain line is most likely congested. One way to prevent that is to keep the drain line clean and unobstructed. You can either air blow or pour a mixture of water and bleach down the line. 

You should also clean the fitting that connects the tube to the coil, which can get clogged over time.

  1. Get a new furnace filter 

Regularly replacing your furnace filter can help to keep good airflow, which is essential for the optimum functioning of your AC unit. 

When the AC is on, it pulls air with a speed higher than the furnace, meaning it can collect a lot of dust so replacing it every month or two is a good idea. With filters that promise to last one year, they still should be replaced after six to eight months. 

Beware filters that promise to “purify” the air as they can reduce airflow. When airflow is compromised, the indoor coil might get frozen. 

When installing a new blower filter, make sure to follow the arrow instructions on the package to match the airflow arrows to the AC unit. 

The new and clean filter will help to make your AC perform more efficiently.

  1. Clean Furnace Blower Wheel

Before inspecting the furnace, be sure to turn the power to the furnace OFF.  

Remove the doors of the furnace and locate the blower wheel at the bottom of the unit. Over time, the wheel fins can get very dusty.  Carefully, lightly touch the fins. Go easy on this step because the fins are often sharp. If you feel the dust, you should consider cleaning it, as that dust prevents airflow. 

To clean it, unscrew the control panel and move it away from the blower wheel. Try to avoid disconnecting any wires. Once you unscrew the blower, bring it out of the furnace box, brush and vacuum it. 

The Main Floors Tips

  1. Keep supply and return vents clean and open

Closed or blocked vents will restrict airflow, and you need unrestricted air flow to keep your unit running well. Closing vents off may cause your furnace to overheat. You shouldn’t close more than one-third of your supply vents.

You can vacuum the vents, unscrew the plastic cover and clean inside to remove dust from the return vents. 

  1. Change your thermostat batteries

Detach the thermostat can from the wall. If the thermostat face goes blank, it runs on batteries that can be easily replaced. 

The best way to extend the life of your air conditioning unit to have regular inspection and maintenance performed by a qualified technician. Call Forney Air at (214) 924-9745 for a fast and efficient service.

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