Your air conditioner should last years with proper maintenance. It’s also important to know when to replace it. A contactor switch takes low-voltage power from your thermostat and turns it into 220-volt high-amperage power for the compressor and condenser. This part wears out and can cause your AC to break down.

The evaporator coil is an air conditioning system component that absorbs heat from your home’s air and moves it to the refrigerant. It’s one of the most important parts of your HVAC system, so it’s no surprise that it gets dirty.

Even a thin layer of dirt can reduce the efficiency of your system by blocking heat transfer and making it less effective. It also forces your system to work harder, using more energy.

As the evaporator coil absorbs heat, it also condenses moisture from the air. This water drips down the inside of the air conditioner unit and into a drain pan, where it’s then drained out of the system. Dirt buildup can also lead to a clogged condensation drain. A clogged drain can cause many problems, including water damage, high humidity, and unpleasant odors.

You can’t easily fix A dirty evaporator coil on your own. Accessing this part of the unit is difficult because it’s located up in the internal unit or near the blower fan in the attic. Plus, it’s often electrically charged, so attempting to reach it without proper training can lead to electrocution.

The thermostat is a delicate piece of electronic equipment that gathers dust and other debris over time. This buildup interferes with the thermostat’s ability to read room temperature accurately, so it should be cleaned regularly. To do this, remove the cover and clean any dirt or gunk from the inside. You can also use compressed air to blow away debris. If the thermostat has contact points and a bimetal coil, use a clean paintbrush or Q-tip dipped in alcohol to clean them.

If the readings from the sensor and the settings don’t match, it may be a sign of a dirty thermostat or a problem with the wiring. Thermostat wiring can become disconnected or corroded due to age or improper installation, so a professional should be called in to fix this issue.

A jarring bump or bad installation job can knock a non-digital thermostat off of level, which can affect its calibration and cause setting and temperature discrepancies. If this is the case, use a carpenter’s level to correct it.

When your AC is working, the fan is supposed to help push hot air from the inside of your home across the condenser coil to be cooled. When this isn’t happening, the fan can overheat.

To solve this problem, first make sure the circuit breaker is not tripped. If it is, reset it. If not, the problem is probably the condenser fan or its motor.

A dirty fan contactor can also prevent the fan from turning on. When the contactor switch is turned on, it clamps down between two sets of metal plates. This creates a short arc of electricity. Over time, this repeated arcing eats away at the metal contacts and leaves them covered in a black layer of soot.

If your fan is humming when power is on but the blades move easily when you wobble them with a stick (with the power off) this can indicate a bad motor bearing. This is a DIY project that can be done with the right tools and training. See this video from Word of Advice TV to learn how.

Located outside your home, your AC unit’s condenser coil is responsible for rejecting the absorbed heat to the atmosphere. The air that cools your home is first blown across the evaporator coil where it is cooled before it’s circulated through tubing and the condenser coil. When the condenser coil gets dirty, it’s unable to reject this heat and your air conditioner won’t be able to perform properly.

Dirty coils also cause a variety of other problems including increased energy consumption and decreased cooling efficiency. They also shorten your AC unit’s lifespan.

Both the evaporator and condenser coil should be inspected and cleaned regularly. The best way to do this is by having a professional HVAC technician perform regular maintenance on your system. You can also do a few things on your own to keep the coils clean, such as minimizing dirt buildup by keeping the area around your outdoor unit clear and trimming vegetation back 2 feet (0.6 meters) to allow for adequate airflow. You can also purchase a tool from your local air conditioning wholesaler that will comb the aluminum fins on your evaporator and condenser to help them stay straight and free of obstructions.

The compressor is called the heart of your air conditioner for a good reason. It’s one of the most reliable parts in your AC system and, with some basic maintenance, it will likely work flawlessly throughout its lifetime expectancy. However, the compressor can also be one of the most expensive components to repair or replace. Here are the top reasons your compressor can fail, and how you can prevent it from happening:

Since the outdoor component of your air conditioning is exposed to dirt, dust, leaves, debris, bird droppings, and other contaminants, the coil can get dirty quickly. When the coil is clogged with grime, your air conditioner will have trouble expelling heat from your home and your compressor will overheat.

When the compressor overheats, it can create acids that damage contactors, wiring, and fuses, which will then impact the entire system. Your HVAC technician will be able to identify these acid buildups and perform the necessary repairs before they become serious problems that require replacing parts or your entire air conditioner.

As your air conditioner thaws, the dirty water that formed on your evaporator coil will drip into a condensate drain pan and then flow outside through a white PVC pipe. Sometimes dirt picked up on the way forms a clog in this drain line. This can cause the evaporator coil to freeze again, and you’ll have to call for an AC repair service to deal with this issue.

Your AC needs unrestricted airflow to function properly, and when something obstructs this airflow your air conditioner can be forced to work harder than it should, leading to higher energy bills and more frequent AC repairs. A clogged or dirty filter can restrict airflow, and if this is the case you’ll need to replace it before you try to solve this problem on your own. You might also have a physical issue with the AC like bent or broken coil fins, loose or damaged connections, or other damage that only an experienced professional can resolve.

If your air conditioner seems to be switching on and off randomly, or isn’t cooling at all, the problem could be a dirty ambient temperature sensor. A faulty sensor can’t relay accurate readings to your air conditioner, and it can even cause the entire system to shut down, so you should call an HVAC technician right away.

To test your thermostat’s ambient temperature sensor, first shut off the power to it by flipping the switch at your breaker box. Then, remove the cover on your indoor unit and look at the sensor. It should be close to the evaporator coils, but shouldn’t make direct contact or be bent away from them.

If the sensor is dirty, use a cotton swab or soft cloth to clean it gently. Don’t touch it with your bare hands, as the oils from your skin can affect how accurately it reads. Once it’s cleaned, replace the cover and turn the power back on. Keeping your air conditioning’s sensors clean is an easy way to prevent inaccurate readings and save energy.

The condenser coil is located in your air conditioning unit’s outdoor unit and it is responsible for transferring the heat that the system absorbs from your home’s indoor air to the outdoors. Your air conditioner needs to have the coils cleaned regularly to keep them cool and functioning properly.

Dirty coils are a major problem for AC systems because they force the system to work harder. This extra stress can lead to premature wear and tear, a decrease in cooling efficiency and expensive electricity bills.

Dirty coils are also problematic because they insulate the air conditioner and prevent it from releasing the heat that it extracts from your home’s indoor air. If you have a dirty evaporator coil or condenser coil in your air conditioning system, you will most likely notice that your electricity bills are much higher than normal. This is a good indication that the coils need to be cleaned. The evaporator coil can be cleaned by the homeowner, but the condenser coil must be cleaned by a professional service technician.