Fully functional air conditioners are hugely important in creating comfortable living and working spaces as the seasons change. A misfiring AC unit can make for an unbearable environment, so regular inspections and maintenance are necessary. Depending on the type of unit you have, repairs and replacements can be costly. Checking on essential components, cleaning the unit, and replacing worn parts can extend the lifespan of an appliance and keep it running efficiently for longer. 

Although traditional air conditioning systems operate using ductwork, many modern homeowners opt for a ductless mini split air conditioner due to its efficiency, reduced carbon footprint, compact design, and long-term cost savings. These systems can provide custom temperature controls to individual zones within a building, meaning each indoor air handling unit should be carefully maintained for optimum performance. 

For any heating and cooling system, it’s best to get an annual AC inspection and service from a professional technician. Most systems have warranties that are dependent on regular servicing. While trained technicians are the most reliable option for maintaining your appliance, there are several things you can do to keep your air conditioner in peak condition year-round. Let’s take a look at some key tips for completing an AC inspection.

Check the Thermostat

The first step in an inspection is to check the thermostat. Many air conditioner problems are thermostat-related. Problems with your thermostat may manifest by causing issues resembling a more significant complication. Fortunately, most thermostat faults are quick fixes and shouldn’t be too costly. 

If the thermostat delay isn’t as brightly lit as it should be, there is likely a lack of power supply to the appliance. This may be because of dead batteries, a tripped breaker, or a worn fuse in the electrical service panel. Open the thermostat and look for signs of wear, such as a build-up of dirt or dust. If there is debris present, clean the components carefully using a Q-tip. 

Once the interior is clean, ensure all components are tightened before switching out the batteries for a fresh set. If there is no change in performance, the problem lies elsewhere. 

Poor thermostat positioning is also a common issue. If the thermostat never reaches the temperature set on the appliance, it may be because it’s positioned incorrectly, making it impossible to regulate the temperature accurately. Ensure it isn’t exposed to direct sunlight, heat, or cold sources.

Another common thermostat issue is short cycling caused by a poorly calibrated anticipator. This can be fixed by adjusting the anticipator arm in one-notch increments toward the “longer” marking on the dial. Allow the unit to complete an entire cycle between adjustments to gauge any improvement. 

If you experience persistent problems with your thermostat, it might need replacing. Call a professional technician to get an accurate diagnosis of the problem. 

Test the Heating and Cooling Modes

If your air conditioner has heating and cooling modes, you should check they are functioning correctly. Set the thermostat to various temperatures, both hot and cold, and ensure the unit disperses air at these temperatures. Inaccuracies may be down to several factors, such as clogged filters, an obstructed outdoor unit, a lack of refrigerant charge, or worn components. 

An uncommon but potential problem is a malfunctioning defrost cycle. Defrost modes are rarely used in certain locations, as the outdoor temperature doesn’t regularly drop below freezing. However, it is a vital setting in some areas, as frost build-up on a condenser unit can drastically affect temperature regulation. 

When a mini split heat pump is set to defrost mode, it causes the outdoor coil to heat up and the indoor coil to cool down. This helps get rid of any build-up of ice or frost when temperatures are low. In such circumstances, the defrost cycle is integral to the efficient operation of your appliance. 

If you are testing your appliance during winter, check your outdoor unit for ice or frost. If your system is experiencing difficulty with the defrost cycle, switch it off immediately. Allowing it to run with a malfunctioning defrost cycle could cause significant damage. Hire a technician to explore the causes and find a solution. 

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Turn Off the Power

When inspecting other parts of your AC unit, you must turn off the power because you will be making contact with electrical components and removing parts of the interior; you can harm yourself or the unit by leaving the power on. 

Switching off the unit doesn’t just mean turning the thermostat to zero. The unit may still be active at this setting, increasing the likelihood of electrocution and appliance damage. To turn off the air conditioner completely, you must find the switch for the condenser unit on the external circuit and set it from “On” to “Off.”

At this point, the unit is safe to adjust, service, and clean. 

Remove Obstructions from the Outdoor Unit

Your outdoor unit should be clear of any shrubbery, debris, sand, dirt, or other obstructions. As a guide, try to keep trees, plants, and different vegetation types at least two feet away from your external unit. Throughout winter, it’s useful to place light wood or plastic over the unit to prevent debris, snow, and other loose items from gathering around it. But be careful not to entirely cover the unit because it makes an ideal nesting spot for vermin.  

In general, a shaded area outside of your home is the best location to place your outdoor condenser. Try to shield it from the elements, including direct sunlight, rain, or snow.

No matter how perfectly you position your condenser unit, debris tends to gather around it over time. Periodically check on your unit and clear away any leaves or obstructions that might have accumulated.

Ensure the Unit Is Level

To avoid excess debris from blocking the outdoor unit, many people elect to mount it using brackets. There should be at least five inches of space between the wall of your home and the unit and a minimum of twenty inches of space above the unit. You’ll need to check that the AC unit retains its position periodically because it may shift over time while in operation. Whether the wall mounting brackets begin to decay or the weather causes the unit to move, an unlevel condenser can cause a system failure. 

Take a spirit level outside and ensure your condenser unit is balanced. Slight adjustments to the unit shouldn’t be problematic. However, if you’re repositioning it entirely, you must hire a professional. Otherwise, you may accidentally bend the refrigerant lines, causing a leak, which can be expensive to repair. 

Inspect the Fins

There are two main types of fins in an air conditioner: condenser fins and evaporator fins.

Condenser fins are located on the outline of the exterior air conditioning unit. They are slender metal slats that help to deflect warm air from the unit as it runs. They must be kept in reasonable condition for your AC to continue operating efficiently, mainly when the outside temperature is very high and your AC system is in constant use. 

Evaporator fins are found on the inside of the air conditioner around the evaporator. Their job is to cool the outside air when it enters the unit before pushing it through ducts or piping into your home. These fins often become dirty and blocked, diminishing their performance and making the air much warmer as it enters the room. This causes your conditioner to work harder while insufficiently cooling your home. 

Fins are quite durable, so they can be sprayed using a garden hose. If the fins are very dirty, you can purchase a specialized fin-cleaning spray from a hardware store to remove built-on grime.  

When the fins are clean, ensure you place them back into their correct positions. Fins should be straight to maintain efficient airflow year-round. You can use a butter knife or straightening tool to position them accurately. 

Check the Condition of the Evaporator and Condenser Coils

Evaporator coils are essential in capturing heat from the air within your home, and condenser coils transfer this air into the outside unit. Both coils are crucial in the transfer of hot and cold air, which is the most important function of an air conditioner. 

Due to the amount of work they carry out, coils tend to get dirty. As they continually transfer air to and from a building, they accumulate dust, pollen, and other airborne particles. Dirty coils significantly diminish the performance of your AC, causing issues such as poor heat transfer, reduced cooling capacity, increased energy consumption, and more wear on the overall system, which can lead to further damage.

Check the evaporators on the internal unit monthly. If there is a build-up of dirt or grime, clean them using compressed air, a soft brush, or a shop-bought commercial coil cleaner. Ensure you drain excess material using the drain pan.

Consult the owner’s manual for exact instructions on how to access evaporator coils. In general, the process involves removing screws and fasteners from the access panel cover and accessing the coils. 

To clean the condenser coils, switch off the AC. Remove the outer caging and adjust the fins for access. A coil cleaner is perhaps the most convenient substance to apply to the coils. Ensure you dry all components before putting the unit back together. 

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Clear the Evaporator Drain Line

During an AC inspection, you must check the evaporator drain line for clogging. A clog in the drain line can cause a significant leak in your home or may stop the system from working entirely. Signs of a clogged drain line are drain pan leaks and your system struggling to start. In either of these scenarios, make sure to check the evaporator line immediately. 

The drain line and drain pan are located at the bottom part of the indoor air handler. Any moisture runoff from the heating and cooling process gathers in the pan before flowing through the drain line into the drain. When moisture combines with dust or debris, it creates sludge that can block the drain line.

An effective way to clear the drain line is to use a wet dry vacuum. This sucks out any loose debris, allowing the water to pass through freely.

Monitor the Condition of the Air Filters

Whether you have a multi- or single-zone mini split system, each indoor air handling unit has its own air filter. The condition of these filters must be monitored regularly to ensure air quality is optimized and your conditioner operates well. An air filter traps allergens, pollutants, dust, and debris, keeping the air clean, but, in doing so, it accumulates these particles. 

To inspect filters correctly, remove them from the air handler. Make sure the power is switched off entirely before opening the front panel. Wipe the interior with a soft dry cloth and remove the filter. Most filters can be washed two to three times, but you should check the packaging guidelines to be sure. Once they are worn, you should replace them with fresh filters. 

Dry off the filters in a shaded area and place them back in the correct position. There are usually small tabs at the bottom of the filter area that allow you to click them into place. 

Check the Refrigerant Charge

Mini split systems are connected to refrigerant lines and use a liquid called Freon in the cooling process. Freon is also known to leak on occasion, causing significant damage to the AC system. If Freon is running low, it must be recharged. 

There are several ways to check the refrigerant levels without the help of a professional. First, if you notice a build-up of frost on the motor, tubes, or other system components, there might be a Freon leak. Second, if your system is making a hissing sound, it could indicate a leak; the liquid makes this noise as it escapes. Finally, if you suspect a leak but see no evidence, an electronic detector tool scans the unit and signals when a leak is detected. 

If you have a multi-zone system, such as a 4-zone mini split, make sure to check each individual air handler. 

What to Do if Issues Are Detected

If issues are detected, you should call a professional technician to determine the full extent of the problems and handle repairs and replacements. In some cases, the repair work is very costly, meaning a new system may be a better option. 

For a total system replacement or spare parts, get in touch with ComfortUp. We are a leading supplier of ductless air conditioning systems and we stock quality products, parts, and accessories for most sought-after brands. Our systems are backed by a manufacturer warranty, provided you have the unit installed by a licensed HVAC contractor. Give us a call today or visit our online store to see our full range of products. 

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