How To Repair Your Air Conditioning System

For obvious reasons, summer is the time when you are most likely to run into issues with your home’s air conditioning. These issues can stem from a number of factors including lack of upkeep maintenance and increased usage during hotter months. Since we specialize in A/C repair and all things HVAC, we want to share our expertise with anyone and everyone – which is why we put together this beginner’s guide to air conditioning repair. While we’ll still be there to help whenever you need it, with this document you’ll have the tools and know-how to act as your very own HVAC tech next time your A/C has a problem.

Tools Required

To get started, here is a short list of all the basic tools you’ll need for your air conditioner repair:

Tool	Image
Adjustable Wrench
Cordless Drill
Insulated Screwdriver
Multimeter
Needle-nose Pliers
Nut Driver
Socket/Ratchet Set
Voltage Tester

Materials Required

Here is a short list of all the basic materials you’ll need for your air conditioner repair:

Material	Image
Capacitor
Compressed Air
Condenser Fan Motor
Contactor
Fuses

Initial Areas to Inspect 

When attempting to suss out issues with your home’s air conditioning, it’s best to start broad and work your way inwards. This ensures that you don’t make the repair process any more complicated than it needs to be, as it either identifies or eliminates the possibility of more common issues with easy fixes. A lot of these types of problems manifest externally and don’t require as much handy work to correct, so it’s important to get them out of the way first before you start digging deeper and taking equipment apart unnecessarily. The main areas you should inspect first will vary depending on whether you’re having problems with a central A/C system or a window unit.

Central A/C System 

Central A/C is common in your typical single-family home, and is more likely than not the type of system your home currently uses. Central A/C usually consists of an outdoor condenser unit, an air handler that brings the air inside, a furnace that helps filter the air and duct work that distributes it to each room of the house via your air vents, all of which is controlled by a thermostat. The three components you should check first on your Central A/C system are as follows.

Thermostat Settings

The very first thing to check when your air conditioning is on the fritz is your thermostat, as you may simply need to adjust your temperature settings until you find that sweet spot. If you find yourself constantly adjusting your settings throughout different times of the day, you may want to invest in a programmable smart thermostat.

Blocked or Dirty Registers

The next component to check on your Central A/C system is your registers or air vents. These registers are where your air flow enters a room or space after making its way through your duct work. If your registers are closed, blocked or clogged with dirt, dust and other debris, the resulting air flow will be much weaker, which will in turn prevent the allotted space from cooling properly. The solution here is easy and painless – simply open, unblock, clean and/or unclog the impeded registers and air flow should return to normal.

Outdoor Compressor Surrounding Area 

Another problem that can be easily identified and fixed is a buildup of debris, shrubbery, foliage or other impediments surrounding your outdoor compressor unit. Like registers, anything that gets in the way of your compressor’s air flow can significantly detract from its overall performance. Since these units are located outside and often intentionally tucked away to prevent visibility, it’s easy for these particular issues to go unnoticed. To correct this, simply clean around your unit and clear out a decent perimeter to ensure proper air flow.

Window A/C Units 

Window A/C units are a lot less intimidating than an entire central A/C system. They are smaller in size and far more simple in terms of their design and the scope of its functions. Rather than multiple interconnected components all over your home, they consist of a single unit typically positioned into a window sill, which allows it to pull air directly from outside into your home, cooling as it passes through. While their capabilities are limited, these window units are ideal for cooling smaller spaces like single rooms or apartments without central A/C. Compact and convenient as they are, however, they are not without their problems. If one arises, there are three possible causes that should be ruled out before jumping to conclusions. 

Level of Sunlight Indoors 

Similar to a thermostat, too much direct sunlight on your window unit can throw off the cooling process. This will prevent your unit from working properly and performing to the best of its abilities, which can lead to much bigger problems over time if not corrected. This may not be easy since you only have so many windows to choose from in any given room, but try to place your unit in a spot with a lot of shade if you can. Closing curtains and blinds during the hottest times of day is a big help as well, as the unit and the room itself will be a lot cooler to begin with.. 

Window Seals

In all likelihood, your A/C unit and the window you put it in will not make for a perfect fit, which is why most require window seals. These window seals are highly prone to air leaks, especially when they are not installed properly. Left unplugged, these leaks will create a vicious cycle of counter productivity in which your unit will be forced to overwork itself, constantly blasting more cold air just to combat the hot air that it’s letting in. To prevent this, make sure the window seals around your unit are actually sealed so that no air can pass through.   

Any Vibrating Noises 

Some A/C units are louder than others, but all units make noise, and doing so usually doesn’t mean there’s anything wrong with it. If your unit is extra noisy because it’s vibrating, on the other hand, then the opposite is true. Similar to leaky window seals, the primary cause for this issue tends to be poor installation. To fix the problem or prevent it altogether the first time around, go back through the directions and double check that everything was done properly. If necessary, reinforce the unit to ensure secure installation. 

Common A/C Problems

The issues listed above are only the most obvious, surface-level complications that could be hampering the performance of your A/C system. Beneath the surface, there are many more problems that could be doing this as well. Keep in mind that multiple issues can be present simultaneously, especially in systems that have not been regularly serviced or properly maintained. Below are some more common issues to look out for.  

Dirty Or Clogged Filter  Air filters are responsible for removing airborne impurities that can aggravate allergies and cause a multitude of minor and major health issues. The more air passes through the filter over time, the dirtier they get. If they aren’t swapped out for new filters on a regular basis, this dirt will accumulate and eventually clog the filter. Once clogged, dirty filters will disrupt your system’s air flow and produce dirty air.
Incorrect Thermostat Reading  Another factor that could be interfering with your thermostat’s functionality is poor location. If it is exposed to direct sunlight or near an entrance where temperatures are constantly shifting, for example, your thermostat could be getting inaccurate readings, throwing off the gauge by which it cools the rest of your home.
Refrigerant Leaks  If you’re experiencing fluctuating temperatures from your home’s air conditioning, or you’ve lost cooling power altogether, your unit may be leaking coolant. Leaks from valves and fittings are the easiest and cheapest to fix as they usually just need tightened. Leaks from a coil are harder to fix but still manageable with a replacement coil. Larger, more prolonged leaks can lead to more serious and sometimes irreparable damage.
Clogged/Dirty Drain Line  Drain lines are similar to air filters in that they can become clogged with dirt and other built up debris if they aren’t cleared and cleaned regularly. Once the drain line is clogged, your drain pan will quickly fill up and start leaking, causing damage to the equipment around it.
Faulty Breakers It’s not uncommon for air conditioners to overheat when they are working at full blast against extremely high summer temperatures. This can kill your motor if your breakers aren’t working properly. This can in turn kill your whole system, not to mention the fact that this is a huge fire hazard.
Burned Out Capacitors While breakers keep your air conditioner’s motor from working too hard, capacitors are what allow it to work in the first place. Start capacitors provide the jolt needed for the motor to start while run capacitors provide periodic jolts to keep it running. These capacitors can become worn out over time or fail instantaneously. Gradual capacitor burn out can easily go unnoticed for a long time, preventing the motor from running as well as it should and eventually causing it to fail altogether.
Seized Compressor Compressors are what propels the refrigerant through the evaporator coils and keeps the heat exchange process running smoothly. Without the condenser, your A/C wouldn’t be able to cool the air passing through it, let alone your whole home. It’s crucial to have just the right amount of refrigerant. Too little will cause your compressor to seize, and too much can prompt failure via flooding.
Corroded Evaporator Coils Evaporator coils absorb heat from the air coming in and turn it cold before sending it on its way through the duct work. While they are located indoors and thus typically only require maintenance every three years, these coils are still susceptible to damage over time via the process of corrosion.  Too much corrosion and the damage sustained could be too much to repair.
Dirty Condenser Coils Condenser coils are located in your outdoor unit with the compressor. Since they are exposed to the elements, these coils will inevitably get dirty. If they go uncleaned for too long, the resulting buildup can have some seriously negative consequences for your system, like increased power usage for a decreased output. Unless your outdoor unit is in a particularly dirty spot, your condenser coils should do just fine as long as you remember to clean them at least once annually.
Worn Contactor  Your A/C unit’s blower motor and condenser fan motor both rely on a contactor for the electrical connection they need in order to start, as does your compressor. The contactor controls this electrical flow by blocking power whenever you turn the A/C off and connecting it when you turn it on. If your A/C won’t shut off, makes a chattering noise when running or makes a humming sound and won’t turn on, you may be dealing with a worn out contactor that’s struggling to make the necessary electrical connections.

6 Steps to Repair Your A/C System

Now that we’ve identified the most common problems that could prompt the need for air conditioning repairs, it’s time to delve into the repairs themselves. To make all the information needed more digestible, we’ve broken it down into six sequential steps that you can follow along with. Keep in mind that some of these repairs will require more time, mechanical finesse and safety precautions than others. If at any point you don’t feel comfortable attempting these repairs on your own, don’t hesitate to call a professional.

1) Inspect Easy-to-Fix Areas

To avoid getting ahead of yourself, it’s important to always start by inspecting the areas where problems are easy to find and easy to fix. Think of this as a warm-up consisting of three basic tasks you need to complete before getting into the harder stuff. First – check vents and registers. Second – see if your air filters need changed. And third – clean your condenser coils.

As mentioned above, vents and registers should be opened all the way, unblocked and clean enough that they won’t affect the air flow. Use a duster or vacuum to clean off your registers as thoroughly as possible. Most vent covers are easily removable, so you should be able to take them off to clean inside the vents as well. 

Air filters can be located in air return vents, furnaces or air handlers, so make sure you’re not missing any. Keep in mind that zoned A/C systems in larger houses usually have multiple air vents. Be sure to turn your system off before changing to avoid dust and debris blowing all over the place, including back into your vents and ducts. To swap filters, simply open the latch or access panel, remove the old filter and pop the new one in. 

Even if your condenser coils have been cleaned recently and aren’t clogged, it’s never a bad idea to clean them again. To shut down your equipment so you can do so, turn off the circuit breakers for your A/C and furnace on your home’s electrical panel, turn off the power switch located on your furnace or air handler and yank out the disconnect block on your condenser unit. Once everything is off, use a garden hose to spray your coils clean. For the best results, start spraying up to get gunk out from under the lid, then get around the coils, spray downwards to flush the dirt down the coil fins, then gently aim directly into each coil to flush out anything that remains. 

If you’re A/C still isn’t working properly after completing these three tasks, proceed with the steps below. 

2) Test the Fuses

When you remove your outdoor unit’s disconnect block to clean your condenser coils, you will likely find two cartridge fuses (standard on most units). Before you proceed with the rest of these repairs, check these fuses using a multimeter. To test them, use the lowest Ohms scale settings as you touch the red and black leads of your multimeter to opposite ends of each fuse. Numerical readings indicate the fuse still has a charge, while a minus sign or infinity symbol means the fuse is blown. Blown fuses are not self contained problems but rather signs that other components within your unit must be failing as well. You’ll still need to replace the blown fuse, at some point, but you also need to proceed with the repair process before re-starting.

3) Inspect the Access Panel

For this next step, locate your access panel by following the electrical conduit from your house. Once you’ve made sure that the power is turned off, use a screwdriver to remove said access panel. Once the panel is off, carefully check inside for any damage to wires and electrical connectors. Watch out for rodent nests when doing so, as they are often the culprits behind such issues. If you find any such evidence, do not proceed any further unless you are trained to handle electrical repairs and can safely discharge the capacitor. Otherwise, stay safe and let a professional take care of it.

4) Replace the Start/Run Capacitors

As mentioned, capacitors can wear out over time or fail in an instant. Gradual wear can do a significant amount of damage, so it’s important to check both your start and run capacitors for signs of wear even every so often. Luckily capacitors are long lasting, inexpensive and relatively easy to replace. Even without issues, it’s recommended you replace your capacitor at least once every five years just to be safe. 

To do so, first take a picture of the wire configuration for future reference before you disconnect anything. Next, it is imperative that you discharge the capacitor to prevent electrical safety hazards. Once discharged properly, use a screwdriver or ratchet to remove the bracket holding your capacitor in place. Once free of the bracket, use needle nose pliers to carefully pluck the wires from the old capacitor one by one, then reconnecting them to the corresponding tabs of the new capacitor. Once the wires have all been swapped, put the bracket back on to secure the new capacitor. To avoid a mess of wires, simply bind them together with a zip tie.

5) Replace the A/C Contactor

Like capacitors, A/C contactors help with electrical flow and keep your compressor and condenser fans charged. They are also relatively cheap and should be replaced at least every five years regardless of condition, as they are prone to wearing over time. To replace your contactor, use a screwdriver to unscrew your old contactor before removing the wires with a pair of needle nose pliers. Reattach the wires to the corresponding outlets on the new replacement capacitor and tighten where necessary, then screw the new capacitor into place on your condenser unit.

6) Test Your Repairs

The final step is to test all of your air conditioning repairs to see whether or not they did the trick. To do so, reinstall your access panel and reconnect your disconnect block to your condenser unit. Turn your circuit breakers and your furnace or air handler switches back on, and restart your system. Most A/C units (especially recent energy saving models) have a built-in delay that can cause the system to take 10 minutes or more to power back up once restarted, so be patient. Once it starts, gradually adjust your thermostat to test if the A/C responds accordingly. If after 30 minutes or more it still won’t start, or you notice that you’re still having problems once it does, it may be time to call a professional.

Repair or Replace?

If your A/C’s wear and tear and subsequently manifested malfunctions reach a point of no return, trying to keep it running with more repairs could be a futile effort. If this is the case, you may want to pursue an air conditioner replacement as opposed to air conditioner repairs. Most A/C systems have 15 to 20 years max before their best years are behind them. The older a system gets, the more problems it will inevitably have. 

This prompts a need for constant repairs, the accumulated long term costs of which can far exceed the short term costs of a new replacement air conditioner. A new system can also save you money over time, as the boosted performance and efficiency of more up-to-date models will significantly lower your monthly operating costs. Replacing your entire A/C system can be daunting, but it does pay off.

Things Looking Too Complicated? Call a Pro!

To reiterate an extremely important point: please DO NOT attempt ANY repairs if you are not 100% comfortable and confident in your abilities to do so safely. This can lead to injuries and further damage your equipment instead of fixing it. Even if you don’t carry out the repairs yourself, the knowledge we’ve shared here can help you identify problems, better understand your system and communicate with your HVAC tech more effectively next time you need one. If you’re looking for professional HVAC service from a company you can trust, look no further than our team of pros here at Meade HVAC! 

Visit maichleshvac.com/air-conditioning-repair or give us a call at (302) 328-HVAC to learn more, speak with an expert or schedule an appointment with one of our expert service techs now!