How To

Can I Fix my Central Air Conditioner?

The summers in Kansas can be brutal. In the July and August months we can see one-hundred plus degree temperatures for weeks at a time. If you couple that with the high humidity it can be an outright miserable experience. Most folks get away from this heat by retreating to the confines of their home where their central air conditioner keeps them nice and cool.

What do you do though when you come home only to find that your central air conditioner isn’t working anymore? Perhaps you come home and notice the home is much hotter than it should be. You go and check the vents and feel air being pushed through… but its lukewarm air. Or, perhaps you go and check the outside unit and see that it’s covered in frost and ice. Whatever you encounter the end result is the same: Your home is not being cooled.

So, how do you fix this? How can you get your air conditioner working again? Well, in most cases folks you will have to call a service company to come out and troubleshoot your air conditioner to determine what the problem is. That being said, before you make that call there are a few things that you can check yourself to ensure that you aren’t looking at a simple fix. After all, it’s much better to fix it yourself then have to pay for a service call.

Do-It-Yourself Checks

Before you end up calling a local service company to take a look at your system there are a few things that you can do to troubleshoot your system. First things first though, if your system is covered in ice or frost then turn off your air conditioner and wait for the ice/frost to melt. Once the ice has dissipated we can began troubleshooting. (If there is no ice then turn your system off and start troubleshooting right away.)

Ok, now that we’ve got our system turned off there are a variety of things that you can check and do before we call that tech out. The very first thing I check every time when something goes wrong with my system is the filter. Ideally, your filter should be changed every few months to ensure that clean air is circulating through your home and that dust does not get trapped within your air conditioner/furnace.

If you have not changed your air filter for quite a while then this could be the problem that you are having. Not changing this filter regularly will result in poor airflow due to all of the dirt and grime that gets stuck to the filter. This poor air flow will restrict the amount of hot air that your evaporator coils receive. Without the needed hot air your evaporator can freeze.

By either cleaning or replacing your filter with a new one you may be able to prevent this from happening again and only be out twenty or thirty dollars. If you are unsure on what kind of air filter to purchase check out our ‘Best Air Conditioner Filter’ guide by clicking here. Also, when you are changing your air filter take your vacuum with you with a hose attachment. Then, when you take the old filter out insert that hose attachment in there and suck up any remaining dust that remains. This will ensure you get a nice clean air before you insert the new filter. (Some people use brooms for this as well to sweep out any remaining dust.)

The next logical place that I am going to check is the thermostat. This may sound like a stupid question, but is it set to cool? If it’s not, don’t feel ashamed. I’ve had it happen to me as well. My toddler thought it’d be a fun idea to play with the thermostat before we left for the day. When I came home I was greeted with a surprise. If the thermostat is set to cool then what is the fan setting at? Not all thermostats have this setting but if you do have a fan setting make sure that it is set to ‘Auto’ and not set to ‘On.’ If you do have it set to ‘On’ then you will have the blower motor blowing air constantly… even if the air conditioner isn’t on. So, you’ll get warm air blowing through your home. Lastly, it could be that the thermostat itself is bad and isn’t reading temperatures correctly. If this is the case then this would fall more in line with a service call.

Another area to check is your drainage line. The drainage line comes off your inside unit and should be a smaller plastic tube. The end of the tube should be routed to a drain in your floor. This drainage tube attaches to your condenser. Remember, that your condenser removes heat AND humidity from your home. When removing humidity condensation can occur and water can form. This is what your drainage line is for. Occasionally, your drainage line can get clogged with dirt and debris. If enough is in there it will prevent water from flowing outwards. The water will get stuck and will either find a way out to spill on your floor or it will back up towards the condenser and freeze. The freezing water will crawl back up the tube and may even freeze your condenser. All you need to do to correct this is wait for the ice to thaw and then clean out your tube so that water can flow freely to the drain.

There is one more check we can do before we move outside. A lot of homeowners like to close vents in rooms they are not using. This is seen as a way to save money. This is all true, but if you close too many vents in your home then that cold air has nowhere to go and could end up freezing some of your lines or your air conditioner itself. Try opening up all of your vents when you turn on your air conditioner again. Watch to see if the problem occurs again. If it doesn’t, then try closing one or two vents, then watch your system again. Rinse and repeat until you determine what the ‘perfect’ number of closed vents is for your home.

The last check that you can do before you need to call a service technician is inspecting your condenser on your outside unit. The condenser is located on the side of your outside air conditioner. When looking at it you will notice hundreds of fins all around it. How dirty do they look? Are there leaves, dirt, and other debris wedged in there? If so, get a garden hose with a controllable nozzle. Set the nozzle to a low setting and gently spray the side of your AC unit (The condenser) with the water. Be sure not to use high pressure water as you could risk damaging the fins of the condenser. This can be an expensive repair, so be careful. Also take care not to spray water directly on top of your air conditioner.

Service Call Worthy

Ok folks, so we now have gone through every possible thing we can do before calling an HVAC company. There are some things though that we just aren’t able to fix. If none of the solutions we offered above have helped then you are most likely looking at one of these scenarios that will require a trained professional.

Low Refrigerant

The first and most common issue in HVAC troubleshooting is that you are low on refrigerant. If your system isn’t cooling your home or is blowing warm air then it is likely that it is low on refrigerant. Refrigerant is the ‘blood’ of your air conditioner. Without refrigerant your system cannot absorb the heat from your home. If you do have low refrigerant do NOT just add more refrigerant to your system. Refrigerant flows through your air conditioner in an endless cycle. In other words, you should never run out of refrigerant… unless you have a leak. If you, or your service tech, adds refrigerant to your system without fixing the leak then you are just throwing money out the door. You are going to have the same problem again when that new refrigerant leaks out.

Instead, your service tech needs to identify where the leak is coming from. Is it on the refrigerant lines going back and forth between the evaporator and the condenser? Is it in the outside unit? Or, in the inside? Once the leak has been determined the technician will patch it and then recharge your system. While the patch may not be too expensive the recharge of refrigerant can get quite pricey, especially if most of your refrigerant has already leaked out.

Also note that you may have more than one leak in your system. This can happen in the piping of older systems. Sometimes the old piping can get corroded and cause multiple micro fractures throughout the lines. In this case your service tech may need to replace the entire pipe.

Faulty Compressor

The other most common problem with a central air conditioner is a bad compressor. If refrigerant is the ‘blood’ of your air conditioner then the compressor is the ‘heart.’ The compressor is what circulates the refrigerant throughout your system. If there is a problem with the compressor then it will most likely need to be replaced.

Unfortunately, a compressor replacement can be an expensive repair. It could be a couple hundred or it could be six or seven-hundred. It is hard to gauge this as there are other factors to consider. Such as what size is your air conditioner? Did the broken compressor cause other problems? Does the system need a recharge of refrigerant?

Yes, that’s right. In some cases you could have a faulty compressor and need a refrigerant recharge. If that is the case then I’m sorry to say that you’re going to have a hefty repair bill.

Duct Work

Depending on how comfortable you are, this could be something you could do yourself. I would still recommend contacting a professional though. You could be lacking air flow due to faulty ducts. This problem doesn’t usually just ‘happen’ randomly though. This is something you would encounter when moving into a new home. For example, my old house had a big old gash in the duct work in the basement. When I walked by I could feel the cold air coming through the hole. I did my redneck fix and duct taped the hell out of it. It fixed the problem.

Depending on your house your duct work is going to run through your basement and your ceiling. Inspect all of these ducts and look for any visible signs of damage or even open areas. Please take extra caution when working in your attic as a wrong step can not only send you through the ceiling but can also lead to injury. The same caution should be exercised if you are working in a crawl space. (Many folks like to put poison in their crawl spaces to deter animals and pests… sometimes this can affect humans as well.)

If the duct work only needs a few patches here and there then you could take the duct tape approach. But, if you are finding some glaring issues then it would be best to call an HVAC tech for repairs.

Faulty Blower Motor or Fan Motor

These are two different distinct parts but they accomplish similar goals. The blower motor is located inside your home and has the goal of blowing the air across the cold evaporator coils. The then chilled air flows throughout your home. If you have a low quality blower motor then you will struggle to have that cold air pushed through your room. This can be solved by replacing your old blower motor with a new model. Also, in some cases the blower motor that comes with your home can be improperly sized. The motor itself could be working perfectly but it’s just not large enough to push the air through your home. A larger blower motor would solve this issue.

The fan motor is located on the outside part of your air conditioner. This is the motor that gives the power to the fan that is located at the top of your outside air conditioner. The goal here is to expel the heat. If the fan, or motor, is not working correctly then you will have trouble removing the heat from your home.

Other Misc Parts Within Air Conditioner

While we have covered all of the most common air conditioner failures there are always one off occurrences that can happen. As an example, in my old house our air conditioner stopped working entirely. We called a tech out to service the machine and found that a capacitor had blown. So, while it wasn’t the blower motor or the fan motor that went out… it was the capacitor that kept those motors running that broke.

Air conditioners are complex machines and you will always have a risk of those smaller ancillary parts and components giving out as well. If you’re not sure it is always best to call a technician out to service the equipment.

Conclusion

Well folks, after reading this you should have a pretty good idea of what you can and can’t do when it comes to servicing your air conditioner. While some of you may want to go above the do-it-yourself section we should inform you that the handling of refrigerant is strictly regulated.

You are not legally allowed to handle HFC or HCFC refrigerants unless you are Section 608 Clean Air Act certified with the Environmental Protection Agency. If you do not have this certification then you cannot legally handle or charge air conditioning equipment.

Thanks for reading and I hope that I was able to answer your questions,

Alec Johnson

RefrigerantHQ

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