6 Common Air Conditioner Problems and How to Fix Them

The seasons have changed, signalling the arrival of cooler temperatures and a period of unpredictable weather.  


In regions that experience defined seasons, there can be months during which the air conditioner is not in use and so it is recommended that you check that it is functioning properly and as expected. 


Whilst you can’t control if there is sun, rain, or snow, there is one thing that you can do to maintain your indoor comfort during the upcoming season. Check for common air conditioner problems.  


In this article, we look at 6 of the most common air conditioner problems, how to check for them and what action needs to be taken to fix them. In some cases, these can be solved without the need for technical support and we explain to you how.  



Common Air Conditioner Problems 
that you can Check and Fix Yourself 



Check air conditioner filters to see if they need cleaning


Perhaps the most common problem is one that impacts the performance of your air conditioner in multiple ways, but it is also one of the simplest to check and take care of by yourself.

Within the consequences that a dirty filter can cause are:

  • Low airflow coming from the unit - The more dust and particles that the filter collects, the harder it is for air to pass through reducing the power of the airflow.  
  • Poor cooling when in use - This low airflow can lead to hot and cold spots in the room the air conditioners is being used in because the set air temperature is not able to reach all corners. 
  • Musty smell - The dust and other particles that settle on the filter can lead to unpleasant odours in the room that it operates in.   
  • Overheating unit - when an air conditioner's filter becomes clogged, it must work harder to perform as desired and that can cause it to overheat.  
  • Higher energy bills - Because the filter has to work harder this has a direct effect on the energy that the unit uses, by up to 15%, according to the U.S. Department of Energy. 

Luckily, all of these can be prevented by checking and maintaining the cleanliness of your unit’s filter. For example, with a Hitachi Cooling & Heating residential wall-mounted unit, it is easy to do and can help maintain the performance and reduce the risk of increased energy consumption. 

  1. Make sure the unit is switched off 
  2. Hold both sides of the front panel and gently open it, allowing the panel to swing upwards 
  3. Locate the filters and remove them by pulling them towards you, out of the unit 
  4. Wash the filters using just room temperature water. Using any detergents might cause filter deterioration 
  5. Leave the filters to dry in a shaded place in the house. Exposure to the sun or excessive heat might cause them to shrink. Also, be sure that the filters are completely dry to avoid any issues with mold or mildew 
  6. Once dry, gently push the filters back into place, making sure the 'FRONT' mark is facing the front, and close the front panel 
  7. Turn the power back on and your unit is ready to be used again 

These steps are also included in our article about Air Conditioner Filter Maintenance and the 5 Reasons to Clean it, which you can read here. You can also find information about the best practices for cleaning your filter in the unit’s Operational Manual. 


Have the correct temperature settings been selected?

Though this sounds relatively straightforward, using the incorrect temperature settings can lead to interrupted cooling and heating. This can happen when the air conditioner mode has not been switched from heating to cooling (or vice versa) to match the change in temperature.  

If you’ve checked the temperature settings but the temperature still isn’t as required, make sure that the thermostat isn’t being exposed to direct sunlight. This can lead to exaggerated temperature readings and cause an air conditioner to condition the space it’s being used in ineffectively. 


If during the changing of the season, you find that temperatures are fluctuating and the air conditioner is switching on and off due to changing ambient conditions, opt for ventilation to keep the house cooler.  


Troubleshooting common air conditioner issues and how to fix them


The air conditioner isn’t turning on

Depending on the type of system you have at home and its installation, can you check your power supply? If the system doesn’t show signs of activity and won’t switch on, before calling for technical service, check the breaker box to see if the system has tripped.  


There are various reasons that an air conditioner trips, including operational strain caused by dirty filters. When this happens, one of the first things you want to do check the breaker box and turn the switch to off and then back on again.  


It's worth considering if whether new electrical products have been installed since the air conditioner was last in use and if this is putting a strain on the power being consumed in your home.  


If the problem persists then turn the air conditioner off at the power supply and call technical services to come and inspect the unit before using it again. 


Poor air distribution throughout the space caused by furniture


This is particularly true in the case of homes that have ducted air conditioning systems and making sure that air vents (both return and supply) are open and are not being blocked by any furniture or items. It’s worth investigating as  Pacific Gas and Electric Company reported that blocked vents require up to 25% to distribute the air. 


Covering vents with large pieces of furniture (sofas, cupboards, rugs, drapes) means that the air in your home can’t circulate effectively and the air is getting trapped in the spaces between the vent and item and means that energy is being wasted.  


It is recommended that there are at least 10-inches between the vent and any large items to avoid any issues, this is also applicable to wall-mounted air conditioners, where tall items of furniture can have the same impact on the air flowing out of the unit.  


So, when moving furniture, remember to take the location of your air vents into consideration and check that there is no furniture in the way or that there is sufficient space to allow the air to circulate.  


Air conditioning problem don't block air vents with furniture


These four common issues are simple enough to check yourself but do remember that if the solutions suggested above don’t work or the problem posed is complex, contact our technical support team, who will be able to solve your air conditioner issues guaranteed. 



Issues that require a professional: 


Among the common problems identified, these are the ones that preferably are attended to by a professional instead of attempting to diagnose and solve the problem yourself. 


Checking and cleaning the outdoor unit (ODU)

For some, checking the outdoor unit can simply requires them to go their garden or driveway and double check that there is no plant matter or debris covering or blocking the unit. However, if you are living in an apartment or high-rise building, it is possible that your ODU is on a balcony, on the rooftop or even on wall brackets. In these cases, it is essential that you call a professional to come and check it out.  


One of the signs that your ODU needs cleaning is inadequate cooling inside the home. Just like indoor unit filters, ODUs can suffer from a buildup of dust, dirt and debris and this can impact the temperature that you want to achieve indoors. If your ODU is on ground level and accessible, this is something that you can investigate yourself and see just how dirty the system is. If the cause of the problem is indeed buildup around the unit’s casing, then you can clean it yourself. But if your ODU is attached to the side of the building then it is time to call in the professionals and let them handle it.  


Air conditioner issues with outdoor unit


Your indoor unit is leaking water

This issue is generally a symptom of the drain pipeline becoming blocked with the dust and dirt that flows out of the IDU with the condensation during operation. This can lead to mold and fungus growing, and subsequently catch other particles passing through the pipeline. As this happens, the condensation can’t drain and leads to droplets building up and falling from the IDU.  


This is generally easy to identify on wall mounted units as visible water droplets will gather on the casing. There are other ways to tell if the unit is leaking too. Not only does this cause water to leak from the unit, but it can lead to gasses and bad odors being released into your home, further impacting on comfort.   


A dirty filter could also be the culprit. Why? Because if the air can’t pass through the unit effectively, this means that the evaporator coil isn’t receiving warm air and it freezes. When any moisture in the air hits the evaporator coil, this also freezes, creating ice crystals within the unit, which later melts and can eventually leak out of the IDU.  


The latter problem can be avoided by adhering to decent filter maintenance (as mentioned above) but when your IDU is producing a leak, our recommendation is to contact our technical service team before attempting to fix it yourself.  



How Hitachi Cooling & Heating Can Help


On our website, you can contact us when requiring any sales or technical support by visiting our Contact Us page and completing the online form or phoning our technical support team using the phone number provided.

Our dedicated team and partners are on hand to guide you through the steps that need to be taken to correct any issues. In these cases, Hitachi Cooling & Heating Air Conditioning Error Codes are helpful to diagnose the issue immediately and allow the technician to attend to the correct problem as swiftly as possible.

To learn more about Hitachi Cooling & Heating Error Codes, click here. In this article, you’ll also meet our team of specialists called The Solvers, aimed at HVAC professionals, who explain how to solve a number error codes.  

by Hitachi Cooling & Heating Cambodia