AC RepairsAC MaintenanceAir ConditioningDecember 27, 2019by ADKHow to Diagnose & Fix An Air Conditioner Blowing Warm Air

As a business owner who relies on Air Conditioning for the comfort of your staff and customers, it can be incredibly frustrating especially when you find your Air Conditioner blowing warm air. But don’t sweat just yet. 

There are a variety of reasons as to why warm air is blowing out of your air conditioning. AC units are known to regularly require maintenance and inspection checks. When left unserviced it is usual for parts to wear and tear which then lead to a malfunction or even a breakdown. 

Even though your air conditioning system may sound like it’s working, something may be shutting down the cooling mechanism resulting in your AC unit blowing warm air while the fan is operating. We’ll start with the easy issues you can fix, and let you know when you need the skills of a professional to diagnose and repair a larger problem.

If you notice that when checking the thermostat, the temperature is higher than the set temperature then you might want to double-check whether your Air Conditioner blowing warm air by placing your hand over one of the AC vents. If this is the case, the warm air is likely the result of a combination of issues or a refrigerant leak.

Before you call in the HVAC experts, we have created this guide to successfully identify the cause of the issue and how it can be resolved.


Thermostat Settings

The first thing to check is the thermostat which is easy to do. If thermostats are constantly tampered with by staff the desired settings may have been changed leading to higher indoor temperatures. Ensure the thermostat is set to COOL and the fan set to AUTO. 

Once this is done, double-check that the temperature set is actually lower than the air temp. Even at the correct settings, the thermostat may fail at assessing the temperature and therefore communicate ineffectively with the control board. If this is the case it is best to call in the AC engineer to fix or replace your AC thermostat.


Dirty Air Filter / Coils

A clogged air filter will result in reduced airflow which is one of the most common issues faced by air conditioners. The AC’s filter is designed to remove dust and contaminants from the air collected and distributed, however over time it can become clogged whereby debris can completely block air from entering the AC system. When this happens the condenser coils are unable to remove the heat leading to your units fan blowing out warm air.

Related article: How cleaning your AC coils can save you money .


Damaged or Leaky Ducts

Another reason as to why your AC unit may be blowing warm air may be related to your ducts. As the cooled air supply tries to make its way back to the unit it could be affected by disconnected or ducts with holes or cracks, negatively impacting the circulation of return air. This will lead to the AC blowing warm air as a result. 

Any holes or tears should be sealed up as soon as possible to ensure your air cooling system works efficiently. If accessible, we advise checking all your AC ducts to assess for damage. However, due to the nature of how some AC systems are installed ducts may not be visible and hidden in the ceiling which will require you to call out the experts. They will be able to provide you with a full system health check, which will save you money in the long-term.


Refrigerant Leaks

The most common cause for AC units to malfunction is a leak in refrigerant. Refrigerants can leak for a variety of reasons from a loose joint, heavy use during the winter or even poor assembly during installation. Refrigerant is the substance that flows through your air conditioning system and aids cooling. 

During a leak, your system loses refrigerant charge and cooling power. Depending on the type of leak, cooling loss can either happen slowly over time or happen all at once, thus leading to the inability to generate cool airflow and resulting in blowing warm air. It is important that no further refrigerant is added without identifying and fixing the leak beforehand. 

We advise calling in the HVAC professionals to correctly diagnose the location of the leak to correctly and safely resolve the issue with refrigerant leaks. By undertaking some basic housekeeping tasks and signing up for a PPM contract you can protect your investment and ensure that you are always getting the best performance out of your commercial air conditioning units. 

At ADK, planned preventative maintenance visits can be arranged with clients tailored to their personal requirements within a timescale to suit their business needs and budgets. Tailoring our works for minimal disruption to your schedule, we’ll ensure that your refrigeration unit is maintained and that your cooling system is always working to the best of its capabilities, as efficiently as possible.

For more information about our HVAC services, please get in touch with us today or call 0208 831 8900 and we’ll be more than happy to help you with anything you need. Alternatively, you can contact us to request an engineer and a free site survey.

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