Why Do Air Conditioners Leak Water ?

Why Do Air Conditioners Leak Water ?

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Why does water leak from air conditioners?

Unless it is a water cooled system, air conditioners do not contain water, although it does generate water condensation as part of its cooling process and whilst this is usually directed outside, sometimes that water can drip from your indoor air conditioner and this can indicate a problem with your air conditioner.


How And Why An Air Conditioner Can Leak Water

As an AC system is designed to either warm or cool an indoor space by moving heat energy from one location to another, it does this by circulating a chemical compound known as refrigerant within the pipework between the indoor and corresponding outdoor unit(s). It is able to move heat energy by using the refrigerant in the pipes to absorb the heat energy and as a result it changes states between being a cool liquid or a hot gas. It is when the refrigerant is in the state of being a gas that it generates water condensation on the outside of the pipework as cools into a liquid. This condensation water drips into a drain pan within the indoor air conditioning unit which collects and directs the water through a pipe that drains the water outside. Ordinarily this water will never be seen inside your home or business as it always is directed outdoors, although sometimes this water can be seen dripping from an indoor air conditioner which not only can damage the air conditioner but its surroundings as well. Common reasons this can happen include;

Common reasons this can happen include;

A Dirty Air Filter From Dust Buildup- A Freezing Evaporator Coil Causing The Drain Pan To Overflow

Whether your air conditioning system has been in regular operation or has not been used for some time, dust and dirt will gradually accumulate through the air vents of an air conditioner and become caught in its filters. As they become increasingly dirty, filters designed to help keep air clean instead start to restrict airflow, restricting heat absorption and causing the normal condensation within the AC unit to freeze instead of being drained outside as it should.

This is especially problematic when the ice melts and creates excess water that is far greater than the air conditioning drain is designed to handle, which will cause water to leak from your indoor air conditioner. This ice build up can also indicate a more serious issue of having an insufficient refrigerant charge within your air conditioning system and this will need resolving as soon as possible.

Clogged Drain Line Caused By Mould – Condensate Water Leakage Due To A Blocked Pipe

Whilst dust and dirt can accumulate in the filters of your air conditioning system, it can also gather in its drain pipework too and worse still it can also promote mould and fungus growth in the standing water, resulting in a clogged drain line.

This is most likely to happen when an air conditioning system has not been used very frequently or properly cleaned during a professional maintenance. When the drain pipe/line is has a clog, the condensation water cannot travel outside and instead will start to leak from your indoor air conditioner. Similarly, if the plastic of the drain pipe is damaged or degraded it will start to leak condensate water intended to travel outside.

Improper Installation – An Air Conditioner That Isn’t Level Can Cause Drain Pan Leakage

If your indoor air conditioning unit was not level when installed, that can also be the cause for water leaking from the air conditioner as the internal drain pan will also not be level and results in the condensation water not being properly collected and instead dripping from the air conditioner.

This is an issue that is not quite as easy to resolve and will require a qualified engineer to correct as well as check for other potentially more dangerous defects.

Health Hazards – Freezing Due To Low Refrigerant Could Indicate A Leak

If the issue is linked to condensation water freezing within the unit, especially if you’ve noticed your air conditioning doesn’t seem to be able to reach your desired temperature and is only producing warm air, there is a possibility your refrigerant level is lower than it should be.

This could indicate a refrigerant leak and exposure to escaped air conditioning refrigerant can be poisonous, so it is highly advisable have the issue investigated by an air conditioning engineer as soon as possible. Additionally, the presence of mould and fungus within your air conditioning system due to a lack of proper cleaning can spread spores and promote the growth of microbes within your indoor space, which can exacerbate or cause respiratory conditions.

Electrical Hazards – Shorts Can Result In Fires Or Electrocution

Water and electricity can be a dangerous combination and water exposure to the electrical components of your air conditioning system are no exception. Recurring moisture can not only result in damage to your air conditioner’s electrics and wiring but ultimately cause an electrical short that can result in a fire.

Accumulated condensate water that is unable to properly drain will also present an electrocution hazard should it reach the live electrical components  in your air conditioning system. If you have any concerns that your air conditioning system may have water damage to its electrics, such as rust discolouration, a burning smell or you believe it is causing your circuit breaker to trip we recommend you contact an electrician immediately.

How does maintenance prevent an air conditioner leaking water?


In order to extend the longevity of  your air conditioner and to ensure your HVAC system remains as efficient as possible for the duration of its lifespan, preventative maintenance includes a series of checks and processes which include actions that will prevent your air conditioner from leaking water that include;


Check and clean air filters – To keep ventilation unrestricted

As ensuring unrestricted airflow is essential to the operation of an air conditioning system, air conditioner filters are checked and cleaned to clear any build-up of dirt and dust.


Check drain lines – To ensure mould and algae isn’t forming a clog

With the drainage pipework being integral to divert condensation moisture away from the air conditioning system so it can be safely disposed of outside, these drain lines are carefully checked during maintenance. Any clogging within the pipework will be cleared and the drain pan sterilised if significant mould build up is found. Some of the pipework may also be replaced if deemed necessary.

Air Conditioner Issues? MAC Offers Free Consultations!

Whether you have home air conditioning or commercial air conditioning for your business that leaks water whenever it is in use, is no longer energy efficient or simply needs professional cleaning on a regular basis, MAC are air conditioning specialists with years of experience working with both residential and commercial properties throughout the Midlands and can offer a range of bespoke maintenance and ac repair solutions tailored to your needs. With an unbeatable track record for the highest standard in customer service and transparent pricing for all professional service and maintenance, our team of HVAC technician at MAC take pride in being honest and upfront with all quotations and advice we provide.

To discuss your requirements or simply ask a question about your air conditioner, contact a professional with MAC’s knowledgeable team a phone call away on 0121 730 4800. You can even reach out to the team via WhatsApp on 07561 570 029  or send us a message to sales@midlandaircon.co.uk for more information on the range of air conditioning services we provide.



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