air conditioning engineer cleaning air filters

Why Is My Water Cooled Air Conditioner Not Cooling?

Have you found that your water cooled air conditioner is not cooling as it should? This could be due to a variety of possible reasons. It can be frustrating, especially when it happens on a particularly hot day. This guide will help you determine the root of the problem and what needs to be done to fix it.

Clogged Air Filter

One of the most common reasons that your AC unit may not be cooling is a clogged air filter. These filters catch various dust particles, among other pollutants from your indoor airspace. This dust and debris will build up over time and if left unmaintained can cause your unit to malfunction.

blocked and dirty air conditioning coil being cleaned with toothbrush

Blocked or Dirty Coils

If your AC is not producing cool air, it may be that the coils in your condenser are dirty or blocked. The build up on the coils makes them work harder to absorb or release heat, resulting in a decrease in efficiency. This can also result in an increase in energy costs as the system is using more energy to cool the space.

hand adjusting air conditioning thermostat

Malfunctioning Thermostat

The thermostat reads the room temperature and signals your AC to start or stop cooling. One of the common reasons that your AC is not reaching the temperature it is set to is a dirty thermostat. Dirt and grime can build up on the inside of your thermostat and can cause it to malfunction.

wall mounted air conditioner

Incorrect Size AC Unit

Another reason that your AC is not cooling to your expectation is that the space is bigger than the cooling capacity of the unit. You can check the size requirements by using our handy size guide and cooling calculator. If you find that your water cooled air conditioner is not cooling the required space, you may need a replacement with a higher cooling capacity.

r32 refrigerant gas

Lack of Refrigerant

The refrigerant is responsible for cooling the air flowing over the evaporator coil, which eventually cools the room. Low levels of refrigerant is usually caused by a leak. This means that your AC will not be able to function as needed.

pressure guage

Lack of Water Pressure

Since water cooled air conditioners are plumbed into your mains water supply, water pressure can affect the functionality of your unit. If your water pressure is low, there will not be enough water flowing through the coils to remove heat effectively. This will result in the unit not producing enough cold air to cool the room.

leaking water pipe being fixed

Blocked Water Outlet

Similar to low water pressure, a blocked water outlet can be the culprit behind your AC unit not functioning as expected. Water cooled systems rely on the flow of water to remove heat from the air.

man cleaning air conditioner filters


It is best to contact an air conditioning professional to identify and rectify any issues you have with your air conditioning unit. We would recommend that you do not try to fix anything on your AC system unless you have previous knowledge and experience. This is to avoid any unnecessary damage and repairs costs, especially if your system is still under warranty.

The Importance of Air Conditioning Maintenance

The best way to avoid unexpected malfunctions and breakdowns is to keep your AC unit maintained on a regular basis. This will not only save you money on running and repairs costs but also extend the lifespan of your air conditioning unit, allowing you to get the most out of your investment. It is recommended that you get your air conditioner serviced one to two times a year.

Talk to the Experts

If you find that your water cooled air conditioner is not cooling as expected, we can help. At ACS Installations, we are armed with over 30 years of air conditioning experience. We offer repairs and maintenance services for water cooled air conditioners in and around London at a highly competitive price. Our team of highly experienced engineers offer free consultations so do not hesitate to get in touch. You can reach us on 0208 669 1112 or email us at

Our Maintenance Packages

We offer comprehensive maintenance packages, tailored to your requirements. In addition, we will ensure that your system is in compliance with UK law and that warranty guidelines are met. During our visit we will do the following checks:

  • Leak testing
  • Washing of filters
  • Tightening of terminals and connections
  • Checking of all operations
  • Cleaning of units indoor and out
  • Checking of refrigerant pressures
  • Current checks on components i.e. compressor

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