• SkillCat Team

Causes of Leaks

Updated: 2 days ago

EPA 608 Core Chapter 37 (Take full course for free)


In this module, we will discuss the various causes of leaks and their effect on the HVAC system. Skip to quiz!


1. Refrigerant Leaks


A refrigerant charge refers to how much refrigerant is contained in the system. For example, think of how many ounces of water are in a glass. The amount is typically given in units of pounds (lb).

HVAC equipment needs to be charged with refrigerant in order to operate. If a piece of HVAC equipment does not have enough refrigerant, it cannot work properly. Typically, it will lead to reduced cooling capabilities.


For example, if an air mattress has even a small leak or hole, it will leak and no longer work. Eventually all air may escape from the mattress.


2.Effects of Leaks


A refrigerant leak may mean a harmful substance is released into the atmosphere. This is especially true if we are dealing with CFC or HCFC refrigerants, which deplete the ozone layer.

Refrigerants can also be harmful to humans if it is toxic and leaked indoors.


It’s recommended to check for leaks frequently because leaks are easier to repair when they are small. Large leaks are harder to repair and can cause safety hazards.


Both the repair of a leak and the additional replacement refrigerant will cost money. The cost of both will only increase with a larger leak.

3. Why Leaks Happen


We need to check for leaks before charging a system. Recall that charging means to replenish a system with refrigerant gas.

We find that leaks commonly occur at the following locations in the system:

  • Piping connections

  • Equipment Coils

  • Valves, and

  • Where refrigerant piping enters or leaves a home or building

Leaks can occur for various reasons including the following:

  • Wear and tear

  • Poor initial installation

  • Other construction.

All equipment, HVAC or not, will go through wear and tear. As equipment ages, the possibility of a leak increases. This is just like us humans. As we get older, we’ll go through wear and tear and will find that our back hurts more, for example.


If the equipment was not installed properly to start with, this can cause leaks that may be costly to deal with later on. This is why only licensed HVAC technicians should be working on these complex systems.


And finally, leaks can occur because of other, non-HVAC construction around the system. For example, a nail could be driven into a refrigerant pipe that is located outside the HVAC equipment. This could damage the equipment and cause a leak.


4. Repairing Leaks


If we find a leak in the system, we need to then repair the leak. Finding and repairing the leak will help conserve the refrigerant still left in the system.


Imagine knocking over a full carton of milk. The sooner you stand the carton back upright, the more milk there is left in the container.

This is what we want to do with a system leak. Finding and repairing leaks will help save the refrigerant left in the system.


There can be many ways to fix a leak depending on

  • Where the leak is, and

  • How big the leak is.

One option is to solder or braze the leak on copper piping. If the leak is small and contained enough, you can use this method.


A second option is to replace the component that has the leak (such as a coil).


If the leak cannot be fixed, the entire piece of HVAC equipment may need to be replaced. After a leak is repaired, the system should be checked to make sure the repair is working.


To check the fix, you will

  • Evacuate refrigerant piping

  • Pressurize with nitrogen

Gauges will show if the pressure is holding and if the leak was fixed. If the pressure matches the operating pressure of the system, the system can be re-filled with refrigerant.


5. Conclusion


In this module, we discussed the causes of leaks and learned how to fix them.


Question #1: Which of the following is not a reason why refrigerant leaks are a concern?

  1. They can easily be fixed by all homeowners

  2. HVAC equipment won’t work properly if there is a leak

  3. They can be costly to find and fix

  4. Refrigerants can be harmful to the environment

Scroll down for the answer...











They can easily be fixed by all homeowners


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