Are There Refrigerant Stop Leak Alternatives for my Air Conditioning System?
February 06, 2018
One of the most popular air conditioning service calls we see involves a diagnostic of “low refrigerant charge”. Well, unless this is a new system and improperly charged upon installation, the refrigerant is leaking somewhere in the system. The system could be leaking in a defective brazed joint or a refrigerant device such as a reversing valve or a thermostatic expansion valve.
We have determined two types of the most common leaks. These leaks are from improperly installed systems, and refrigerant coil leaks primarily in the evaporative coil (A-coil). It is difficult to find small or micro leaks. Electronic leak defectors are a low cost means to find these leaks. The instrument is effective on R-22 systems but less effective on R-410 refrigerant. Electronic defectors are also not as effective on the micro leaks.
The other alternative is the use of system dyes which require a follow trip to scan the system with a UV light at a later date. Some professionals do not want to see any foreign agents introduced to the refrigerant system.
Let’s backtrack for a moment. If your system leaks refrigerant, you need to eliminate the problem by either repairing the leak or replacing the defective component. The EPA (US Environmental Protection Agency) does not like to see you continuously top off the leaky systems. For systems over 50lbs of refrigerant, there is an EPA directive to repair or be subject to fines. Residential systems are usually under this threshold.
Let’s examine the alternative methods used to repair the leaks. The obvious alternative is to find the location of the problem leak and repair or replace the defective part. A brazed joint is a low-cost repair and is a wise decision when easily accessible. However, we see a large number of micro leaks in A-coils. Again, replacing the coil is an alternative, but can cost in excess of $1000 depending on the application.
If the system is older, relatively inefficient by today’s standards, and uses R-22 as a refrigerant, we always suggest the alternative of replacing the system to a newer high-efficiency alternative that uses the ozone-friendly R-410 refrigerant. Many utilities offer system incentives, and through December 31st, 2016, certain systems can qualify for Federal Tax Credit.
However, is there another low-cost alternative? Yes, there is the “stop leak” agents, available from multiple manufacturers. Many HVAC professionals believe entering any agent other than the refrigerant and refrigerant oil into the system is detrimental to the system performance and reliability. Most manufacturers take the position that if they can determine if a “stop leak” is in use, the warranty is void of the price of HVAC equipment. Even though stop-leak additives are not endorsed by OEMS, no long-term studies have been made to determine their effects.
If the leak has the following characteristics, you may want to consider it as an alternative:
- Hard to find leaks
- Leak is not accessible
- Multiple micro leaks
- System is R-22 based and very old
If the economics are a major consideration, the use of “stop leak” agents are a consideration. We always recommend a repair or replace option, but we have successfully used stop-leak in residential systems. However, even though it cannot be guaranteed to work in every application, they can save the customer time, money, and reduced call-backs.