HVAC systems have intricate parts, a lot of electrical and moving pieces. However, one of the most complicated aspects is the refrigeration system is detecting a leak. A refrigerant leak can happen at any point along the line and can be one of the most challenging things to find.
Diagnosis isn’t all you have to worry about. Fixing a leak and repairing a system are only accomplished through skilled labor with precision tools. Along with a high-quality set of HVAC gauges, the best refrigerant leak detector will ensure you do the best job possible.
Quick Guide – Our Top Picks
How HVAC Leak Detectors Work
There are various types of leak detectors on the market, and each one has a particular way of detecting a leak. In the most basic principle, leaks make noise, set off vibrations, and can produce electrical currents.
The various leak detectors take advantage of these aspects and make what can be inaudible, invisible, or undetectable to human senses, easily located. The principle behind each method is discussed later in this review. Each, with their pros and cons, can be useful for the HVAC technician or knowledgeable homeowner.
Benefits of a Reliable Refrigerant Leak Detector
Leaks in your HVAC refrigerant system can be as hard to find as the proverbial needle in a haystack. The major advantage of owning your own refrigerant leak detector is that it will act as your needle searching magnet. It makes short work of leak detection.
Because leaks can be small, their hissing sound can be inaudible. A leak detector specializing in ultrasonic vibrations can make them audible to the human ear. Sometimes, a system will be compromised and have multiple leaks throughout the entire system.
With a leak detector in your arsenal, you can find your problems, repair them and make sure you got them all. Repairing a leaking system can save you time, money, and frustration, some of the best benefits you can ever ask for.
HVAC Refrigerant Detectors Compared
HVAC Refrigerant Leak Detector Buying Guide
Before you plop down your credit card and enter the numbers on the order form, there are a lot of factors to consider. Let’s cover those now.
Durability
Obviously, you will want your investment to last. While regular care and maintenance go a long way, so does the build quality. Having a rugged detector will protect itself against an accidental drop, water damage, or oil seepage.
If you are going to spend your money on the best refrigerant leak detector, you will want to protect that investment. Part of that protection is to purchase a model that can protect itself.
Variety of Refrigerants
There are currently over 75 different types of refrigerants in use around the world. There are very few detectors that work with all refrigerants, so you should focus, instead, on the types of refrigerants you work with.
For example, professional users may come in contact with R-22, R-12, R-401a, R-134a, and a few others. Homeowners, on the other hand, may only find a use for R-410a or the out-dated R-22. While it may seem ideal to find the biggest model that covers the most uses, you don’t need to pay for something you will never use.
Detection Type
There are four types of detection that these leak detectors can use. Knowing how you will use the detector will help you determine which one to buy.
You can choose from ultrasonic, infrared, corona discharge, or heated diode. I will explain the differences further into the review. What you do need to know is that different detection methods will yield different results. Knowing the type of results you want will go a long way to making your final decision that much easier.
Leak Sensitivity
Leak sensitivity levels are the cornerstone of how well a particular device will perform. Leak sensitivity is basically the idea of the level of detection capability. The higher the sensitivity, the smaller the leak can be and still get detected.
Each type of detection has a limit on sensitivity, and it is important to note these levels. Professionals will require more sensitive equipment than a DIYer, for example, but both should know what these ratings are.
Efficiency/Speed
The efficiency of the leak detector is generally measured in how fast it can find a leak and give you the needed data for a repair. Since refrigerant can be expensive, locating and repairing the leak quickly will save money. It can also save time and prevent further damage, or the leak from getting worse.
Long Battery & Sensor Life
Battery life is going to come into play as well. You don’t want to find yourself in the middle of a job and have to stop for an hour to recharge your equipment. If you can’t find a model with decent battery life, the alternative is either replaceable batteries or a fast charger.
Sensors will have life spans, too. You should know what the average life expectancy of the sensors is and have a backup plan for when yours is suspected of wearing out.
Ease of Use & Maintenance
Being comfortable right from the start is a bonus. An easy to use detector can go a long way to lowering that learning curve.
Cleaning, care, and mintenance of your HVAC leak detector are crucial.
You will need to make sure the sensors are in good working order, no contaminants have made their way into the sensor areas and that it remains clean and charged. Some models make this easier than others.
So it is best if you know the process before you buy, so you know what is asked of you.
Price & Warranty
Your budget is a factor, as well. While you may want the biggest, most expensive model out there, it isn’t always feasible. Staying within your budget will make the investment that much better. Especially if you don’t plan to use it all that often.
Daily use, or in a contractor’s bag ready for daily use, might warrant jumping up a tier on the price range, but for the most part, just because you pay more doesn’t mean you will get more.
Look at the warranty as well. It will tell you what is covered, how long it is covered for, and, most importantly, what you need to do to retain the warranty. Make sure you follow all the parameters required, whether that is registration, keeping proof of purchase, or taking pictures of the model and serial number.
All of these things will make the claim process much easier; should you decide to make one.
8 Best Refrigerant Leak Detectors Reviewed
Now it is time to unveil my findings. After a lot of research and testing and listening to owners’ complaints and commendations, I bring you the 8 best refrigerant leak detectors, reviewed, and compared for your convenience.
1. Fieldpiece Heated Diode SRL8
Our Top Pick For HVAC Technicians
| Leak Detector Type | Heated Diode |
| Refrigerants Detected | CFCs, HFCs, HFOs, and Blends/Mixes |
| Battery & Sensor Life | 15 hrs battery/100 hrs sensor |
| Detection Speed | Fast |
| Sensitivity Levels | 3 Levels |
| Warranty | – |
The Fieldpiece SRL8 is our top pick for HVAC technicians. This little box is one of the best on the market overall, and for the professional can be a time saver. The heated diode detection system is ideal for a trained professional. Since the learning curve is a little high, it isn’t designed for the DIYer.
This doesn’t mean only pros can use it, but for the novice or once-in-a-while use person, there are better options available. The SRL8 will detect a wide range of refrigerants (some better than others), including CFCs, HFCs, HFOs, and their blends.
The lithium-ion battery pack will run 15 hours from a full charge giving you ample time to locate that leak. It does take a couple of hours to recharge, though, so keep that in mind when you are running from job to job.
The diode does need to warm up before it can be used to detect refrigerant; however, this takes less than a minute. Unlike other models that can take a full two minutes or more, the SRL8 is ready to go when you get to the HVAC system.
It will also auto-zero to help eliminate false positives and reduce contamination build-up. Every two seconds, the readouts will return to zero. Once you find your leak area, you can move to a manual zeroing, which will help you identify a more exact location.
Pros
- Auto-zero for easier tracking.
- Battery can be recharged or run from AC adapter or 12v car adapter.
- 30-second warm-up.
Cons
- Diode can result in a lot of false positives.
2. Robinair 16455 TruTrack
Top Of The Range Model
| Leak Detector Type | Ultrasonic |
| Refrigerants Detected | Any |
| Battery & Sensor Life | Up to 96 hrs battery/5+ years solid probe sensor |
| Detection Speed | Medium |
| Sensitivity Levels | Adjustable turn-dial |
| Warranty | 1-year on all parts but battery. |
When only the best will do, the Robinair TruTrack is ready to go. The TruTrack is an ultrasonic detector that will detect all refrigerant types. It doesn’t stop there, though; you can also hear vibrations from failing bearings, valves, and seals and almost any engine component.
The main issue with an ultrasonic detector is that you must wear headphones to hear the audible hissing. On top of that, the ambient noise int eh environment needs to be quiet as well. If you are looking for an R-134a leak in a car, for example, a noisy working garage may not be the best option.
Aside from that, everything is made easier with this device. You can dial up the sensitivity and begin detecting leaks from a few feet away. As you get closer, you can dial down the sensitivity level to help you pinpoint the location. Follow that with a quick soap bubble test, and you are ready for repairs.
The TurTrack has everything you need, including the solid probe, flex tube, carrying case, and one of the most complete and authoritative manuals on leak detection I’ve ever seen. If you are serious about leak detection and need something capable of more than just refrigerant leak detection, you can stop looking.
Pros
- Everything you need is included in package.
- No warm-up time needed.
- Can be used for any air leaks, bearings, seals, or other system components.
- Huge, detailed manual included for use and learning.
Cons
- Must be quiet environment to hear leaks, even with headphones.
- Detection range varies from inches to feet.
3. MASTERCOOL 53351-B
Best UV Refrigerant Leak Detector Kit
| Leak Detector Type | Infrared/UV Dye |
| Refrigerants Detected | CFCs, HFCs, and HFOs |
| Battery & Sensor Life | N/A |
| Detection Speed | Slow |
| Sensitivity Levels | None |
| Warranty | 1-Year limited warranty |
If you are a mechanic that works on AC systems, the MASTERCOOL 53351-B is the ideal leak detector for you. It comes with everything you need, including the dyes and dye remover. The safety glasses aren’t stylish, but they are UV and safety rated, so you won’t need to wear anything else to stay within OSHA standards.
The kit includes the UV mini flashlight that will illuminate the dye when it leaks out. It comes with alligator clips for connecting to the car battery, so you don’t need to worry about recharging battery packs or finding a nearby outlet.
However, with this setup, it isn’t designed for home use. Unless you want to carry around a 12-volt car battery to every job site, residential HVAC detection should come from somewhere else.
You will also need to consider that the dye is a limited supply and cannot be reused, so you will need to make more purchases to replenish the dyes at some point. The extra cost is minimal, but it is worth reminding you about.
Beyond that, the detection is easy to use. Add the dye to the AC lines and let it run for about 10 to 20 minutes. The dye will mix with the refrigerant, and when it gets to the leaking area, it will spew out. The dye will coat the tubing, and anywhere else it comes into contact with.
Using the UV light and the glasses, you will be able to spot exactly where it is coming from. Once you have made the repairs and stopped the leak, you can use the included dye remover to get the dye off of the metal, your clothing, skin, or almost any other surface type.
Pros
- Simple system to use to detect R-134a leaks in automotive AC systems.
- No other parts or equipment needed to use.
- UV rated glasses are safety rated.
Cons
- Designed for working only on vehicles.
- Will require dye replenishment.
4. INFICON D-TEK Select
Best Infrared Refrigerant Leak Detector
| Leak Detector Type | Infrared |
| Refrigerants Detected | CFCs, HFCs, A2Ls |
| Battery & Sensor Life | 10 hrs battery/ 800-1000 hrs sensor |
| Detection Speed | Moderate |
| Sensitivity Levels | 2 Levels |
| Warranty | 2-year warranty on parts and craftsmanship. |
Are you looking for an infrared leak detector? INFICON has the best electronic refrigerant leak detector available. The D-TEK Select is an infrared sensor with an overly simple interface. It comes with a rechargeable battery pack that will last you about 10 hours on a full charge.
You also get sensor filters, which saves you time and money down the road. The sensor itself is quite impressive, though. Designed to outlast any other infrared sensor on the market, the D-TEK Select sensor lasts up to 1000 hours before needing replacement. Of course, this depends on your care and maintenance routine. Changing the filters regularly will prolong sensor life.
There are two sensitivity settings to choose from. When you use the high setting, the sensor will detect a broader scope of the leaking refrigerant. With practice, this can get you to within a few inches of the leaking area.
From there, you can switch to low sensitivity to get a more accurate sample area size. Depending on the leak, you might still need to use the soap bubble test to verify you are in the right spot.
The two-year warranty will cover the INFICON refrigerant leak detector, sensor, probe, and battery. The filters are not included with the warranty, and any sign of neglect or abuse will void the warranty as well. Maintenance is simple enough to complete, and regular inspection, testing, and cleaning should be carried out to ensure a properly working unit and loner life expectancy of the sensor.
Pros
- Designed to only detect refrigerants.
- 800 to 1000 hour infrared sensor life.
- User-friendly interface.
Cons
- False positives are common
- Skill needed to find exact leak area.
5. Elitech WJL-6000
Best HVAC Freon Leak Detector
| Leak Detector Type | Corona suppression |
| Refrigerants Detected | CFCs, HFCs, and HFOs, Blends, A2Ls |
| Battery & Sensor Life | 50 hrs batteries/ 24 hrs sensor |
| Detection Speed | Fast |
| Sensitivity Levels | 7 Levels |
| Warranty | 1-year replacement warranty |
The Elitech WJL-6000 is the best HVAC Freon leak detector around. Using corona suppression detection methods, the simple to use system makes short work of finding your leak location. It will require a bit of training and practice to get the system to pinpoint the leak. In the meantime, though, you can use the soap bubble test when you have narrowed the area down.
This detector is ideal for homeowners, professionals, and mechanics. It will detect most refrigerants, including A2Ls. The WJL-6000 is easily the best leak detector for R-410a. The one downside is that the sensors don’t last very long (about 24 hours rated, 18 hours tested).
You get a long, 8-inch probe to dig around in hard to reach areas and both audible and visual alerts when a leak is detected. False positives are bound to happen as dust, air, and other contaminants can set it off. However, the siren is structured so that only constant flow will set the tone off to determine a leak.
This means that while the alarm may sound, it will only reach the high-pitch siren when the system has detected a consistent flow of Freon. Jut be warned, that this siren can get pretty loud.
Pros
- Super-fast warm-up period.
- Audible and visual alerts.
- Adjustable sensitivity dial can be used while searching.
Cons
- Siren alert can get quite loud.
- Sensor life is quite short.
6. Elitech CLD-100
Best Cheap Refrigerant Leak Detector
| Leak Detector Type | Corona Suppression |
| Refrigerants Detected | CFCs, HFCs, and HFOs |
| Battery & Sensor Life | 10 hrs battery/ 22 hrs sensor |
| Detection Speed | Fast |
| Sensitivity Levels | 6 Levels |
| Warranty | 1-year replacement warranty |
The CLD-100 from Elitech is an upgraded version of the WJL-6000 mentioned in the spot above. It is the best cheap refrigerant leak detector on the market. Not only will you save money with this model, but it does exactly what it says it can.
You do get more false positives with this model, and the sensors don’t last quite as long. However, it is smaller and more agile and has a better chance of pinpointing your leak source.
The familiar turn-dial sensitivity has 6 levels to help you narrow down your search area quickly. And, should anything go wrong during the first year, Elitech will replace the unit for you. Make sure you maintain your proof of purchase to make a claim, though.
The CLD-100 doesn’t do so well with A2L’s, but for residential and commercial refrigerants, it won’t be a problem. You will find most CHCs, HFCs, and HFOs are easily detected, and in less than 3 seconds, you can have an alert.
One downside is the small size. While the probe is flexible, you may find it challenging to get into tighter areas than the model listed above. Smaller hands will have an easier time with this version, though, and for most applications, the size won’t be a factor.
Pros
- Active for sensing in less than 6 seconds.
- Halogen corona has less false positives than the WJL-6000
- Ideal for DIYer and homeowners.
Cons
- Flexible probe may be too short.
7. UView 499008 Universal
If you are looking for UV dye for your infrared or UV detection system, UView is where you need to put your money. Hands down the best refrigerant leak detector dye on the market, UView won’t let you down.
This 8-ounce bottle uses a unique “shot glass” style pour system that measures out 32 doses when needed. Adding to the AC system is simple and effective. Once it makes its way through the low and high-pressure sides, you will see results in minutes.
Most often found in mechanic shops and garages, the Homeowner and DIYer can use the universal fluid, too. It can work in any AC system and will pinpoint the exact leak spot. You won’t have to guess or use any other detection methods after adding UView.
It doesn’t wash out of clothes or off heated metal as well as some others, but this is the only downside I can find to say about this dye. When used correctly, it won’t fail you, unless, of course, there isn’t a leak to detect.
Pros
- 32-measured applications from unique pour spout.
- Works in all AC systems.
- Includes service stickers.
Cons
- Can be hard to detect in sunlight.
- Higher cost for 8oz bottle.
8. Nu-Calgon 4182-24
Don’t mix dish soap and water for your soap bubble tests. You can, of course, unless you are working in an area that is cold, has food nearby or want iffy results.
Nu-Calgon’s Cal-Blue Plus is safe to use in food working areas and has a super low freeze point. It won’t matter if you are in the walk-in cooler or the beer shed, the bubbles will form down to 5 degrees. It is easily the best AC leak detector spray available.
You can take all the guesswork out of leak detection and pinpoint your leak spot in minutes. Served in a 1-quart bottle, you only need a couple of squirts to make bubbles. This is ideal for any mechanic or HVAC pro that relies on leak detection for their work.
Use in combination with an electric detector, and you will have your leak found, repaired, and forgotten before the other guys fill their soap bottles.
Pros
- Safe for food space applications.
- Takes all guesswork out of leak detection.
- New formula bubbles more easily.
Cons
- Runs off too quickly from frozen pipes.
4 Types of Refrigerant Leak Detectors
As I mentioned earlier, there are four types of refrigerant leak detectors. Each one has its advantages and disadvantages. Let’s take a moment to learn about the different types.
Corona Suppression
Also known as Negative Corona, these are electric sensors, much like a heated diode (see below). The core sparks to make a corona, and the alarm is triggered whenever the leaking refrigerant breaks the corona.
This is one of the oldest methods of leak detection around, and it is highly susceptible to dirt, dust, air and water contamination, and false positives. When it isn’t contaminated, though, it is highly accurate and quick.
Heated Diode
There are certain chemicals, such as refrigerant and coolant, that react with a hot ceramic diode. The reaction creates an electrical response that is detected by the diode and transmitted to the detection unit that will alarm or alert you of a leak.
While this is one of the more common types of refrigerant leak detection, it is also the method most capable of false readings and missing leaks, since waters and oils can interfere with the electrical current created.
Infrared
The camera will monitor the heat signatures of the pipes, surrounding equipment, and ambient air.
When the hotter (or colder) leak comes into view, it will light up on the camera like a spotlight, allowing you to mark its location for repairs.
The tricky part of this is having leaks in areas the detector can’t get to, such as the underside of a pipe or in an area where the house framing is in the way.
Ultrasonic
In general, smaller diameter holes and high-pressure refrigerant will hiss or squeal. The problem is that a large percentage of the time, the human ear cannot hear this hissing sound. Ultrasonic leak detection works by lowering the frequency range. This allows your ear (with the help of headphones) to hear the hiss and mark its location.
The main problem with this is like the infrared, it can be challenging to get to certain spots, and you need to be right on top of the leak to find it.
Alternative Methods
There are a few other methods that don’t require dedicated equipment. You may find them useful for more prominent leaks, but they don’t always work, so use them at your own risk.
- Soap Bubble Method:
This is your basic leak finding method. Used by mechanics for decades to find air leaks in tires, you mix a small amount of soap (liquid dish soap works best) in water and spray the suspected leaking area. Around the fill valves, Schrader valves, caps, and elbows are common areas.The idea is that the soap mix will go into places you can’t easily see or listen for a leak. The soap will cover the hole, and the leaking refrigerant will cause the soap to make bubbles. The main problem here is that if the leak is active, it can produce so much pressure that the bubbles get popped before they form big enough for you to see them. - Ultraviolet Dyes:
UV dyes are another common mechanics tool for leak detection. There are two methods for application. The first is that you add the dye to the system through the Schrader valves and let the dye mix with the refrigerant and run for a while. As the dye circulates, it will spew from the hole, and you can detect the location by using a black light and viewing where the dye appears.The other method is a physical application of the dye to the outside of the system, rubbing pipes, fittings, and dryers. The leak will cause the dye to spread or dissipate, and through the use of black light and goggles, you can spot where the dye isn’t uniform.As you can see, UV dyes can be highly accurate but difficult to implement.
Signs & Risks of Refrigerant Leaks
Several risks go along with a refrigerant leak. The first, obviously, is that your air conditioner won’t cool properly. The low levels of refrigerant can also lead to compressor burn-out, start fires, and cause more system parts to fail, requiring replacement or hefty fees for repairs.
The first sign of a leak that you may notice is frozen pipes. If you look at the copper piping leading from the house to the condenser unit outside, they will begin to ice over. The longer the leak continues, the more ice will show up. This can eventually encase the entire compressor, the lines through the walls and the evaporator unit.
If the evaporator gets iced over, when the system shuts off, the ice will melt and flood your floors, walls, and fixtures. You will also notice that the air isn’t blowing as cold as it should be. While both of these common symptoms can also point to other factors, a leak is the most likely culprit.
How to Use Refrigerant Leak Detectors
When you use a refrigerant leak detector, it takes a bit of skill. The most important thing to keep in mind is that they are designed to get you close, but may not be able to pinpoint the exact area of the leak.
All detectors will have a tip that needs to be tightly secured in place. An alarm may sound if it is loose, and if it isn’t snug-tight, you can increase your likelihood of false positives.
Once everything is verified to be working correctly, turn the unit on and set the sensitivity to its highest point. This will be a broad sweep of the suspected leak area. Once you get an alarm, you can minimize the sensitivity to narrow down the location further.
You will want to test the area a few times to make sure you aren’t getting a false positive and then follow that up with a secondary test, such as the UV or soap bubble test mentioned earlier. This will bring your focus to a specific area, and repairs can begin.
Care, Maintenance, & Troubleshooting
For the most part, these devices are maintenance-free. You will have to maintain fresh batteries, or charge as well as keep the tip clean.
All tips will wear down after some use and need to be replaced. Depending on the type of tip, detector, and frequency of use, this time frame for replacement will change. Refer to your specific model’s owner’s guide for recommended replacement intervals.
Cleaning the unit is simple as well. A damp cloth to wipe off the casing and face, as well as a clean, dry cloth to remove any leftover moisture. Make sure the tips stay clean at dry at all times.
Troubleshooting is also reasonably straightforward. Almost every problem with the unit will be because of dead batteries, a loose tip, or a worn-out tip. Replace with fresh batteries, and if the problem persists, move to troubleshooting the tip. Make sure it is tight, and replace it with a new one. If problems continue after that, you may need to replace the unit.
Frequently Asked Questions
What does a refrigerant leak smell like?
Refrigerant does have an odor, but it is faint unless in high quantities. You may small nothing at all, or you can get occasional whiffs of a sweet, chemical type odor.
What type of refrigerants will my device be able to detect?
Most detectors will be able to detect leaks of all major types of refrigerants. While specialized detectors are designed for refrigeration used in HVAC, automotive, and small appliance settings, others will detect any of the fluorocarbons. CFCs, which are rare now because of their harmful impact on the environment, are the original coolants used in HVAC systems. HFC replaced these because of their much lower impact on our health and the environment. Most detectors will capture all of these types of refrigerants. Newer models are also capable of detecting HFOs, or HydroFluoro-Olefins, have an even lower impact and are rapidly replacing automotive refrigerants (R-134a) and appliances like refrigerators and window AC units.
How long does it take for freon to leak out?
Refrigerant can leak out of the system in a matter of minutes, or it can take months. Depending on a lot of factors, including elevation, ambient temperature, and barometric pressure, if the system is running and where the leak is located. For example, a worn Schrader valve in the fill port with an air cap tightly in place can take a few months to leak out enough to cause issues. On the other hand, a pinhole leak on the high-pressure side of a copper supply line can leak out of a running AC in a couple of hours.
What’s the best way to find an AC leak?
A mixture of detection methods is best. Using an electronic detector will help you narrow the search area tremendously, and can get you within a few inches. From there, the soap bubble test or UV test is needed to pinpoint the exact area of the leak (unless the leak is significant and can be heard or felt without instruments).
Is a refrigerant leak dangerous?
Refrigerants are non-flammable by nature. However, they do pose a threat to the other parts of the HVAC system. Low levels of refrigerants can cause overheating, which can arc to nearby drywall, insulation, or wiring, which can start a fire. The refrigerant itself is harmful is inhaled or ingested and can cause frostbite when exposed to skin.
Conclusion
The best HVAC refrigerant leak detector for you is going to be the one that is easy to operate, will detect the refrigerants you will be working with and is useful, durable, and reliable.
Any of the options on the list in this review article will help you locate any number of leaks. Picking the right one, however, is a judgment call on your part. Find the model that fits your budget and has simple controls that you can master easily. If you are in doubt, go with our top pick, the Fieldpiece SRL8. It will serve you well, is easy to maintain, and can be used right out of the box.
