What are the Best Refrigerant Leak Detectors?

No HVAC tech is complete without a refrigerant leak detector. I don’t care what part of the world you are in this is a tool that you will use and use often. The question though is what type of leak detector to use, what brand to buy, and what to look for when purchasing. Finding and identifying a leak for your customer is an extremely important task. Even more so if your customer is a business or at a plant. Depending on the size of the refrigerant leak your customer could be facing fines from the Environmental Protection Agency of up to twenty-five thousand dollars a day on a leaking unit and that isn’t even mentioning the potential cost to their business of having their refrigerated unit down. So, when you get the call from a stressed or angry customer you want to show up with the right equipment and the right knowledge to get the job done.

The Three Types of Leak Detection

There are three modern types of finding and identifying leaks in your unit. I am sure most of you are familiar with them by now but I wanted to reiterate before we get into what considerations that should be taken when purchasing a refrigerant leak detector. Let’s start with the simplest and move our way up.

  1. Soap and Water – While this may seem overly simplified I can assure you that sometimes simple is best. Keep it simple stupid. You apply the soap/water combination to the suspected leak points and then in theory you should begin to see bubbles form where the refrigerant is leaking out of the unit.
  2. Ultraviolet Dye – Ultraviolet dyes are a great way to diagnose leaks but they should be used sparingly. Too much dye used in a system can affect performance and may end up damaging the unit. Not to mention that if you wind up using a dye that is not compatible with your compressor’s oil you could cause damage to the compressor and shorten it’s life. If you plan on using dyes please do your research.
  3. Electronic Leak Detectors – Leak Detectors are known for being exact, sometimes too exact. While this is a great thing to be known for it can also be extremely frustrating as you have to get close enough to the leak for the sensors to work. You could end up sniffing around and finding nothing even though you know that there is obviously a leak somewhere on the unit.

The thing to keep in mind when looking at the above ways to detect leaks is that there is no best or perfect solution. Depending on your situation and the job at hand the type of leak detector may vary wildly or you could even end up using a combination of the three. Perhaps use the sniffer to narrow down your search and then apply the soap and water solution.


As with any type of tool that you purchase you should always take in certain considerations before you purchase. Is it the right tool for you? Is it going to last? Is it going to accomplish what you need it to? Let’s take a look at some of the considerations to be made when looking at refrigerant leak detectors:

Types of Leak Detectors

First and foremost we should identify what kind of electronic refrigerant detector you want. Now there are two main types of detectors and they are: Corona-Suppression and Heated Diode. The corona-suppression type works by creating a high voltage corona in the sensing tip. When the corona senses refrigerant the device will sound an alarm. This type of leak detector is the oldest type and some models go all the way back to the sixties. (Yes that far!)

The second type of leak detector is the heated diode. This type of detector works by heating the refrigerant and breaking the molecules apart. When the molecules are broken a positively charged Chlorine or Fluorine ion will appear. The heated diode will detect these ions and sound the alarm. The downsides to both of these types of detectors is that they can be overwhelmed if the refrigerant leak is too large. If the area is saturated with refrigerant then these alarms won’t be of much help.

Now, there is a third type of detector that has been around for a while now called the ultrasonic detectors. These detectors work not by detecting refrigerant but by detecting the noise the refrigerant would make when it is being leaked. When refrigerant is leaking out of a unit, hose, compressor, or whatever it creates an ultrasonic sound that is so high a human ear cannot hear. The best thing about this type of detector is that it reacts by pressure and not by volume of refrigerant. The downside of this type of detector is that at times it can detect other noises that are around you and that are not coming from the unit you are working on. This could be especially troubling when in a large commercial building or plant environment with other machines going on all around you.

What Kind of Refrigerant Will it Detect?

Ten years ago this may have not even been an issue as most leak detectors were outfitted for detecting the standard CFC, HCFC, and HFC refrigerants. There were a few out there that weren’t yet outfitted yet for R-410A/Puron but for the most part your leak detector could sense them all. The concern that I have now is that a lot of the leak detectors out there today may not be able to detect all the kinds of refrigerants on the market today, especially the newer HFO refrigerants.

Another thing to consider is if the leak detector you select will be able to detect blends of refrigerants. So many refrigerants nowadays are comprised of multiple blends and mixes in an effort to get their flammability down, get their GWP down, and to allow for easy retrofitting or for drop-in replacement.

The Speed of Leak Detection

For those of you who have used an electronic leak detector before you know how finicky and picky they can be when trying to find a leak. If you’re outside and the wind starts blowing you could have your alarm go off. Another common issue if there is too much refrigerant in the area. Some sensors can be overwhelmed by the volume of refrigerant if there is a large leak. If the area is saturated with refrigerant then your detector may not know the difference and may either sound off constantly or get to the point where it doesn’t detect anything due to the saturation.

Length of Use – Batteries

Another thing to consider how long your unit will last in the field. How many batteries does it take? What kind of batteries? I have seen some units that last only three to four hours of continuous use while others last for a nearly a day. I have also seen some detectors still run and drain the batteries even as they are sitting on the shelf in your garage. Some users have ended up taking batteries out before putting it away or by carrying a few extra sets of batteries with them just in case they have a dead unit when they are out in the field.


Durability can amount to a few things. The first being the unit itself. How long will it hold up over the years? Will the alarms and controls still work? Most of the time the actual electronic detector will be fine over an extended period of time. What we have to look out for is the sensor. Depending on the product you buy you could have a sensor only last for fifty hours of use or you could have one last for over one-thousand hours of use. It all depends on quality. Keep in mind also that sensors can usually be replaced so if it does go out it’s not a huge deal.


This is a given and is what most people consider first when looking to purchase something. Do I buy the cheapest thing out there or get the premium? Remember though, you get what you pay for. Detectors can range from twenty to thirty dollars all the way up past two-hundred dollars.


The last point I want to make before we get into the products is the warranty. Say you get your detector and after six months the thing goes kaput. What options do you have? Do you know your warranty? Does your product come with one of those thirty-day tags, a one-year, or perhaps even a lifetime warranty? This is definitely something worth reviewing before purchasing.

Good, Better, Best Approach

When I do a best of article I always like to use the Good, Better, Best approach. What is that? Well it is something that one of my former bosses told me years ago and that has stuck with me forever. If you give people too many choices they will become overwhelmed and eventually shut down or walkaway.  The Good, Better, Best approach focuses on only three product offerings. It takes away the overwhelming choice and instead gives you a pick based on your budget. If you are one of those guys looking for the cheapest, but still good, product then the Good is for you. If you are one of those middle of the road guys who wants to spend a bit more for a better quality product then I would recommend the Better choice. However, if you are a premium buyer whose money is no object (Wouldn’t that be nice.) then I would recommend spending your money on the Best and getting the highest quality product. The question you should ask yourself is what kind of consumer are you? What type will you go for?


Signstek Portable AC Refrigerant Halogen Gas Leakage Detector

Signstek Portable AC Refrigerant Halogen Gas Leakage Detector Tester with High Sensitivity for Home UseCheck Price on Amazon

Coming in at our Good category is Singstek’s refrigerant leak detector. The Signstek is a negative corona type leak detector as we discussed above. This one of the oldest and one of the most reliable types of leak detectors on the market today. There’s a reason this type of detector hasn’t changed much over the decades. It works.

This unit is set at a bargain price and will be a great buy for a tech just starting out in the field or for a business owner  looking to gather a collection of tools for their techs. This model detects halogenated refrigerants which is nearly every type of refrigerant on the market today. You will be able to detect R-12, R-22, R-502, R-410A, R-134a, and R-404A. (There are more but I won’t list them all.) It is important to note that this detector will not work on hydrocarbons such as isobutane or propane.

The sensor on this product will last for more than fifty hours of continuous use. While that may not sound like a lot of time you should note that most of the time you’ll be using your detector for five to ten minutes at a time trying to identify a leak. Fifty hours is quite a bit of time and when your sensor does bite the dust you can always purchase a replacement. You also get a spare sensing tip with purchase of the unit.

Now since we are at the Good category here this isn’t the perfect tool. Users have stated that the sensitivity is near as high as they would like. Users may spend more time then they are used to sniffing around for a leak. Especially if the are used to a higher quality detector. You will also have more false positives on this unit than a premium one, but again you get what you pay for. Most users state that this unit is great for finding the big leaks but if you’re dealing with a micro fracture somewhere in the condenser or elsewhere than this product might not be for you. When I did my research on this I found that most of the consumers were homeowners rather than seasoned technicians. That should tell you something.

If you are on a budget and looking to get a good leak detector than this is your guy. However, if you’re looking to spend a bit more and save yourself some time and frustration then I suggest you continue reading on to the Better and Best categories…


Inficon TEK-Mate 705-202-G1 Refrigerant Leak Detector

Inficon TEK-Mate 705-202-G1 Refrigerant Leak Detector, R22, R410A, R134A DetectsCheck Price on Amazon

I am more than happy to say that Inficon’s Tek-Mate’s 705-202-G1 leak detector is our nomination for the Better category. I can’t say enough about this product. The 705-202-G1 is a heated diode type of detector. That means that it will heat up, break down, and then detect either Chlorine, Fluorine, or Bromine chemicals that are leaking out of your unit. While this unit is significantly more expensive than our previous Good pick I can assure you that it’s many benefits and features outweigh the extra cost.

The Tek-Mate leak detector can detect all types of refrigerants. Yes, even HFOs. Again, I won’t list everything but some of the most popular refrigerants it can find are R-12, R-22, R-502, R-134a, R-404A, R-410A, and 1234YF. Along with the versatility of refrigerants it can detect it also comes with a extremely sensitive sensor that can even detect leaks as small as 0.15 ounces per year. (See below video.) That is a big step up from our previous nomination that had struggled with identifying those smaller leaks.

When a leak is found your sensor will go off emitting a beeping sound which most of you are used to but it will also give a visual cue as well causing lights to flash off and on giving you another indication that you have found the leak. This is just another way for you to be made aware as some of you, you know who you are, love to hit that mute button on your detectors and then twenty minutes later wonder why you aren’t detecting any leaks. At least with this visual cue you will have an idea where the leak is.

This product comes with a two year replaceable warranty. What that means is if your unit fails then Inficon will replace it. The thing to note here is that they will not warranty a unit that is being claimed against normal use. What is normal use? Well that could be sensors wearing out, filters wearing out, or you just didn’t take care of your unit. I can assure you that if you receive a bad product that they will replace it for you. For more information please check the owner’s manual.

The last big point that I’m going to make on this Tek-Mate unit is that it is proudly made in the United States of America. That’s a rare find nowadays. The unit I recommended before was of course made in China. Hell, it seems like everything is made there now.

To sum it up if you’re looking for a great quality sniffer, one that is USA made, and that provides you with the ability to detect a variety of refrigerants than this is your baby. However, if you’re still looking for that next bigger and better thing then I encourage you to read on my friends. Read on. One user stated, “Good meter but I believe there are better meters out there. They just cost a lot more. ”


Fieldpiece Heated Diode Refrigerant Leak Detector – SRL8

Fieldpiece Heated Diode Refrigerant Leak Detector - SRL8Check Price on Amazon

Alrighty folks, well we saved the best for last. Fieldpiece’s Heated Diode Refrigerant Leak Detector Model #: SRL8. This thing is the best of the best. If you don’t believe me ask other techs in the field. Fieldpiece is a renown name in the industry and they have earned it!

The SRL8 is a heated diode type of detector. It hunts for either Chlorine or Fluroine molecules. What that means is that this model can detect CFC, HFC, HCFC, and blended refrigerants. On top of all of that it can also detect the newer HFO refrigerants such as 1234YF or R-452A. The only downside here is that it cannot detect Hydrocarbon refrigerants such as Isobutane or Propane but these types of refrigerants are rare finds out in the field.

The sensitivity on this sensor is amazing. Remember how I was bragging about the Inficon’s ability to detect a leak at 0.15 ounces per year? Well the Fieldpiece SRL8 can detect leaks at less than 0.10 ounces per year. I told you we were at the best category! On top of the great sensor you also get a fifteen hour battery life. While that may not sound the longest battery life ever this model comes with a rechargeable ion battery. That means no more having to carry extra D cell batteries with you. No more hoping your battery didn’t die overnight. This ion battery comes with chargers for the garage and your vehicle. So you can charge the thing while driving from job to job.

The filter on this unit has a defense mechanism to protect your sensor from condensation or oil. If your unit senses contact with these elements the filter will swell and shut off the pull to the sensor protecting it from premature failure. In case you are unlucky and go through a couple a filters because of this the unit comes with ten replacement filters. Just in case.

The Fieldpiece SRL8 comes with a carrying case for easy put away and storage. While on the job you will notice that the detector comes with a tough rugged casing that stands up to years of abuse unlike the other guys. I swear some of these detectors will break if you look at the wrong, let alone if you accidentally drop them on the concrete.

The last thing I’m going to mention on this product is the one year warranty. This warranty only applies to failure of the unit and not wear and tear of your product over use. In other words, if you get the unit and the thing breaks in half on you after a month of use then you can get your money back. For more information on their warranty click here to go to Field piece’s official website. To be honest I expected a bit of a longer warranty for this price point but overall this is a great quality product that will make any tech happy they purchased.


In conclusion we’ve gone over the types of leak detection, what considerations that should be made before purchasing, and the top three Good, Better, Best types of leak detectors on the market today. The question you have to ask yourself is what kind of consumer are you? Will you be the lower price point guy or will you be the premium?

Oh, and if you are a business owner and are buying these for your techs then please… please at least buy them the better category!

Thanks for reading and I hope that I was able to help you in your buying decision.