Best Refrigerant Leak Detector for HVAC Technicians

A refrigerant leak detector is an indispensable tool for all professional HVAC technicians. No matter where you work, this tool is one that you are going to be using on a regular basis. 

Ultimately, the cooling component of the HVAC system depends on the refrigerant chemical (usually freons) for the unit to work. However, if there happens to be a leak anywhere in the system, you are going to see a drop in pressure and an inability to provide cooled air.

With that said, here we will review some of the best refrigerant leak detector models available for specific applications. There are many pros and cons to each, which is always useful to know, as although we all want the best value, we also want to provide an excellent service that will make our job easier in the long run.  

Quick Picks: Refrigerant Leak Detector Reviews

Refrigerant Detector FEATURES
Signstek Refrigerant Leakage DetectorSingle color LED display
Coverage: 750 square foot
Check on Amazon
Inficon TEK-MateIncludes Sensor, 2 D Batteries, Filters, Carrying Case
Coverage: 650 square foot
Check on Amazon
Fieldpiece Refrigerant Leak DetectorCoverage: Outdoors
Triggers on all CFCs, HFCs, HCFCs and blends.
Check on Amazon

*All links above will take you to the latest prices on or you can read our best refrigerant leak detector reviews below.

For HVAC operators on a budget, this is a relatively good refrigerant leak detector.

It operates using the negative corona detection method, which is reliable and relatively accurate.  

This is ideal for someone just starting out in the HVAC industry and is probably the one that I would recommend. 

What type of refrigerants can it detect? The Signstek can easily detect the most common halogenated  refrigerant gases including R-12, R-22, R-502, R-410A, R-134a, and R-404A (and more but I won’t bore you).

However, it’s worth noting that this detector will not detect hydrocarbons including carbon dioxide. 

How long will it run for? This detector will provide fifty hours of continuous use. This may not seem like much, yet remember you are likely only going to have it running for a matter of minutes, until you locate the leak. When the sensor does expire, you don’t have to replace the entire unit either – just the sensor. 

Ultimately, the price is low and as a result this unit isn’t the best available. Compared to pricier alternatives this will kick out more false positives and you will probably have a difficult time locating small leaks. 

The bottom line is that this is a great unit for those on a budget. However, if you are looking for something a little more accurate that will save you a lot of time, then check out our other picks.  

The Inficon TEK-Mate refrigerant detector employs a heated diode method in order to detect gases. It is a pricier alternative to the latter unit, but well worth it for the additional benefits.

The heated diode detection method works by breaking up refrigerant gasses into chlorine, fluorine or bromine ions, which result in the production of an electric signal, allowing refrigerant to be easily detected. 

What gases can it detect? The Tek-Mate is able to detect refrigerant gases including R-12, R-22, R-502, R-134a and even HFO’s (along with many more). Perhaps the biggest advantage of this detector is just how sensitive it’s sensor is – it is able to detect leaks at 0.15 ounces per year. A huge advantage of cheaper alternatives, which is bound to save you time. 

When the device detects a leak a high pitched alarm will sound off and lights will also flash. The benefit of this is that you will have a visual cue, so if you accidentally switch the alarm off, you will still be made aware of the presence of gas. 

Another big benefit of this detector is the warranty offered by Inficon. They offer a solid 2 year replaceable warranty. So if the device breaks down, you know you can easily get a new one with no issues. 

To conclude, this is a good quality refrigerant leak detector with incredible accuracy, reliability and a solid warranty. Even better? It’s made in the USA. 

If you are looking for the best refrigerant leak detector model, then this one offered by Fieldpiece is certainly one of them and has a brilliant reputation in the HVAC field. 

The SRL8 relies on the heated diode method of detection. This works by breaking down refrigerant gases into their constituent components including flourine, bromine and chlorine. 

What gases can it detect? The SRL8 can detect all of the major refrigerant gases including CFC, HCFC and more modern gas mixtures.

However, bear in mind that is unable to detect hydrocarbons including ammonia and carbon dioxide. 

How sensitive is this device? The SRL8 has an incredible ability to detect  leaks at less than 0.10 ounces per year. In addition, it has a healthy 15 hour battery life, which is a good amount that will allow you to use it dozens of times between charges. 

Other great benefits that the SRL8 comes equipped with include an environmental defense system. Basically, if the device detects things like condensation it will shut down to protect itself. 

This device also comes with a very durable carry case that will guard your device for years to come. The amount of times I’ve seen people drop detectors and see them never turn on again is unbelievable, so this is certainly worth noting. 

Types of Leak Detection

Refrigerant leaks can result in a whole host of issues, with some common examples being residential customers experiencing their system being unable to cool them down when they most need it.

Businesses, on the other hand, could potentially lose money through their refrigerated stock becoming too warm or it may even result in their workforce becoming uncomfortable and less productive!

It’s absolutely vital for you to be able to detect and repair problems with an HVAC unit and leaks are especially important to look out for. As you probably know from your EPA certification, refrigerants are not environmentally friendly and can lead residents and businesses to be fined a lot of money.

You are probably aware that here are of course other methods for detecting leaks as an alternative to an electronic leak detector, ranging from the simple, albeit less accurate variety and these include:

  • Ultraviolet Dyes

The application of a UV dye to the HVAC system is one tried and true method. It’s certainly a clever idea to do this because then the leak can be identified using a UV light.

The major downside of this technique is it’s potential impact on the performance of the HVAC system. It can result in the system being altered due to the introduction of the dye as it can lead to changes in pressure so it does require an experienced and well-learned technician and a lot of time to perform this method of leak detection.

  • Soap and Water

The simplest, cheapest and probably the most inaccurate way of detecting a leak is applying soapy water to the suspected location.

The idea is that bubbles will form when you have applied the soapy water and it does indeed work to a degree, but as you can probably imagine it’s not very accurate and also does not really look very professional to clients, especially when working on a commercial property.

  • Electronic Leak Detectors

There is little doubt that electronic refrigerant leak detectors are the most accurate and therefore the most efficient and convenient way to detect leaks without you needing to take special measures. As would be the case if you employed the use of UV dyes or risk missing a leak all together with the soapy water method.

Since the devices range in quality on the marketplace, they can also range quite considerably in accuracy, precision, design and ultimately price so there are a few factors for you to take into consideration when shopping around to make sure you get your moneys worth.

Leak Detector Considerations

Just like buying anything else, prior to selecting a leak detector their are some key questions you should be able to answer before making a decision.

Is it built to last? How does it work? Is it accurate? What type of scenarios are you expecting it to work within? With that said, here are some of the most important considerations to make.

Types of Leak Detectors

  1. Corona Suppression Leak Detectors – This is by far one of the oldest forms of electronic leak detection. The method utilises two electrodes that measure the conductivity of refrigerant gases.

    The detector creates a baseline current, which can be disturbed by the presence of a refrigerant gas. In the event that a refrigerant is detected the device sounds an alarm.

  2.  Heated Diode Refrigerant Leak Detectors – These leak detectors operate by breaking apart the refrigerant gas molecules, resulting in the production of positively charged chlorine or fluorine ions that are attracted to a negatively charged plate within the device. In which case an alarm will be triggered.

  3. Ultrasonic Leak Detectors – Unlike the last two methods that rely on gas volume, ultrasonic (in many cases) are able to pinpoint the exact location of the gas leak. In simple terms, they do this by detecting the noise created from the pressure escaping from the system.

    This means they can be more useful in situations where  detecting gas volume alone would not be very helpful e.g. large leaks involving large volumes of gas.   

What Type of Refrigerant will it Detect?

Even though the EPA is beginning to phase out many gases. The reality is that on the job you are going to come across a wide variety of refrigerant gasses. Just over a decade ago you would have likely been ok with a leak detector that could just detect standard CFC, HCFCs, and HFC refrigerants.

However, this is no longer the case and refrigerant gas mixtures are now common place. Therefore, securing a versatile refrigerant leak detector capable of detecting a wide range of gases is essential. 

With that said, these are some of the most common refrigerant gases HVAC technicians are likely to encounter: 

  • CFC Chlorofluorocarbon R-12, R-502 (Already phased out)
  • HCFC (Hydrochlorofluorocarbon) R-22, R-401A, R-401B, R-402A, R-402B, R-408A, R-409A (Currently being phased out)
  • HFC Hydrofluorocarbon R-134a, R-404A, R-407C, R-410A, R-438A, R-507.

Leak Detection Capability

Unfortunately not all leak detectors are made equal and can vary not just with the type of gases they can detect, but also how efficiently and accurately they can detect leaking refrigerants. 

A detector that sounds the alarm at any volume of gas or due to fluctuations in air pressure is unlikely to be very helpful. Therefore, try to secure a detector that has a multi-stage alarm output. This means different levels of gas concentration should trigger a different alrm, which can be very useful when trying to locate a leak. 

Leak Detector Durability

The durability of your leak detector should not be disregarded. On the job all of your tools are likely to take a fall and your detector will be no different. Even more important with detectors are their inner components, which are sometimes only guaranteed to work for a certain amount of time. 

For example, some sensors are only advertised to work for 40 hours, therefore, after this period they be useless until you replace the parts. So this is definitely something to bear in mind. 

Protective cases should also not be taken for granted, especially when the device is in transit e.g. in the back of a vehicle. 

Final Words

To summarize, it’s best to stay away from the cheaper options, especially if you are going to be putting it to use on a regular basis. When it comes to value for your money, it isn’t about spending the least it’s about getting the highest quality product for less, ensuring the best accuracy, reliability and durability. 

That’s why you should check out our top picks, that’ll give you a good idea of what’s available for all budgets. 

About the Author

Dave Miller is a HVAC technician with over 10 years in the industry. Dave created HeatTalk with the ambition for it to become a resource for individuals looking for answers, whether they be a layman, student or a professional.

Leave a Comment