Product Review: Signstek HLD-100 Refrigerant Leak Detector

Signstek HLD-100 Refrigerant Leak Detector












Hello ladies and gentlemen and welcome! Today on RefrigerantHQ we will be taking an in-depth look and review at Signstek’s Portable Refrigerant Leak Detector. Over the past few months I have gone through and have done numerous reviews on all different types of leak detectors. Some of these were the best of the best, some were mediocre, and some weren’t so good. I feel that by now that I am getting to know these things like the back of my hand. But hey that’s enough about me let’s take a look at Signstek’s product.Signstek HLD-100 Refrigerant Leak Detector

For those of my readers you know by now that in this section I usually do a short blurb about the manufacturing company of the product. The goal here is to familiarize ourselves with the company and to see what they are known for. In my opinion it doesn’t make sense to buy if you don’t even know about the company.

Well folks I searched and searched online trying to find Signstek’s official website so that I could research them. Guess what? There isn’t one. Yup, there is no website that I could find. Instead I read through other sources and came to the conclusion that this product is Chinese made and imported in mass here to the United States. I even found the HLD-100 on

For those of you who don’t know Alibaba is a Chinese website designed for exporting their product. In this case the HLD-100 detector can be bought in a three-hundred piece order out of ShangHai. Feeling good about this product yet? Neither am I.


When I was doing my research on this Signstek HLD-100 detector I couldn’t even find what type of detector this was. At first I thought it was a corona suppression model but then I read that this unit was detecting the Ions of Fluorine, Chlorine, and Bromine. Reading that triggered me into believing that this was a heated diode model, but I am not one-hundred percent and to be frank there just isn’t enough information out there to know for sure.  For now, I will treat this unit as if it is a heated diode. A diode detector heats up the environment around it and then breaks the molecules apart. When the molecules are broken and there is refrigerant in the area either a positively charged Chlorine or Fluorine ion will appear. The heated diode detector then senses these ions and reports back to you that there is a leak. So, in short I believe this is a heated diode refrigerant leak detector like many others that are on the market today.

According to Amazon and other retailers this product can detect all of the common classifications of refrigerants such as CFCs, HCFCs, and HFCs. These classifications cover your most popular refrigerants such as R-12, R-22, R-134a, R-404A, and R-410A. Again, according to Amazon and other third party sites the sensitivity levels 0f 0.10 ounces per year. I am highly skeptical of this but I will save these comments for further on down in the review.Upon starting up the unit it will require about five to ten seconds of warm up time so it can zero itself out. When scanning you will notice audio and visual alerts when a leak is found. The sensor on this unit will last for fifty hours.

The probe extends to fourteen inches which is pretty standard for cheaper detectors. Most other detectors will range between fourteen to fifteen inches. Some of the premium models go up to seventeen inches and the best detector on the market today goes up to fifty-four inches. (The H-10 Pro.) The last point I will make on this is the unit takes regular batteries instead of a rechargeable. I didn’t expect this to take rechargeable batteries but it is worth bringing up nonetheless.


  • Well first of all and most of all the best benefit of this unit is the price. This one of the cheapest, if not the cheapest, refrigerant leak detectors on the market today. As I write this the price for this unit is under fifty dollars. (Prices are subject to change at any time.) That is one hell of a bargain but just keep in mind folks that you get what you pay for. This is not a perfect unit by any means.
  • Through my research one of the bright spots that I found on the Signstek HLD-100 was that it was able to find the larger leaks relatively easily. It did struggle with smaller leaks but that is a different story.


There is a whole list of Cons on this product and I won’t even list them all as there are just too many. Here is a brief synopsis:

  • As I just said above this unit struggled to find smaller leaks. In some cases not finding them at all while a better detector could easily trace the leak down. After writing this review I am skeptical of Signstek’s claims that this unit can detect leaks as small as 0.10 ounces per year.
  • The sensor life on this detector is only rated for fifty hours of use. That’s it. Then you have to replace the sensor. You do get one extra sensing tip when you purchase but after that you may very well be out of luck.
  • There are many reports of false positive readings on this HLD-100 detector. I feel that this has a direct correlation to quality.
  • Users have stated that the detector will ‘eat’ batteries. What this means is you put in fresh new batteries and come back the next day to find that the batteries are dead and your detector will not turn on.
  • The last Con on this product, and a big one at that, is that there is no written warranty policy that I could find. Each time I found anything regarding warranty it always stated to directly contact the manufacturer, but I can’t even find the manufacturer’s website. So, who actually even knows what this policy is. To me it seems like a gamble.


Overall folks, I would rate this product as a do-not-buy. Sure you get some savings when comparing to other detectors on the market today but honestly folks it just isn’t worth it. You’re going to be frustrated and may end up buying another one of these after a few months or you may then end up upgrading to a nicer unit. If you are considering this product here is what I would recommend:

  • If you are a beginner, novice, or middle of the road guy then view our review on the INFICON Tek-Mate. Yes, this unit is about one-hundred dollars more expensive but I can assure you that you are getting a quality product that will last.
  • Now, if you are a premium guy looking to get the best of the best then I would recommend looking at our Prowler VS H-10 Pro comparison chart and see which one you want to purchase. Just keep in mind that these are high dollar items and will cost a pretty penny.

Lastly, folks if you still have your heart set on the Signstek HLD-100 then by all means go ahead and purchase by clicking this link. Just be forewarned that I did try to steer you away from this unit.

Important Links

What’s In The Box?

  • Detector, of course.
  • Extra sensing tip
  • Alkaline Batteries
  • Full Instruction Manual