Nu-Calgon 4050-11 EasySeal Direct Inject-UV Dye Refrigerant Leak Sealant, One Size Treats Systems 2 to 7.5 Tons

I’ve used this product over a dozen times as a certified HVAC technician. Only once has it not worked and it took several months to lose the refrigerant again. If you’re trying to stop a MINOR leak and you have lost half your refrigerant (example 50 psi or less for R22 and 70 psi or less for R410A), don’t expect this product to work. Use common sense!

Great, ease to add into the system and worked really quick to seal small hole in the coil. Excellent value and saved time and money of a coil replacement.

We are in South Florida and I do our HVAC work since I did it for a living before retiring. We HAD a pinhole leak in the evap on our Lennox 2.5T. I was adding .5 lbs of 410a monthly. I keep a spare Lennox evap brand new in the garage but I was in cancer treatment and did not want to replace it. It's still there. I added one shot of Easy Seal. Now February 2026. In four months it'll be three years. No leaks! My leak detector does not even pick up the leak anymore. This product is not just a "seal". It plates over the leak. Nu-Calgon makes other HVAC products as well, for cleaning, etc... I tend to stick to their excellent products. Under the labeled conditions it does what it says! Great product! Little pinhole leak in the evap. I used this in June 2023. It is now February 2025. We live near Tampa Bay in Balm Florida. We have some summer days of 105° with a Reelfeel of 125°. I was losing .5 lbs per month up until June 2023. Since adding this product nineteenonths ago, no leaks. 2010 Rheem.14SEER 3.5T.

I was very skeptical using this product and I was also concerned about stopping up the free on system and totally ruining it. I didn't have a large leak I don't have a clue where it was it was very slow. But honestly I'm very happy I used this it worked very well it stopped my free on loss totally since I put this product in the system I have not had to add any more freon to the system and it works very well

Excellent!!!! Please keep these items on my Amazon orders just in case I need to reorder again. Thank you Amazon youre THE BEST.

Snake oil so did not work. I was very hopeful but totally disappointed, it did bit stop any leaks. I wasted the price for this item and the additional refrigerant cost. I did not get any refund.

Update: 9 months later and still no leak I have waited 2 months after using this product to write this review. I have a 22 year old R22 unit that was losing about a half a pound of refrigerant a month. So a slow to moderate leak. This product was my last attempt to save this system. I have HVAC experience and found the product easy to use. After 2 months I have not had to add refrigerant and leak seems to be sealed. This system is on a rental unit and if I can get a few more years out of it I will be happy. I recommend this product as a last ditch effort to extend the life of a failing system.

My evaporator coil was frozen over, AC pumping out hot air, obviously had a leak. Was low 18 oz of Freon. AC tech topped off the Freon and had him add this during the process. 4 weeks later still no leaks and ice cold air. 🤓 It treats up to 7.5 ton unit, my unit is only 2 ton, who cares, I was desperate and last resort. Let it rip! Hopefully I can get a few more years out of this 10 year old unit before upgrading to a 3.5 ton.