Top 10 Best ac sealant in 2026

Last Updated - 6/29/2026

🏆Best Choice

Refrigeration Technologies

Refrigeration Technologies RT201B Nylog Gasket/Thread Sealant, 30 ml (1 Pack)

9.8

ChoiceComparer.com Score

9.8

/ 10

Outstanding

Main highlights

•Will not Contaminate Systems
•Seals Flares and Threaded Connections
•Lubricates O-Rings and Gaskets
•Approved by OEM Manufacturers

View offer on:

$13.95

Check Price

Leak Saver

Leak Saver Direct Inject AC Leak Sealer | AC Stop Leak for Most HVAC Systems Up to 5 Tons | Works with All Systems & AC Refrigerants | Made in The USA

9.7

ChoiceComparer.com Score

9.7

/ 10

Outstanding

Main highlights

•STOP LEAKS PERMANENTLY - The Leak Saver can permanently seal small refrigerant leaks where the complete refrigerant charge is not lost within 7 days. When a leak occurs, the Leak Saver reacts with the air and moisture at the leak site to permanently seal the leak. When used for preventative maintenance, the active ingredient circulates safely in the system to seal future leaks
•WORKS WITH ALL SYSTEMS INCLUDING CARS - Our product is compatible with all systems, refrigerants (except ammonia), car refrigerants, and oils. It is great for central air conditioners, automotive air conditioners, refrigerators, ductless mini-splits, heat pumps, geothermal heat pumps, commercial refrigeration systems, micro channel coils and more. It also works with all refrigerants including R410A Freon, R22 and replacements, R134A , r1234yf, R404A, R290, R600a, and more
•STRAIGHTFORWARD INSTALLATION - No more fussing with messy syringes, hoses, or pressurized cans. The Leak Saver HVAC sealant injects directly and easily into the system with a basic manifold gauge set or even easier with our Leak Shot Injection Kits. NOTE: for automotive systems, you will still need the standard 134A to 1/4” charging adapter. Mini-splits may require a 5/16” to 1/4” charging adapter. You can see our straightforward installation videos below
•SAFE FOR ALL TOOLS AND PARTS - Our HVAC leak sealer is safe for all manifold gauges, hoses, expansion valves (TXVs, TEVs, capillary tubes, etc), Schrader valves, and anything needed to service your system. Adapter required for mini splits (5/16" to 1/4") and automotive systems ( 134A to 1/4")
•THE MOST TRUSTED - The numbers don’t lie! With more than 4,000,000 units sold of our air conditioner leak sealer formula since 2015, we are the most trusted leak sealant among HVAC professionals. Proudly made in the USA. We stand 100% behind the quality of our products. If for any reason you are not satisfied with your order, reach out to us and we will make it right

View offer on:

$35.95

$38.95

-8%

Check Price

ERRECOM

Extreme Ultra A/C Leak Stop Direct Easy Inject Solution for HVAC&R Systems up to 6 Tons with 1/4 SAE Charging Port, for all Refrigerants and Oils | Reusable, Refillable, US Patented - 0.2 fl oz (6 mL)

9.5

ChoiceComparer.com Score

9.5

/ 10

Outstanding

Main highlights

•SEALS REFRIGERANT LEAKS: successfully stops small refrigerant leaks in A/C and refrigeration systems. Perform a 5-minute vacuum test to ensure the leak can be repaired with Extreme Ultra
•THE SAFEST CHOICE – POLYMER-FREE FORMULA: does not react with moisture or oxygen, ensuring maximum system protection and preventing blockages or damage to HVAC/R components, including expansion valves (TXVs, TEVs, capillary tubes) and Schrader valves
•REUSABLE & REFILLABLE SYSTEM US PATENTED (US 11002470): it can be reused with every new application. Just purchase the Extreme Ultra cartridge alone next time and save money on your refill!
•OEM-APPROVED FORMULA: developed by Errecom’s in-house chemical laboratory, trusted by HVAC technicians and OEMs since 2001 in over 130 countries
•Ideal for PREVENTATIVE MAINTENANCE: AVOIDS LEAKS before they develop.
•100% Made in Italy formulation and production

View offer on:

$34.00

Check Price

BlueDevil Products

Red Angel 00222 A/C Stop Leak & Conditioner - 4.5 Ounce

9.4

ChoiceComparer.com Score

9.4

/ 10

Excellent

Main highlights

•Guaranteed Permanent Seal
•Will Not Clog or Damage the A/C System or Recovery Unit
•GUARANTEED PERMANENT SEAL
•Now with UV Dye for leak detection

View offer on:

$31.04

$35.95

-14%

Check Price

A/C Pro

A/C Pro Car Air Conditioner, Certified A/C Pro Refrigerant Leak Stop Kit for R134A Car Air Conditioners, 3 Oz Each

9.2

ChoiceComparer.com Score

9.2

/ 10

Excellent

Main highlights

•Contains approximately 1.5oz of refrigerant and 1.5oz of additives
•Repairs Metal Leaks in evaporators, condensers, compressors, accumulators and receiver dryers
•Seals Rubber Leaks in O-rings, gaskets, and hoses
•With red dye for detecting leaks too large to repair
•Reusable dispensing hose designed for compliance and to work only with R-134a cans with self-sealing valve can tops

View offer on:

$27.99

$32.97

-15%

Check Price

BlueDevil Products

BlueDevil Products Red Angel 49496 A/C Stop Leak - 2 Ounce

9.1

ChoiceComparer.com Score

9.1

/ 10

Excellent

Main highlights

•Remarkable ability to repair and seal leaks in condensers, evaporators, connection hoses, gaskets, and O-rings
•Contains no solid or particulate matter that will clog the A/C system, or harm a recovery unit
•Forms a chemical weld sealing leaks in both R-12 or R-134a systems
•Safe to use and best of all — it’s a permanent seal
•Guaranteed

View offer on:

$21.99

Check Price

Rectorseal

RectorSeal AC Leak Freeze Pro Nano 45316 HVAC Leak Sealant, Contains New Leak Seeking Nano Particles That Create A Stronger Dual Sealant; Easy Application, HVAC, 1.5 oz

8.9

ChoiceComparer.com Score

8.9

/ 10

Great

Main highlights

•APPLICATION: AC Leak Freeze PRO refrigerant leak sealant with new leak seeking nano particles creates a stronger dual sealant; nano particles are non-polymer and non-reactive technology that fills cracks and imperfections in hvac coils
•EASY TO APPLY: Standard 1/4" ac leak freeze adapter; ready to use and safe for hvac systems; oem approved and professional install is recommended; restores AC performance quickly
•STOP LEAKS PERMANENTLY: AC Leak Freeze will stop leaks of refrigerant gas in hvacr air conditioning and refrigeration systems in homes and commercial buildings; ac leak freeze revitalizes ac and refrigeration systems by permanently sealing small, hard-to-find micro leaks
•SPECIFICATIONS: 1.5 oz pro nano; triple action sealant; polymer free, non-flammable and non-toxic; oem approved and safe for hvac systems; low loss safety fitting
•FOR THE TRADESMAN: RectorSeal is recognized as a leading provider of quality solutions for the professional trades serving heating, ventilation, and air conditioning (HVAC/R), plumbing, electrical, and construction markets

View offer on:

$51.20

Check Price

RED TEK

RED TEK ProSeal12 A/C Seal Treatment (4 oz. can)

8.8

ChoiceComparer.com Score

8.8

/ 10

Great

Main highlights

•Operation: Easy to use. Installs in minutes. Remains in system as a liquid lubricant ready to seal any future leaks.
•Lower Cost: Less expensive than replacing leaking evaporators, condensers, compressors, and metal lines.
•Compatibility: Compatible with most common refrigeration materials and lubricants including R134a, R12, metal components, mineral and synthetic(Ester and PAG) lubricants, seals, gaskets, hoses, compressors, and o-rings.
•Environment: Helps environment by reducing refrigerant emissions.
•Safety: Safe and easy to use. Less toxic than other seal treatments that contain poisonous methanol. No long term health risks have been attributed to RED TEK ProSeal.
•IMPORTANT INFORMATION: This product cannot be returned because it uses flammable liquids and gases, is classified as a hazardous material, or meets other criteria. This is a non refundable, non returnable product.

View offer on:

$25.95

Check Price

Rectorseal

RectorSeal AC Leak Freeze Pro Nano with UV 45318 Refrigerant Leak Sealant, Quick and Easy, HVAC, 1.5 oz.

8.6

ChoiceComparer.com Score

8.6

/ 10

Good

Main highlights

•APPLICATION: AC Leak Freeze PRO refrigerant leak sealant with new leak seeking nano particles creates a stronger dual sealant; nano particles are non-polymer and non-reactive technology that fills cracks and imperfections in hvac coils
•EASY TO APPLY: Standard 1/4" AC leak freeze adapter; ready to use and safe for HVAC systems; OEM approved and professional install is recommended
•STOP LEAKS PERMANENTLY: AC leak freeze will stop leaks of refrigerant gas in HVACR air conditioning and refrigeration systems in homes and commercial buildings; AC leak freeze revitalizes AC and refrigeration systems by permanently sealing small, hard-to-find micro leaks
•SPECIFICATIONS: 1.5 oz leak freeze pro nano with UV; UV formula adds the ability for a UV light source to detect larger leaks; polymer free, non-flammable and non-toxic; OEM approved and safe for HVAC systems
•FOR THE TRADESMAN: RectorSeal is recognized as a leading provider of quality solutions for the professional trades serving heating, ventilation, and air conditioning (HVAC/R), plumbing, electrical, and construction markets

View offer on:

$59.40

Check Price

Rectorseal

Rectorseal 45317 Leak Sealer, 1.5 oz, Green

8.5

ChoiceComparer.com Score

8.5

/ 10

Good

Main highlights

•APPLICATION: AC Leak Freeze PRO refrigerant leak sealant with new leak seeking nano particles creates a stronger dual sealant; nano particles are non-polymer and non-reactive technology that fills cracks and imperfections in hvac coils
•EASY TO APPLY: Standard 1/4" AC leak freeze adapter; ready to use and safe for HVAC systems; OEM approved and professional install is recommended
•STOP LEAKS PERMANENTLY: AC leak freeze will stop leaks of refrigerant gas in HVACR air conditioning and refrigeration systems in homes and commercial buildings; AC leak freeze revitalizes AC and refrigeration systems by permanently sealing small, hard-to-find micro leaks
•SPECIFICATIONS: 1.5 oz Pro Nano with magic frost; triple action sealant; polymer free, non-flammable and non-toxic; OEM approved and safe for HVAC systems
•FOR THE TRADESMAN: RectorSeal is recognized as a leading provider of quality solutions for the professional trades serving heating, ventilation, and air conditioning (HVAC/R), plumbing, electrical, and construction markets

View offer on:

$62.37

Check Price

📊

📈 How we rank

With our cutting-edge technology, we examine thousands of products and retailers, assessing reviews, ratings, trends, and sales rankings to identify what matters most to users like you.

Our team evaluates this data alongside genuine user feedback, merging AI analysis with human insights to provide you with real-time, highly-rated recommendations that empower your decision-making with clarity and confidence.