ENVIRO-SAFE AC Stop Leak with UV Dye — ProSeal XL4 1.5–5 Ton Direct-Inject Cartridge, Seals Pinhole Leaks

ENVIRO-SAFE ProSeal XL4 is a direct-inject refrigerant stop-leak with built-in UV dye that seals pinhole leaks and instantly marks leak paths for R410a, R22, R32, R134a and other residential/light-commercial refrigerants.

This cartridge combines the proven ProSeal XL4 sealing formula with a factory-grade ultraviolet tracer so you can both repair and locate leaks in one service visit. Designed for use in central air conditioners, heat pumps and mini-splits from about 1.5 to 5 tons, the product works with common refrigerants and all lubricant types. It installs quickly on the service port and circulates while the system runs, simplifying diagnostics and reducing downtime without requiring pump-down or extra dye injection steps.

How does it stop a leak without removing refrigerant?

ProSeal XL4 is engineered to be added directly to a charged system via the low-side service port or using available system pressures. The formula contains micro-sealants that travel with the refrigerant and lodge at pinhole-size faults, forming a flexible, long-lasting plug while the UV dye tags the flow path.

• Direct-inject in 1 trigger pull—no separate dye injection needed
• Works while the system runs; typical 45-minute circulation time
• Compatible with TXVs, capillaries, gauges and recovery equipment
• Seals pinholes, hairline and many small leaks without pump-down

Which refrigerants and systems are compatible?

ProSeal XL4 is formulated for residential and light-commercial HVAC systems using common HFC and hydrofluoroolefin blends. It’s compatible with R410a, R22, R32, R134a, R454B and many others; it is not intended for ammonia or CO2 industrial refrigeration.

• Works across oils and lubricant types used in HVAC systems
• Suitable for central ACs, heat pumps and mini-splits (1.5–5 ton range)
• Not recommended for ammonia (NH3) or CO2 systems
• Proven in millions of field installations since 2014

Will the UV dye help me find the leak site reliably?

The integrated UV dye circulates with the refrigerant and highlights areas where refrigerant escapes, so a fluorescent inspection will reveal the exact leak location. If the sealant successfully plugs the leak, the dye still shows the original leak path so further servicing is targeted and efficient.

• UV dye is the same grade used by OEMs—bright and dependable under UV light
• Marks oil and refrigerant trails on fittings, coils, hoses and joints
• Helping technicians pinpoint service points reduces repair time
• Useful whether a seal holds or additional mechanical repair is required

Is it safe for system components and warranties?

ProSeal XL4 is formulated to be chemically compatible with common HVAC materials and components; Enviro-Safe reports no warranty-voiding incidents across millions of applications. The cartridge and dye meet professional service standards and are safe to use with gauges, TXVs, capillary tubes and recovery tools when applied according to directions.

• Non-corrosive, compatible with metering devices and valve types
• Computer-blended in the USA to consistent quality standards
• Used by technicians to avoid unnecessary component replacement
• Follow manufacturer instructions; not for industrial refrigerants like CO2

Who is this for: ProSeal XL4 is aimed at HVAC technicians, service contractors and informed homeowners who need a fast, one-step solution to stop small refrigerant leaks and accurately identify leak locations. It’s a practical choice for routine service calls on residential and light-commercial systems where downtime, diagnostic time and refrigerant handling are concerns. For large industrial installations using ammonia or CO2, or for major mechanical failures, conventional repair methods remain necessary.