ENVIRO-SAFE ProSeal XL4 AC Stop Leak for 1.5–5 Ton R410a/R22 Systems — Leak Sealer, Moisture Remover & UV Dye

ENVIRO-SAFE AC Stop Leak 3-in-1 ProSeal XL4 is a single, direct-inject formula that seals refrigerant leaks, removes system moisture, and adds UV dye for fast leak detection in 1.5–5 ton R410a and R22 systems.

This professional-grade, made-in-USA formula combines a sealant, a dehydrating agent, and fluorescent dye so you can treat leak-prone residential HVAC systems without pump-downs or lengthy service procedures. Designed for 1.5–5 ton central air conditioners, heat pumps, and mini-split systems, ProSeal XL4 works with common refrigerants including R410a, R22, R32, R454B, and R134a. The product injects on the low-side while the system runs, neutralizes moisture that accelerates corrosion, and leaves a visible UV tracer at the leak site.

How does this product stop leaks without taking the system offline?

ProSeal XL4 is formulated for direct injection into a live system via the low-side service port, eliminating the need to evacuate or pump-down most residential systems. A single trigger pull introduces the three components simultaneously, so one short service visit is often all that’s required.

• Direct-inject design: connect to low-side port and inject during normal operation.
• No vacuum pump required for standard residential systems.
• Single application: all three formulas dispense together in one pull.
• Allow the system to run about 45 minutes after injection for circulation.

Will it harm TXVs, expansion valves, or manufacturer's warranties?

ProSeal XL4 is engineered to be compatible with common system components and refrigerant oils to avoid damaging thermostatic expansion valves, TXVs, and compressor internals. The dehydrating agent converts water into a synthetic oil that does not leave corrosive residues, and the formula is made to avoid common warranty-voiding issues.

• Compatible with mineral and synthetic refrigerant oils.
• Safe for TXVs and expansion valve assemblies when used as directed.
• Formulated to leave no damaging solid residue inside the system.
• Not compatible with ammonia or CO2 refrigeration systems.

Which refrigerants, system sizes, and situations are best for ProSeal XL4?

ProSeal XL4 spans a broad range of common residential refrigerants and is intended for mid-sized systems from 1.5 to 5 tons. It is especially recommended for older units, systems that have been recharged multiple times, or installations in humid climates where moisture contamination is likely.

• Compatible refrigerants include R410a, R22, R32, R454B, and R134a.
• System capacity: 1.5 to 5 ton residential AC, heat pump, mini-split.
• Best for units older than 2010 or with visible corrosion signs.
• Ideal in high-humidity regions like Southeast, Gulf Coast, and Pacific Northwest.

How do I apply ProSeal XL4 and verify the leak location?

Application is quick: hook the canister to the low-side port, inject while the compressor is running, then let the system circulate. The included UV fluorescent dye highlights the sealed area so you can confidently locate and inspect the repair with a UV lamp.

• Connect to low-side service port; inject under normal system pressure.
• Inject using refrigerant pressure or high-side pressure if available.
• Run the system for ~45 minutes to disperse and treat moisture.
• Use a UV lamp to find dye-marked leak sites after treatment.

Who this is for: ENVIRO-SAFE ProSeal XL4 is made for HVAC technicians and knowledgeable homeowners who need a fast, all-in-one service option for residential systems 1.5–5 tons. Choose this 3-in-1 when moisture is suspected, when a system has needed multiple recharges, or when you need a quick field service that minimizes downtime. Not intended for industrial ammonia or CO2 systems; follow all service safety procedures and manufacturer guidance when using with warranty-covered equipment.