Most manufacturer warranties cover only the replacement coil part itself—not the costs you'll actually pay. What warranty typically does NOT cover: labor to diagnose the problem ($150-300), labor to remove and install the new coil ($400-1,200), refrigerant recovery and recharge ($200-600), emergency/after-hours service premiums ($100-300), modifications needed for replacement coil fit, and your time without AC waiting for parts and scheduling. Total out-of-pocket even WITH warranty coverage: $850-$2,400. And during peak summer season, you could wait 1-3 weeks for parts and scheduling while living in an uncomfortable—or even dangerous—environment. CoilShield prevents these failures from happening in the first place.