A sealed system should never need refrigerant. If it does, there is a leak, and this is the single most useful thing to understand before agreeing to a recharge. The signs are cooling that weakens year on year, ice forming on the line set or evaporator coil, a hissing or bubbling sound near the indoor unit, and longer run times for less result. Common leak points are the evaporator coil itself, brazed joints at the line set, Schrader valve cores, and corrosion at the outdoor coil.
A recharge without finding the leak is a repeat visit rather than a fix, and older refrigerant blends are being phased down. Running low charge also makes the compressor run hot, and a failed compressor is one of the biggest repairs a system can need. Ask for the leak to be located before agreeing to add refrigerant. Pro HVAC connects homeowners in Cleveland Heights, OH with HVAC professionals who can locate and repair the leak. Call (321) 463-9811.