5 Signs Your A/C Has a Refrigerant Leak (and Why It Matters)

Refrigerant (still commonly called 'freon') doesn't get used up like fuel. If you're low, it leaked. Topping off without finding the leak is throwing money outside — and on R-410A or the newer R-454B systems, that money adds up quickly.

Sign 1 — Long run times, weak cooling

The unit runs nonstop but the house never reaches setpoint. Low charge means low capacity.

Sign 2 — Ice on the copper line set

Visible frost on the larger insulated copper line outside is a classic low-charge symptom in a humid climate.

Sign 3 — Hissing or bubbling near the unit

Refrigerant under pressure leaving a pinhole makes a faint hiss. Don't ignore it.

Sign 4 — Power bill jumps with no usage change

Same thermostat, same routine, $40–$80 higher bill. A struggling A/C is the most common culprit in central Florida.

Sign 5 — Oily residue on the copper or coil

Refrigerant carries compressor oil. A wet, oily spot on a line set or evaporator coil is where the leak is.

Why it matters

A starved compressor overheats and fails — and a compressor failure on a 12-year-old system usually pushes the conversation toward a full change-out. Catching a leak at sign 1 or 2 keeps you in repair territory.