Ac Repair Glossary

Plain-English explainers for the technical terms, rebates, regulations, and acronyms that show up when you shop for Ac Repair systems and services. Each entry links the underlying source, lists the numbers that matter, and points to related concepts.

AC Capacitor (Run / Start)
The small cylinder that gives your AC's motors the jolt to start and keep running — and the single most common AC repair.
AC Compressor
The pump at the heart of your air conditioner — and the one repair that often tips the decision toward replacing the whole system.
Contactor
The heavy-duty electrical switch that powers the outdoor unit on and off — a low-cost part that mimics big-ticket failures when it goes.
EPA Section 608 Certification
The federal certification a technician must hold to legally buy and handle the refrigerant inside your air conditioner.
Frozen Evaporator Coil
Ice on the indoor coil — a symptom, not a cause, that almost always points to low refrigerant or restricted airflow.
Hard-Start Kit
An add-on that boosts compressor starting torque — a legitimate fix for a struggling start, but sometimes sold as a band-aid for a dying compressor.
NATE Certification (North American Technician Excellence)
The largest independent skills exam for HVAC techs — a voluntary credential that signals real diagnostic competence beyond the legal minimum.
R-410A Phaseout & A2L Refrigerants
The 2025 switch from R-410A to lower-GWP A2L refrigerants — and why recharging an older AC keeps getting more expensive.
Refrigerant Leak Detection & Repair
Finding and sealing the leak before adding refrigerant — the law requires it, and topping off without it is the #1 AC repair scam.
Short Cycling
An AC that switches on and off in rapid bursts — comfort-killing, energy-wasting, and hard on the compressor.
Superheat & Subcooling
The two temperature readings a proper tech uses to charge your AC by the numbers — instead of guessing 'beer-can cold.'
Thermostatic Expansion Valve (TXV)
The metering valve that doses refrigerant into the coil — when it sticks, the AC under- or over-cools for no obvious reason.
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