This page walks through what each pattern looks like from your living room so you can tell us what you see — the more you can describe, the faster the fix.
What this covers
- Airflow check: filter, blower, and return paths
- Frozen-coil thaw-and-diagnose protocol
- Refrigerant charge and leak testing
- Duct leakage and attic-air intrusion check
- Outdoor unit electrical diagnosis
- Thermostat calibration check
Signs you need this
- Weak airflow from the registers
- Vents blowing cool-but-not-cold air
- One room hot while the rest of the house is fine
- Outdoor fan not spinning, or the whole unit silent
- Hissing or bubbling sounds near the refrigerant lines
Shoals notes
In river-adjacent neighborhoods — Sheffield, Tuscumbia, and the Florence waterfront especially — high humidity loads the coil harder than the temperature alone suggests. Systems here fail 'not cooling' before they fail 'not running.'
Questions we get
Should I turn the system off if I see ice on it?
Yes — switch it to OFF at the thermostat and run the fan only if you can. Letting it melt while we are on the way prevents a sludge bath at the indoor unit. Do not chip at the ice.
Will a dirty filter really cause this?
It is the single most common cause we find. A choked filter starves the evaporator coil until it freezes over and stops absorbing heat. If the ice is back within days of a filter change, the underlying cause is usually airflow or charge — that is the diagnostic step.