AC Short Cycling
Quick Answer
Short cycling occurs when your AC turns on and off every few minutes instead of running complete 15-20 minute cycles. Common causes include dirty filters, refrigerant leaks, thermostat problems, or an oversized AC unit. This wastes energy and damages your system.
Safe Checks You Can Do
- 1Replace the air filter - A clogged filter is the #1 cause of short cycling. Check and replace if dirty.
- 2Check thermostat location - If near a window, vent, or heat source, it may get false readings.
- 3Inspect the evaporator coil - Look for ice or frost on the indoor coil through the access panel.
- 4Clear the outdoor unit - Remove leaves, grass, and debris. Ensure proper airflow around the condenser.
Likely Causes
- Dirty or clogged air filter
Restricts airflow, causing the system to overheat and trigger safety shutoff.
- Low refrigerant
A leak causes pressure drops that trigger the high-pressure safety switch.
- Oversized AC unit
Cools too quickly and shuts off before completing a proper cycle. Common in incorrectly sized installations.
- Faulty thermostat
Incorrect readings or poor placement causes the system to cycle erratically.
- Frozen evaporator coil
Ice buildup blocks airflow and causes the system to shut down repeatedly.
When to Call a Pro
- Short cycling continues after replacing the filter
- You notice ice on the refrigerant lines or coils
- The AC was recently installed and seems too powerful
- You hear clicking sounds when the system shuts off
- The outdoor unit trips its circuit breaker