Mini Split Turns On Then Off Repeatedly (Short Cycling)

Modified on Wed, 2 Apr at 1:22 PM

Overview

If your mini split air conditioner turns on briefly, then shuts off again — and repeats this cycle — it’s likely experiencing what’s called short cycling. This issue can lead to poor performance, increased energy usage, and long-term damage if not addressed.

Common Causes of Short Cycling

1. Dirty or Clogged Air Filter

A blocked air filter can restrict airflow, causing the system to overheat or shut off prematurely.

What to check: Remove and inspect the indoor unit’s air filter.
What to do: Clean or replace the filter if it looks dusty or dirty. Filters should be cleaned every 30–60 days.

2. Oversized Unit

If the mini split is too large for the room it's cooling or heating, it may reach the set temperature too quickly and shut off repeatedly.

What to check: Has the unit always short cycled since installation? Was it professionally sized?
What to do: Consult with an HVAC technician to evaluate system sizing and possible solutions like adjusting settings or adding a compatible zone.

3. Thermostat or Remote Sensor Issues

Incorrect sensor placement or a faulty sensor can send inaccurate temperature readings to the system.

What to check: Make sure the sensor isn’t near heat sources, vents, or windows.
What to do: Try relocating the sensor or remote, or have a technician inspect the internal thermistor.

4. Low Refrigerant Levels

Low refrigerant due to a leak can cause the compressor to shut down quickly to prevent damage.

What to check: Look for signs like ice on the refrigerant lines or weak cooling performance.
What to do: A licensed HVAC technician will need to check and recharge the refrigerant.

5. Electrical or Control Board Issues

Problems with the control board, relay, or capacitor can cause erratic power cycling.

What to do: If all else fails, a professional inspection is needed to check internal components.

What You Can Try First

Clean or replace the air filters.
Check the thermostat settings and ensure the room sensor is placed properly.
Power cycle the system by turning it off at the breaker for 5 minutes, then turning it back on.

Need More Help?

If the issue persists after trying the above, please submit a support ticket or contact our technical support team. Short cycling can lead to long-term damage if not resolved quickly.