Mini-split not cooling with a flashing light: filters and coil cleaned

Last updated October 27, 2026Reviewed by Waseem Shahzad, Lead Technician

Babylon, NYMini-Split ServiceTechnician: WaseemMay 2026

A three-year-old mini-split was not cooling and flashing its operation light. Dirty filters and a dirty outdoor coil were cleaned; refrigerant was good.

Indoor mini-split filters cleaned on a no-cooling call, Babylon NY

Mini-split blower wheel inspected, Babylon NY

Indoor blower and coil area of a ductless unit, Babylon NY

Line set at the outdoor mini-split unit, Babylon NY

What the homeowner reported

The homeowner reported that a three-year-old mini-split was not cooling and its operation light was flashing.

What we found

The indoor unit filters were dirty, and the outdoor condenser coil needed cleaning. The refrigerant level was good.

What we did

Waseem cleaned all of the indoor filters and cleaned the outdoor condenser coil.

The result

With the filters and coil cleaned, the refrigerant level checked good. The record notes that if the problem returns, the next step is new flare connections, a pump-down and a nitrogen pressure test.

Job details are from our May 2026 service record for this Babylon home. Customer details are left out.

General information, not details from this job

About flashing mini-split lights

A flashing operation light is the unit telling you it has stopped for a reason, and the blink pattern points to the fault. Restricted airflow from clogged filters or a dirty outdoor coil is one of the simplest causes, which is why cleaning comes first. If a fault keeps coming back with clean coils and a good charge, the flare connections are the next suspect, and the proper fix is to remake them, pressure test with nitrogen and evacuate the system rather than add refrigerant.