Why isn't my mini-split's outdoor unit running?
First rule out the normal delay: many units hold the compressor off for a few minutes after starting or after a power cut. Daikin says to wait 3 to 4 minutes for the compressor to start, and Fujitsu notes a 3-minute protection delay whenever power is interrupted. If it still doesn't start, the likely causes are a tripped breaker or disconnect, a failed fan motor or capacitor, a control-board fault, or a communication problem between the indoor and outdoor units — MRCOOL, for example, lists EL-01/E1 as an indoor/outdoor communication malfunction.
What do different noises mean?
- Humming or buzzing with no fan movement: often a failing capacitor or motor. Switch it off — running it can overheat the motor.
- Rattling or clicking: loose panels, debris in the fan, or a worn fan motor or mounting.
- Grinding or screeching: motor bearings or the compressor — have it looked at soon.
- Hissing or gurgling at the indoor unit: can be normal refrigerant flow, but persistent hissing with poor cooling can mean a refrigerant leak.
What if I smell something?
A burning or electrical smell is a stop-now sign. Mitsubishi Electric's manual says that in an abnormal condition such as a burning smell, stop the air conditioner and turn the breaker off, then call for service. A musty smell is different — that's usually mold in the indoor head; see cleaning & maintenance.
After a hurricane or flood
Florida's hurricane season runs June 1 to November 30. If the outdoor unit was underwater, hit by debris, or knocked off its stand, don't switch it on — have it inspected first. Florida's building code addresses how outdoor mechanical equipment is fastened to stands, slabs or walls for wind resistance, so a unit that's shifted or loose should be re-secured properly. Our mini-split repair referral line for Florida can connect you with a technician after a storm.
What will the technician check?
Power and disconnect, the capacitor and contactor (where fitted), fan motor, control board and fuses, the communication wiring between units, and compressor operation — plus any stored error codes. They should tell you whether it's a simple part or a major component before going further.