Short answer
Count the blinks and write the pattern down: it is an error code. Set the remote to "Cool" (the snowflake) a few degrees lower and check its batteries. Turn the power off, lift the front panel, rinse the mesh filters and let them dry. Then reset it: breaker off for about 5 minutes, then back on. If it still blinks or blows warm, call a technician with the code.
Safety first
Turn the unit off at the breaker or the outdoor disconnect before you lift the panel or touch the filters. Use a sturdy step ladder, since the indoor unit is mounted high. Never spray water into the unit or open the outdoor unit.
How to check a mini split that is not cooling
1Warm air and a blinking light
Count the blinks and the pause, or read the code on the display. Write it down before you reset anything.
Read all the steps
- Warm air and a blinking light. Count the blinks and the pause, or read the code on the display. Write it down before you reset anything.
- Remote on Cool, a few degrees lower. Look for the snowflake, not the sun, the drop or the fan. Set it a few degrees below the room. Weak remote? Replace the batteries.
- Power off and rinse the filters. Turn it off at the breaker. Lift the front panel, slide out the mesh filters, rinse them with lukewarm water and let them dry.
- Filters back, wait 5 minutes, power on. Put the dry filters back. Leave the breaker off about 5 minutes, then turn it back on and start the unit from the remote.
- Cold air and a steady light. Give it 15 minutes. If the light blinks again or the air stays warm, call a technician and tell them the code.
- Still not fixed? Call an HVAC contractor Especially if: the light blinks again after a reset.
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What the blinking means
Most mini splits flash a light or show a short code when a sensor, the outdoor unit or the connection between them has a problem. Some also blink to remind you to clean the filters. Codes differ by brand, so look yours up in the manual. A reset clears a passing glitch; a code that comes back needs a technician.
Also check outside
- Clear leaves, grass and plants around the outdoor unit, with the power off.
- Look for ice on the outdoor unit or the copper lines while it is cooling.
- Make sure the outdoor fan spins when the unit is cooling.
What not to do
- Do not spray water or cleaners into the unit or onto the fan.
- Do not reset it over and over. If the code comes back, call.
- Do not run it without the filters.
- Do not add refrigerant yourself. It requires certification, and low refrigerant means a leak.
When to call an HVAC technician
- The light blinks again after a reset.
- It blows warm air with clean filters and the right mode.
- Water drips from the indoor unit.
- There is ice on the outdoor unit or the copper lines in cooling mode.
- The outdoor unit does not start or makes a loud noise.
Frequently asked questions
Why is my mini split blinking?
A blinking light is usually an error code or a filter reminder. Count the blinks or read the code, look it up in the manual and try a reset. If it comes back, call a technician.
How do I reset my mini split?
Turn it off at the breaker or the outdoor disconnect for about 5 minutes, then turn it back on and start it from the remote. Many units also have a small manual button under the front panel.
Why is my mini split running but not cooling?
Often the wrong mode on the remote, dirty filters or a blocked outdoor unit. Low refrigerant, a bad sensor or a failed part need a technician.
How often should I clean mini split filters?
About every 2 to 4 weeks while you use it, more often with pets or dust. Rinse them with lukewarm water and let them dry before you put them back.
What does the snowflake mean on my mini split remote?
It is cooling mode. The sun is heat, the drop is dry mode, which cools only a little, and the fan icon only moves air.
Can I clean the inside of a mini split myself?
Only the filters. The coil and the blower wheel need a deep cleaning by a technician, usually once a year, especially if it smells musty.