mini split troubleshooting
Mini split is blinking a light or showing an error code
What it probably is, what you can safely check yourself, and the point where it becomes our job.
It is still running, so you have a few days. It is not going to fix itself, and the part that failed rarely fails alone.
What is most likely going on
A blinking light is a fault code, and the specific pattern is how the equipment tells a technician what it detected. The codes are manufacturer-specific and there is no universal chart, so record which light blinks, how many times, and the pause pattern before you reset anything.
Likely causes, most common first
- 1
A sensor has failed or gone out of range
Indoor and outdoor coil thermistors, ambient sensors and discharge sensors all report to the control board, and an open or shorted sensor is one of the most common coded faults. It is usually a modest repair. The code is what tells us which sensor, which is why the pattern matters more than the fact that a light is blinking.
- 2
Communication fault between indoor and outdoor units
Mini splits pass data on the interconnecting cable, and a loose terminal, a nicked conductor, or moisture in a junction breaks that conversation. Installs where the cable was routed without a proper drip loop, or where a splice was made outdoors, are prime candidates. In a wet marine climate, moisture intrusion at a connection is a leading cause.
- 3
Pressure, overload or protection trip
The board will lock out and flash a code when it sees high or low pressure, a compressor overload, or an outdoor fan that is not turning. Repeatedly clearing that lockout to force another run is how a protection event becomes a compressor replacement. Treat a repeating code as a real fault, not an inconvenience.
- 4
Voltage supply problem
Low or unstable supply voltage, a loose lug, or a marginal connection at the disconnect can produce codes that look like equipment failure. This is worth ruling out on older Bellingham panels, and any correction on the supply side is work for a licensed electrical contractor rather than for us.
- 5
Normal status indication misread as a fault
Some models blink or change indicator colour during defrost, standby, timer operation or filter reminders. That is status, not a failure. Your manual distinguishes the two, which is a reason to keep it rather than an excuse for the manufacturers making them so similar.
What you can safely check yourself
Work down the list before you book anything. Plenty of calls end here, and we would rather you keep the money.
- Write down exactly which light blinks, how many blinks, and the length of the pause between groups, then photograph the display.
- Find the model number on the indoor head label and on the outdoor unit label and note both.
- Look up the blink pattern in the manual for your specific model rather than in a generic online chart.
- Replace the indoor filter and rinse the washable screens, since some codes are filter or airflow related.
- Reset power at the breaker once, and if the same code returns, leave the system off and stop resetting it.
What is deliberately not on that list
Nothing above involves refrigerant, gas piping, or opening a live electrical panel. Refrigerant work is federally regulated and needs recovery equipment. Gas work done wrong kills people. An energised panel turns a $300 repair into a hospital visit. Electrical work on the circuit itself is done by a licensed electrical contractor. If a step you have read elsewhere involves any of those three, stop and call instead.
When to call us
Call us once you have the blink pattern and the model numbers, which usually lets us arrive with the likely part. Do not keep power-cycling a system that trips the same protection code, because forcing runs past a protection event is how a repairable fault becomes a replacement. Reach us at (360) 592-3824.
Monday–Friday, 8:00 AM – 5:30 PM · Emergency calls answered 24/7
Tell us what it is doing
Describe the symptom and we will tell you what it takes to fix, what it is likely to cost, and whether it is worth fixing at all.
Monday–Friday, 8:00 AM – 5:30 PM · Emergency calls answered 24/7