I got this LG portable AC for my bedroom last summer and it worked fine, but now in July 2026 it keeps cycling off randomly even when the room isn't that cold. The compressor sounds like it's working then just stops. Could it be a thermostat issue or is the unit overheating?
A portable AC shutting off after a short runtime usually points to either a clogged filter restricting airflow (which triggers thermal protection) or the unit overheating internally. Check if the exhaust hose is kinked or blocked, since poor ventilation makes the compressor work harder and shut down as a safety measure. If the filter looks clean and the hose is clear, the thermostat might be miscalibrated or failing - try resetting the unit by unplugging it for a few minutes, then running it again. If it keeps cycling off after that, you're probably looking at a compressor or internal sensor issue that'll need a technician to diagnose.
I've dealt with plenty of equipment that cycles on and off unexpectedly in lab settings, and portable ACs have similar issues. The most common culprit is actually the thermostat, but not always in the way you'd think. If the unit worked fine last summer and is now shutting off after just 10 minutes, check whether the thermostat sensor might be dirty or positioned poorly. Sometimes dust accumulation on the sensor makes it think the room is colder than it actually is, triggering an early shutoff. Try cleaning the indoor unit's vents and sensor with a soft brush or cloth. Also verify that your temperature setting isn't accidentally set way higher than you think - I know that sounds basic, but it happens more often than you'd expect.
The compressor stopping abruptly could also point to a thermal overload protection kicking in. Portable ACs have a safety mechanism that shuts them down if internal temperatures get too high, usually from poor airflow or a clogged filter. Since yours is a year old, the filter might be genuinely gunked up by now. Replace or thoroughly clean the filter and make sure the exhaust hose isn't kinked or blocked. If the unit sits in direct sunlight or in a confined space without proper air circulation around it, that'll cause overheating too.
One more thing worth checking - refrigerant levels. If there's a slow leak, the system has to work harder and will thermal out faster. This is trickier to diagnose yourself, but if you've ruled out the filter, thermostat sensor, and airflow issues, and the shutoffs keep happening, you might need a tech to check the charge. In my experience, though, it's usually just the filter or a sensor that needs cleaning first.
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