DIAGNOSIS The blinking red light means the vacuum has a thermal overload protection warning. It happens when the motor gets too hot, often from a clog or a full bin.
FIX Turn the vacuum off, unplug it, and let it cool for at least 30 minutes. While it cools, completely empty the dust cup. Then, check the entire path: remove the wand, hose, and nozzle to look for blockages. Pay close attention to the small opening at the bottom of the dust cup where it meets the motor housing—debris loves to get stuck there. Once everything is clear and cool, plug it back in.
IF THAT DIDN'T WORK If the red light is still blinking after a clear path and cool-down, the filter might be the culprit. Take out the felt filter at the top of the dust cup and the foam filter underneath it. Give them a good rinse under cold water (no soap) and let them dry COMPLETELY for 24 hours before reinstalling.
HEADS UP Running it with wet filters will instantly trigger the overload again and can damage the motor. Make sure they're bone-dry.