Yeah, this one's common and usually not a big deal. It's probably the thermal sensor or the Total Stop System.
First, check for the Total Stop System (TSS). This is a normal feature. The motor shuts off and goes into standby during inactivity or as soon as the unit is pressurized. Just squeeze the trigger again to restart it.
If it's not the TSS, the thermal sensor likely tripped. The motor protects itself from overload. If it gets too hot, it shuts down.
- Turn the machine off and unplug it.
- Leave it alone for at least 5 minutes to cool down completely.
- Plug it back in and try again.
If that didn't work: Check that your home's mains voltage matches the spec on the machine's model tag. A significant voltage drop can cause this. Also, ensure the water is turned on and flowing before you start the machine—running it dry damages the pump.
Heads up: If it keeps happening with normal use, there might be a leak in the pump or spray gun, or the trigger mechanism could be faulty. In that case, you'll need to call Sun Joe service at 1-866-SNOWJOE.