Fog machines are great for Halloween parties, special theatrical effects, DJ lighting and more. Fluid-type machines use heat to vaporize a special liquid -- often called fog fluid -- producing a nontoxic smokelike vapor. On occasion, fog machines will clog and need to be cleaned. Every type of fog machine is different, and some require special cleaning by a professional, but many fluid-type units can easily be cleaned at home with a few simple steps.
Unplug the machine and let it cool completely.
Empty the fog fluid tank.
Fill the tank halfway with white vinegar. Plug in the machine and let it warm up to operating temperature.
Run the fog machine for several minutes so that the vinegar circulates through the fluid line and the machine delivers a vinegar mist. Be careful; the vinegar vapor may be very hot.
Turn off and unplug the machine, and let it cool down. Empty any remaining vinegar from the fluid tank.
Fill the tank with new fog fluid, then plug in and test the machine to make sure it works properly.