These are the most abused machines in any garage, and they take it well until they meet one of three things.
Ash — never
Covered in the FAQ above and worth repeating, because it is the failure that burns houses down. Use an ash vacuum.
Fuel, solvents and anything flammable
The motor has brushes and brushes spark. Petrol vapor in a drum is a bomb, not a hazard.
Water, and the float
Every machine has a float that cuts suction when the drum is full. Do not ignore it and do not defeat it — water reaching the motor is the end of the machine. When suction dies abruptly during wet pick-up, the machine is telling you to empty it.
Fine dust needs a bag and the right filter
Plaster and cement pass through a standard pleated element and out into the room. Use a renovation filter and a fleece bag, and use a cyclone separator if you do this often.
After water
Empty the drum, wipe it, and leave it open to dry. A closed drum with a liter of dirty water in it smells within two days, exactly like a floor washer.
The questions we hear
Can I vacuum ash with a wet and dry vacuum?
No, and this is the one that causes fires. Ash from a stove holds live embers for days, the fine ash passes straight through a standard filter into the motor, and an ember in a drum full of paper dust and sawdust does exactly what you would expect. Ash needs a dedicated ash vacuum with a metal drum and a metal hose.
Do I have to remove the filter for water?
It depends on the machine, and the manual is the authority. Some designs pick up water with the flat filter in place; on others, water through a paper-based element ruins it permanently. Check once, then make it a habit.
Last reviewed 2026-08-16
