Some vacuum cleaner motor heat is normal and nothing to be concerned about. However, vacuum cleaners need regular cleaning themselves, to retain their operational integrity. If the heat from the motor is sufficient to produce smoke, this is a more serious problem and may signal the end of the vacuum cleaner’s service life.
What causes the heat?
Motors generate heat because motor assemblies have moving parts. The movement creates friction, which warms nearby air. According to Hoover, higher wattage motors are more powerful. This generally means they produce more heat. However, a more powerful motor does not necessarily mean better suction. Usually, vacuum cleaner motors are protected from overheating by thermal cut-out systems.
Overheating due to blockage
A blockage can cause a vacuum cleaner motor to overheat. This is because the motor is having to work much harder to achieve the same suction. Disconnect the vacuum cleaner from the mains. Inspect pipes, ducts, traps and anywhere else dust and fluff can gather. If you cannot reach the fluff by hand, Vax recommends you use a wire coat hanger. Do this carefully so you don’t puncture the hose.
Filters protect vital parts of a vacuum cleaner from dust and dirt. However, dirty filters can cause motors to get hot. This occurs because of an interruption to normal air flow. The Bosch BGL3522GB, for example, has a washable motor protection filter. You need to wash filters regularly to ensure the motor continues to operate effectively. Further, when filters become perished after prolonged use, you need to replace them.
If a vacuum cleaner gets hot to the point where it emits smoke, switch it off and disconnect it from the mains. The smoke probably indicates motor component burnout. If the vacuum cleaner is still within warranty, take it back to the place you bought it from. If it is out of warranty, take it to a vacuum cleaner repair shop or dispose of it in the correct way at your local household waste site.