Tips for cleaning an exhaust fan

Here's a test: Hold a tissue up to the grille where the air enters the exhaust fan in your bathroom, kitchen or attic. Turn on the switch. If the tissue stays tight against the grille, that's good. If the tissue flutters or falls off, that's bad — your exhaust fan has become an exhausted fan; dirt may be the problem. Attic and below-ground room fans should be cleaned once a year; bathroom and kitchen fans, every six months.

• Turn the switch off. Unplug the fan or disengage the circuit breaker.
• Remove the fan grille and wash it thoroughly in warm water and dishwashing liquid, then rinse and dry. A kitchen exhaust fan will also have a filter that needs washing.
• On many models, you can remove the fan and motor by unscrewing the mounting bracket and unplugging the cord.
• Whether you remove them or not, vacuum the fan blades using the crevice attachment, then wipe them off with a damp cloth. You also need to vacuum and wipe the inside of the housing.
• Clean the motor and other dusty parts with a stiff paintbrush.
• If you notice frayed wiring or if the fan doesn't work, call an electrician — don't attempt to fix it yourself.

• Wash the filter in a range hood exhaust fan. This filter, usually aluminium, is for catching cooking grease.
• Remove it and wash it in the dishwasher or in a solution of hot water and dishwashing liquid.
• Don't use ammonia, which will darken the metal.
• Rinse, dry and reinstall the filter.
• Rangehood fans that recirculate the air, rather than venting it outside, have a charcoal filter that must be replaced every six months.
• It's not just a matter of not working efficiently — very dirty exhaust fans have been known to start fires.
• Take extra care if you're renting, because tenants come and go, and no one thinks about cleaning those dirty fans, which could leave you at risk.