Clocks go back one hour at 2am on Sunday.

Acting Northern deputy  regional chief Steve Richardson, of the Tasmania Fire Service, said only working smoke alarms saved lives.

He said if people had smoke alarms which used small nine-volt batteries, this battery must be changed every year, and the ideal time to do so was when daylight saving ended.

Mr Richardson said if households had smoke alarms which were hard-wired into their property's power supply, or sealed smoke alarms with 10-year batteries, the end of daylight saving was also a good reminder to check that they worked.

Hard-wired smoke alarms have back-up batteries, which might need to be replaced.

``The best way to ensure that your smoke alarm is optimal, is to replace the battery,'' Mr Richardson said.

``Then regardless of what type of smoke alarm you have, you still need to test it monthly.

``And once or twice a year, gently vacuum the smoke alarm with your duster extension, to keep it in its best working order.''

He said it was critical that smoke alarms met the approved Australian standard.

Mr Richardson said smoke alarms must also be located in areas where people could hear them, even when they were asleep with the door shut.

He stressed the importance of households having a fire escape plan.

``Where do you go?'' Mr Richardson said.

``There needs to be two ways out of every room.

``If fire blocks the door, is there another way out?

``Have a plan and practise it.''