Fire and Rescue NSW (FRNSW) Inspector Anthony Hojel said firefighters had attended two emergency calls to houses on fire in the last week where the smoke alarms had failed to operate.

"Only working smoke alarms help save lives," Inspector Hojel said.

"A fire can take hold in just three minutes, filling your home with deadly smoke. A working smoke alarm gives you vital seconds to get out before you're overcome.

"A smoke alarm with a flat battery is just as risky as not having a smoke alarm at all. That's why you should change your smoke alarm battery."

FRNSW data reveals 13 per cent of the 3900 home fires in NSW last year occurred in properties with no working smoke alarms.

READ ALSO:

Devastatingly, more than half (56 per cent) of fatal house fires between 2000 and 2014 had no smoke alarms present. The majority of these deadly fires also occurred between midnight and 6am - when people were asleep.

FRNSW recommends householders install photoelectric, interconnected and hard-wired smoke alarms.

"In addition to the legal minimum requirement of one smoke alarm per level, FRNSW recommends having smoke alarms installed in all bedrooms for maximum protection," Inspector Hojel said.

Smoke alarms are also mandatory for all caravans, campervans, and other movable dwellings where people sleep - even if the vehicle is kept off the road.

Inspector Hojel said a working smoke alarm and a home escape plan could save you, your family, pets and possessions in a fire.

"If you don't have smoke alarms, don't gamble with your family's life by waiting to install them - you should do it now," he said.

If you need help checking or replacing the battery in your smoke alarm, contact your local fire station and ask about the Smoke Alarm and Battery Replacement (SABRE) program for seniors and people with disabilities.