A 12-year-old boy has saved his hearing-impaired mum from a fire that destroyed their Melbourne home.

The boy woke his mum up when the fire broke out in their Melton home on Friday morning, police said.

Local police were patrolling the area and pulled up outside after noticing smoke coming from the house.

The boy escaped unscathed but his mother, aged in her 40s, was taken to The Alfred hospital for treatment for burns.

The house was well alight when firefighters arrived at 10.20am, the CFA says.

The woman suffered burns to her back and hands but was in a stable condition, an Ambulance Victoria spokesman said.