A family of six has had a lucky escape after a fire broke out at their rural property near Merriwa early Wednesday morning.

RFS and Fire and Rescue crews were called to the 4 bedroom home off Idaville Road at 3.30am to find smoke issuing from the rear of the house.

2 adults and 4 children self-evacuated – they were treated at the scene by paramedics for minor smoke inhalation.

The Rural Fire Service says firefighters located a small fire in a wall cavity which spread to the roof but was quickly extinguished.

The cause of the fire is not yet known.