Disaster has been avoided after a person called Fire and Emergency when hearing their neighbour's smoke alarms going off.
Fire and Emergency were alerted to the incident on Paterson Street at around 7.30 Sunday morning.
Whanganui station officer Shane Dudley said a smoke alarm detected smoke in the laundry area of the house, which was caused by embers placed in a plastic bucket after someone had cleaned out the fireplace.
The property suffered minor damage and no one was at home at the time of the callout.
"It's a timely reminder for people in Whanganui to take care with hot ashes, if you're going to clean out the fire place put embers and ash in a metal bucket or container, cool it down outside and leave it outside."
Dudley said embers can stay hot enough to start a fire for up to two weeks after they were lit.
"This incident could have been a lot worse if the neighbour didn't call, or smoke alarms weren't working.
"It's really important if anyone does hear smoke alarms going off that they contact Fire and Emergency, and since it is the start of winter it's a good time for people to check their smoke alarms are working properly."