A small three-bedroom weatherboard cottage in Vincent Street was extensively damaged after candles in the bathroom caused the fire at 9.15pm.

A father, mother and young child were not injured in the fire, escaping after a neighbour spotted the fire.

Sergeant Warren Groves of Ararat said the couple were bathing their young child in the bathroom and had candles alight on the windowsill with the window slightly ajar.

"They left the room to dress the child and the power went out," he said.

Sgt Groves said the father went to check the powerboard but the power continually went off.

"A neighbour putting out bins at the time saw smoke coming from the rear of the house where the bathroom is. The father was able to get his partner and their child out of the house and the neighbour called emergency services," he said.

Sgt Groves said welfare services were caring for the family.

He said Ararat police attended to direct traffic and assist the investigation.

Sgt Groves said the fire was a timely warning for people to be careful with candles and ensure smoke detectors were working.

"People need to put out naked flames before they leave a room or leave the flame unattended," he said.

"Candles are a predominant cause of house fires."

CFA Region 16 operations officer Ian Morley said the Ararat fire brigade, including 20 firefighters in four vehicles, had the fire under control within 30 minutes.

Mr Morley said the house was extensively damaged.

He said although the fire was not suspicious, CFA personnel would investigate further.