Emergency services were called to the Chardonnay Drive home about 2.55am on Thursday.

The blaze appeared to have started in the roof of the brick building and spread to other areas of the home.

The occupants managed to escape the property without injury.

Firefighters spent several hours on scene and the incident was declared safe about 4.15am.

A fire investigator examined the property in a bid to determine the cause.

CFA duty officer Trevor Ebbels said brigades from Milawa, Wangaratta, Oxley and Bobinawarrah had attended.

“On arrival, the fire was pretty well advanced into the roof of the structure,” he said.

“The damage was fairly extensive.

“I don’t believe the house will be habitable.

“It was occupied at the time and they evacuated safely.”

Mr Ebbels said a product recall of some models of evaporative coolers had recently been issued.

The investigators were looking at the model installed at the home.

“I don’t know if this was the actual model under recall,” he said.

“I’m not going to speculate about the cause.

“We need to determine if that (the air conditioner) may have been the cause, or eliminate that.”

Mr Ebbels issued a general warning for people running air conditioners. 

“If it’s not working properly or there’s a noise coming from it, people need to think about getting that appliance looked at by professionals,” he said. 

Meanwhile police and firefighters have responded to another suspicious grass and scrub fire in Wodonga. 

A blaze was reported at Huon Creek Road about 11pm on Wednesday. 

About 14 CFA vehicles attended and the incident was declared safe after about three-and-a-half hours. 

Police have previously called for information after a series of fires were deliberately lit in the region in recent weeks.