"Blimmin heck, it could have been a disaster."
Mr Coneybeer said the woman was getting smoke alarms after the incident.
Firefighters will be looking at the type of heater to see if there have been any issues with others around the country. He said the house was modern and the heater was new.
There was not much damage, and the fire hadn't burned through the gib, he said.
Firefighters were also busy on Tuesday evening, first with a microwave fire at Acacia Park Motel at 4.30pm.
The fire was out before they arrived.
A fire callout to Te Awhina came after someone lit a fire in some bedding, Mr Coneybeer said.
The callout came at 7.15pm, but the sprinkler system put the fire out.