Friends are now organising for donations to be made to Mr Boswell and his wife Vickie, saying John had been there for the community for more than 25 years and "it's our time to help him".
Friend Peter Anderson said Mr Boswell was one of the leading fire officers in the disappearance of Aisling Symes back in 2009, and regularly responded to life and death emergencies.
"You can see him at the station when a call comes in, whether it's a fire, medical, flooding or even to assist a cat up the tree," Mr Anderson said.
"John and his family have lost everything to the fire and with a family they need all the help possible."
Mr Boswell was last night still coming to terms with the loss of his home but said he was buoyed by the support.
"I've had firefighters messaging me from all over the country. My phone is inundated," he said. "It's a humbling thing."
"I've been to thousands of these but to be standing there thinking this is mine, this is my house, it's a surreal feeling."
Mr Boswell said the way the children were able to react showed the importance of smoke detectors. "If it was at night in a house with no alarms there would have been a totally different outcome."
The family were staying with Mr Boswell's parents but would need to find a rental house for the next six months.
They were taking it "day-by-day" at the moment, he said.
"The kids, and my wife, are dealing with it as best they can. We're all a bit overwhelmed."
Investigators said the Fire Service was called to the Boswells' Sungrove Rise home around 1pm after a neighbour phoned in to report smoke and flames coming from the property. The cause of the fire is still being investigated but it is not thought to be suspicious.
• Anyone wanting to help can drop off items at the Henderson Fire Station between 5pm and 7pm, or donate to the Westpac account arranged for the family: 03 01460188210 00.