"I heard Aaron say, 'What's that noise?' and next minute it was like a bomb going off and there was a lot of smoke," she said. "I came down and I thought he was dead. He was just lying there." She had managed to pull her husband out of the kitchen and started screaming for an ambulance.
"There was a lot of blood and cuts. I kept saying, 'Get wet towels, get wet towels'."
She said Mr Seymour was initially unconscious but woke up complaining of a sore neck. "He was talking, he could breathe. He was a mess. You wouldn't recognise him. But he knew his name and he knew his age so that made me feel a bit better." It was not long before her house was full of neighbours, firefighters and ambulance officers all doing their part to help.
Ray Parr was standing on his deck a couple of houses away when he heard the explosion and was first on the scene.
He raced through the neighbour's property and heard Mrs Seymour screaming for somebody to call an ambulance.
Mr Parr had got on a phone to the ambulance service and went inside to see if he could help.
"It was pretty traumatic. It was all dark in the house because it blew all the fuses. We got torches and all that.
"We were trying to get a hose in because the ambulance said to get running water on him. We just had people shuffling wet towels on him."
He said Mr Seymour was badly burned from his shoulders up.
"He's lucky to be alive."
Neighbour Ray Parr was first on the scene of the explosion and helped take care of the injured man.
Mt Maunganui St John operations team manager Gary Bishell said Mr Seymour sustained spinal injuries, burns to his face, neck and head, and had fragments embedded in his body.
He said the kitchen was "unrecognisable" after the explosion.
Mrs Seymour said her husband underwent surgery for deep wounds, was suspected to have a neck fracture and had burns to nine per cent of his body, a third of which were severe.
He was expected to be brought out of the induced coma last night.
Doctors were still considering moving him to the burns unit at Waikato Hospital.
Mount Maunganui Fire Brigade senior station officer Roger Pickett said firefighters believed the explosion was caused by an over-heated chip heater.
He said it was an unusual event.
It appeared there had been a leak in the pipe-work or the system, so the homeowners had cut off the water supply but had not drained the excess water from the system.
As a result, when the chip heater was used, the remaining water inside the pipe began to heat up.
"When water changes state from a liquid to a gas it expands 1700 times," Mr Pickett said.
"It's a condition called BLEVE: boiling liquid expanding vapour explosion."
Mrs Seymour said the family had had the heater repaired on Monday and had used it since then without incident.
Mr Pickett said the strange noise Mr Seymour heard would have been pressure building up.
"It would have made a high-pitch whistle sound with the steam building up so he went to investigate it and now he's in hospital."
"He suffered quite severe injuries," Mr Pickett said.
"There was a stove oven next door and that had been demolished."
Mr Pickett said Mr Seymour was lucky to have survived.
"The back of the chip heater is 15ml cast iron and the explosion blew that up and there were big clumps of it that had gone from the kitchen into the dining room.
"If someone had been in the path of that, it would have killed them."
Bay of Plenty fire safety officer John Rewi said wetbacks were usually a safe way to heat homes when properly installed and maintained.
"There's no problem at all with them.
"I've had one in my house for years."
