There was also heavy smoke damage to every room of Ann and David Talbot's two-storey house in Y Wern, Wrexham.

The fire happened just three weeks after Ann, 64, decided to swap her thermostatically-controlled fryer for a conventional chip pan – and just a fortnight after she had had a new kitchen installed.

Speaking less than an hour after the emergency call to the fire brigade yesterday afternoon, Ann said: "We don't normally have a cooked dinner, but my grandson, Levi, 18, phoned and asked could I cook his dinner and then rang back to say could I make more chips for his friend.

"He's usually at NEWI, but he's in the army cadets and was at Hightown Barracks, rehearsing for a presentation."

Ann cooked for the boys while her husband, David, 66, went to install a light fitting for their daughter, Marilyn Hamner, who lives six doors down.

She said: "I must have left the cooker on, but when the boys went, I locked the door and joined my husband at my daughter's.

"I sat down to have a 'cuppa' and he finished work and came home.

"The next thing he's flying down the road like a madman, on the phone to the fire brigade.

"I was very worried about my cats, Ollie and Polly, because they were in the house but they were ok.

"I've only had my kitchen a fortnight – it hasn't sunk in really.

"It will need to be redone and the ceiling will have to come down and I'm finding out from the council tomorrow what needs doing through the rest of the house and phoning the insurers now.

"I had an ordinary chip pan, which I hadn't had for years – I had a thermostat one – but my husband hated cleaning it and my daughter got an ordinary chip pan, so I did too."

North Wales Fire and Rescue Service is keen to use Ann's case to highlight the dangers of chip pans and to urge everyone to buy safer fryers with thermostats fitted that switch the appliance off if it overheats.

County operations manager Ian Williams was at the fire scene with two pumps from Wrexham.

"They had a thermostatically-controlled fryer, but got rid of it because they didn't like it and got a conventional pan and left it unattended," he said.

"The other one would have switched itself off automatically, but this one burst into flames.

"The smoke alarms operated, but there was no one in the house to warn.

"They came back, saw the smoke and discovered a fire in the kitchen.

"We were in the area so were here quite quick, but because no one was here, the fire had been burning a long time, so they've got serious smoke damage to all the rooms in the house, but the fire damage is only in the kitchen.

"The smell will be there for months and months and all because of a simple mistake.

"It's frustrating for us. We don't tell people to buy fryers with thermostats to increase sales of fryers. It's because it works and prevents this kind of damage to people's homes.

"Because of the materials in kitchens, all the chipboard, fire spreads quite quickly and generates black, acrid smoke, which spreads through the house and affects all the rooms and contents.

"If we had out way we would insist every household has a thermostat-controlled chip pan.

"These fires can be fatal. These are lucky they weren't in the house, but if it happens later in the evening and people are upstairs asleep and the fire is downstairs, then their means of escape is blocked and it becomes a rescue."