A Prebbleton family arrived home from the movies on Saturday night to find it ablaze.
An electrical fault in a fridge in the garage caused the fire which swept through the double garage, two bedrooms, hallway and bathroom.
Two cars were destroyed and the Trices Road house was extensively damaged.
Luckily, two dogs that had been sleeping in the garage during winter were in their kennels outside.
The devastated owners, who did not wish to be named, said they arrived home from the movies at 8:20pm to find their house on fire.
"We couldn't believe it. The house was in flames. We couldn't do anything but sit there and watch. It is totaled. We are going to have to clear everything and start again. We are devastated, to think a fridge could have caused this much damage. We had a fridge in the garage."
A neighbour standing at her kitchen window said she saw a "glow" coming from the well sheltered property at about 8:15pm.
"I thoughts it was a bonfire or a hedge fire at first. But then I heard sirens. I started walking down the driveway. It was amazing. You would think it would have been burning for hours. The one thing I was concerned about was that it had taken hold of their house so quickly.
"I was petrified because all I could think about, at the time, was what if they (the family) are inside. There's basically no house left. It's just so lucky they are alive," she said.
Fire safety officer Mark Thomas said fires caused by fridges are rare.
"It was lucky that no-one was home. The fire was caused by an electrical fault in a fridge that was in the garage. It was lucky the owners were out at the time and weren't asleep in the house. Their bedroom was destroyed. It could have been much worse."
Two appliances from Lincoln and two tankers attended the blaze which took more than five hours to put out.