Richard Hall vividly remembers the moment he heard a raging bushfire approaching his home, comparing the "frightening" sound to a blowtorch.

Key point: Richard Hall's Bell home was saved by two firefighters as the Grose Valley fire hit the small village

Richard Hall's Bell home was saved by two firefighters as the Grose Valley fire hit the small village Mr Hall heard the bushfire approaching his house like a "freight train"

Mr Hall heard the bushfire approaching his house like a "freight train" Mr Hall said this was the worst bushfire he'd experienced in 30 years in Bell

Mr Hall lives in the small Blue Mountains village of Bell, which was devastated by the Grose Valley bushfire on Saturday.

Mr Hall was one of lucky ones, as firefighters managed to save his home.

Two firefighters from Springwood station advised him to leave but Mr Hall decided to stay.

"I'd heard this roaring sound like a freight train coming roaring over the hill. They said just go. I thought no, I can't leave the place," Mr Hall said.

"Eventually they managed to keep the hoses trained on the roof and all around, and eventually managed to save it.

"I'm so grateful to the guys who saved it. I'm still here for Christmas thanks to them."

Mr Hall has lived in Bell for 30 years and has seen numerous bushfires but admitted the blaze on Saturday was the worst one he'd seen.

"I've seen bushfires come and go, but nothing like this. If you look closely the metal has just melted. It took everything in its path."

Mr Hall said he will never forget the moment the bushfire hit.

Richard Hall described hearing the roar of flames. ( ABC News: Sarah Hawke )

"It's a scary feeling. Frightening when you hear the sound coming. It's like a blowtorch. The whole sky went black and the sun went out. The smoke was just incredible. I'll never forget it.

"I built this little brick barricade to climb into, but if the house had gone up the heat from that would have been way too much."

An assessment team checks a destroyed house in Bell. ( ABC News: Sarah Hawke )

Fire crews on Monday were assessing the damage done to Bell by the bushfire

There had been concerns over a missing man from a remote rural property on the weekend, but he was found safe.

Blue Mountains Mayor Mark Greenhill posted on his Facebook page on Sunday that a number of houses had been lost in Bell and expressed his "deepest thanks to all our wonderful, tired and brave emergency services".

About 100 homes have been lost in bushfires across New South Wales since Friday, the state's Rural Fire Service says.

At least 20 structures are believed to have been destroyed in the small village of Balmoral in the Southern Highlands, a location devastated by the Green Wattle Creek fire.

The RFS said at least 829 NSW homes had been lost so far this bushfire season.