Neighbours have told how the man, known as locally as Jerry, woke up on the burning couch, but was unable to escape his flat.
Firefighters discovered the man dead in his ground floor of the large three-storey home in Beeches Road in West Bromwich.
West Midlands Ambulance Service were called, but were turned away by police, who said the man, believed to be in his 50s, had died.
Helen Clarke, aged 26, lives in a house next door.
She said: "We saw all the emergency services come to the house and wondered what was going on.
"We were then told that Jerry had died, it shocked everyone. Some of us had only seen him earlier in the day."
She added: "I knew him as a neighbour. We would say hello, everyone knew him because he was always about.
"He was a nice guy, it's a shame what happened."
A 21-year-old man, who did not wish to be named, said: "I had gone to drop something off at my brother's house next door when I saw him through the window on the sofa on the evening before he died.
"He looked fine, I couldn't believe it when I heard what happened.
"He was a nice man, someone who liked his drink, but always friendly and enjoyed a laugh."
He added: "I heard he fell asleep on the sofa and the fire spread from a heater. The room was taken over by smoke and he couldn't get out."
The fire happened last Monday.
Sandwell Councillor Ian Jones, executive member for the economy, said a council officer's report had said the man had tried to escape through a window before he died.
Councillor Jones said: "It is upsetting, any loss of life is tragic. Reading about what happened is particularly sad.
"My thoughts go out to his family."
Firefighters managed to conceal the fire to the apartment, before leaving the scene in the early hours of the morning.
Investigators confirmed the blaze was accidental, after being started by an electric heater and spread to a sofa.
The fire and police services have now handed the investigation to the coroner.