The Lehigh County coroner's office has identified the man as 58-year-old Anthony F. Suida.
Firefighters were called to 847 N. Jerome St. around 8:15 p.m. Wednesday.
Firefighters were able to knock the fire down quickly, but Suida was found inside the home, police said.
Officials are trying to figure out exactly when and how Suida died, but the coroner's office said Thursday his death is not related to the fire.
An autopsy was performed Thursday morning. The cause of death is pending toxicology results.
The initial investigation revealed the fire was started accidentally by a portable electric appliance, a fire official said.