Firefighters said the 29-year-old man was burned on nearly 35 percent of his body.
The incident happened on the 2900 block of North Lowell Avenue at about 2 a.m.
The man, his wife and daughter were in the house when the explosion happened, but only he was injured.
The explosion blew out the windows of the house.
"I heard an explosion and the windows shook, felt like an earthquake. I come outside and I saw the glass on the ground and thought maybe it was a car accident until I noticed the windows exploded out of the house," said neighbor Christopher Tuttle.
Area residents said the man may have been trying to light a pilot light, but investigators were not sure of the cause of the explosion.