How about his? This is a combined electricity/gas bill from Contact. Most of the gas charges were from a US sourced (in the house when I bought it) gas fired fireplace style heater which sends more heat up the flue than into the room.
After that I stopped using it, moved a column heater into the room and then had a heat pump installed! The differences in running costs were major.
Had a similar experience at on of my uni flats.
Had a gas fired open fireplace that we thought was pretty awesome until we got the bill the first month we used it. Eventually found there was a switch to force air around the back of it, to avoid nearly all of the heat going up the chimney. But we had already concluded that heating the large lounge / dining area of a drafty old villa wasn't viable for students.