Generally speaking, electric heaters are thought to be more expensive to run than gas-powered heating solutions, given that electrical running costs per hour tend to be higher than gas. What’s more, off-peak electricity tariffs can also enhance energy bills depending on the electricity supplier.
That said, there’s a wide variety of factors that can influence electrical running costs, with the size and insulation of a room amongst them, as well as the number of electric radiators or alternate electric heating solutions present.
Plus, the location of the property housing the electric heating devices can also prove a differential, as well as the type of house.
Ultimately, all factors need to be considered on a case by case basis, and your budget taken into account, to determine whether or not electric heaters should be thought of as expensive to run.