We had a small stove & central heating system, it was dual powered - we had the option to run it on oil or solid fuel (coal &/or wood) and it was a gravity fed system without the need for a pump (handy if you're prone to power cuts
) though not as efficent as todays' pumped systems.
Cost - they might be expensive to run if it was gas or oil powered, and certainly more time consuming that just flicking a switch if it's a solid fuel version, but if you've got a good supply of wood it's not so bad
We currently just have a built in stove for central heating (with a pump
) and really miss the old set up from our last house
HTH
Karen