We have a Rayburn (like an Aga, but less elite) that came with the house and which acts as our water heater during the Autumn-late Spring period. It also provides a low level background heat so we don't have to use our central heating as much.

However, it runs on domestic heating oil and the monitor keeps flashing at us to refill but the prices are sky-high. We are probably going to have to turn it off early rather than pay through the nose for the oil, but that means having to rely on an immersion heater for hot water which is also expensive. We have an electric shower and a dishwasher so we'll only need hot water for minimal washing up, wiping the kitchen counters etc., but still.