Strange, all these comments about fires and back boilers.
My mums cottage which was a few hundred years old had one and even though the house had an electric immersion tank, it also had a coal fire and back boiler in the living room.
She would use it as the main source for heating the house and water from when I was little, right up until I was in my late 40’s and only changed over to electric fires as she got older. The large main living room and dining room both had fireplaces as did the large three double bedrooms.
Though one was only in use and in winter we would be shivering trying to absorb some of the heat in a morning from the freshly lit fire before heading off to primary school.
It surprises me everyone appears to have had issues with them, though I can remember a single chimney fire but that’s it.