We have an old 20yr boiler on kerosene with rads which are not very effective. We have an electric shower. But we have no on demand hot water at sink kitchen/bathroom when needed. As there are only 3 in the house oil is not looking at being very efficent. Looking at alternatives that can make life easier, ie. undersink on demand water heater kitch/bathroom with panel heaters in rooms that are actually being used. These can be un plugged and moved to any room as needed.
Solid fuel non boiler in kitchen.