Replace old back boiler...

TalkingChair18

Hi we have a post war house with a back boiler that runs from the open fire to  boost our hot water tank which in the main is run by immersion -  so expensive! Our heating is old night storage - would we be wise to remove the back boiler and replace hot water tank with a pressurised gas cylinder and stick with new night storage. We don’t want to go to the expense of installing central heating as gas boilers are to be outlawed and oil is expensive...Any advice or similar experience is welcome. Hoping to do a loft conversion next year so it would be a good time to sort the heating out. Thank you