We changed our heating before Christmas, what a mistake, you cannot buy back boilers now so we had to do something else which means I don't have an immersion heater and the heat from the back boiler went through the middle of the house, gone, so now the house it cold, never felt so cold in my life before, costly mistake, we should have explored other avenues
LM
We’ve never had a back boiler so afraid I can’t comment on that, but we have a combi boiler - our second one and combined with that, we replaced the double glazing and had cavity wall insulation fitted. Our gas usage is less than pre the changes and with the windows being A or A+ ones, when the sun shines the heat comes in and stays. Also when the radiators are on, the heat stays in for longer, esp at night we’ve noticed. I presume you’ve done everything you can to insulate your type of house? I resisted cavity wall for years because of the scare stories around, but the firm that did it, did the pre drilling and then showed us the images of our lovely clean cavity with their endo camera before they filled it.