We have no boilers that match your criteria. You'll also get a free tado smart thermostat and installation worth £249, so you can control your heating from your smartphone. If your boiler is g-rated for energy efficiency it's a good idea to replace it. Cup peroxide, 1/2 cup baking soda - wait 60 minutes. According to your annual income and the type of boiler you want to install, your allowance earnings will be different find below a table summarizing it. Are tree roots blocking your pipes?.