Answer a few simple questions to find the right boiler for your home. For more information or assistance. I currently have an electric boiler which stores hot water once it is heated (no on demand hot water) i want to replace it with an electric combi... If you want to try out the latest development version, you can install it from github the easiest way to do that is by using. Elec boiler output is in kilowatts---1 kw = 3400.