All Superior Bidet models function without electricity or batteries. The warm water comes from a warm water line. Depending on the layout of your bathroom there may be a warm water shut off valve near the toilet. Otherwise, you will most commonly find the warm water shut off valve for your sink which can be used to supply warm water to the bidet attachment. Once you locate the warm water shut off valve you would then attach a metal t-adapter which would split the water between your sink in this case and the bidet. Lastly, you attach the supplied hose from the t-adapter straight to the bidet and voilà, you now have warm water. All of the parts needed for a proper installation are included. See the instruction manual in the box or on the website for instructions.