What they don’t tell you is that hot water tanks are mechanically very simple, require little to no maintenance and last an average of 16 years. By installing a far more fuel efficient electric heat pump water heater, they estimated we could reduce our overall home energy consumption by 11 gigajoules per year, which translates into over 3 megawatts and potentially, hundreds of dollars annually in energy savings. However much to my horror, on further inspection I discovered that unbeknownst to my wife and I, that in order to get out of our current hot water tank rental with Enercare (which we inherited from the previous owners), we would be legally obligated to first purchase our current seven year old tank at a cost of over $1,100.