Traditional hot water tanks need almost no maintenance. The tankless ones, however, need to be maintained – at the very least – every two years. When you boil water, there is a high chance of calcium buildup. In a tankless water heating system, this happens inside the heat exchanger tubes, inhibiting water flow, dropping the water pressure and reducing system efficiency. To remove this buildup, you need to pay the technician at least $200 – once every two years – to flush out your system with some sort of an acid and using special valves and other relevant equipment.
Taking the maintenance costs into account, not only you are left with no savings but you actually have to pay from your own pocket to have your system run properly. And do keep in mind that if you do not keep your tankless water heater maintained, the tubes will eventually become clogged and not only does the water pressure drop drastically, but so does the system efficiency!!