Just saw this on one of the big box store websites. They have an electric tank less water heater. Says it is 80 AMPS. If you have 100 Amp service in your Circuit Breaker Panel, and you have more than half of that used up, what do you need to do , if you want to go the tank less electric water heater route? When I read the specs on it, it makes me wonder how much electric that thing really uses and what the electric bill would be per month with that ! 27 KV it says on it.