As and electrican I recently ran into a problem that should be addressed before you even by a tankless WH. One of my customers purchased one of the web for $400.00, thinking it would free up space in his townhouse. What he didn't realize was that in order to install it, he would have to upgrade his electrical service to handle the load. I estimated $2500.00 to replace the service and install the TWH. Alot of money and trouble. Make sure you check out all requirements before you buy.