The Tank › Going to on-demand gas heater, what to do with tank? › Reply To: Going to on-demand gas heater, what to do with tank?
Hello, The normal bypass valving is a bit different than what you show. I’d put a valve on each side of the heater and then extend those lines up to a horizontal line. Put a valve in the horizontal line between the two verticals. Now you have a system that lets you use the tank (or not) and lets you bypass and drain it as well.
Another thought is to put a tankless heater to serve only the tub, and leave the rest alone. This likely will give you better hot water service for the majority of the fixtures.