See also Bathroom redo.
The Bathroom redo project wasn't just about the bathroom, since I planned to replumb the entire house in PEX and change my water heater as well. It's just that the most visible change would be in the bath.
However, I also wanted to go tankless with my water heater for two reasons: 1. My existing tank water heater was at the end of its service life and 2. I could recapture scarce interior space in my home by moving the new tankless heater up into the attic.
My new water heater is a Takagi T-K Jr tankless water heater. It was a bit more difficult to procure this heater than buying a Bosch from Lowes or a Rheem(?) from Home Depot. Nonetheless, I made the effort based on professional plumbers' inputs that extolled the virtues of Takagi over Bosch and Rheem, a refrain I heard over and over again - often enough to believe it. While the day to day benefits remain to be determined, from a do it yourself perspective it's exactly the opposite: Bosch has it over Takagi. Here's why:
1. For Bosch the required 3" double insulated stainless steel vent tubing is conveniently available at Lowes, the same place I'd purchase the heater. The 4" Cat 3 stainless vent tubing for the Takagi required a trip to a full service plumbing supply store - a marvelous place indeed, but not incredibly convenient.
2. The Bosch uses water flow to spark its ignition. Takagi requires a hard wired electrical connection (though for temporary testing purposees changed it to a plug).
3. Clearance issues. I discovered to my chagrin that the combustible materials clearance on the Takagi 4" vent pipe is and additional 4" from the pipe. It is only 1 inch for the Bosch double wall 3" vent pipe. This required that I widen and reinstall the roof vent from the old heater instead of just re-using it.
These issues combined made the Takagi more difficult to install from a do it yourself perspective than I think the Bosch would have been.