New Gas Lines and Copper Plumbing over the Memorial Day Weekend. Installing a new tankless water heater and relocating to a different place required re-routing several pipes. In addition, I ran a gas line up into the attic for next year's project of moving the Heater/AC to the attic and freeing up a needed closet.
Step #1: Remove toilet from no-longer used water closet to make room for tankless water heater. This photo is the drilling out the cast iron sewer connection (they welded with lead & oakum in the old days).

Step #2: Installing 3" PVC exhaust & intake for the Tankless. This runs thru the attic and then down to the appliance. It vents to the outside up on the roof area.
Finished Roof Vent for Tankless:
Step #3: Re-routing Gas Lines; New line for Tankless, Line for relocated stove, new line up the wall to the attic for future relocation of heater to attic. Under the house is really spacious
Step #4: Copper plumbing for new tankless, pot filler behind stove, and lines for kitchen island
Me, after several trips under the house - Uggg, I'm too old for this.
Tankless Installed - It works!