Replacing My Old Tank Water Heater With a Tankless System: A Full One‑Day DIY Project

I replaced my old tank water heater with a high‑efficiency tankless system, a full‑day DIY project involving permitting, electrical wiring, gas line reconfiguration, copper pipe soldering, drilling new wall vents, and installing a condensate pump. This post walks through every major step, with photos showing the new intake/exhaust vent, custom gas sediment trap, vent routing, and the final…