Customer called us out to checkout a leaking water heater. When we inspected the area we noticed the leak was coming from the expansion tank. The water had leaked into the water heater electrical components so I immediately removed the disconnect to turn power off. I recommended replacing the water heater. The customer agreed to the tankless option so we began work. We removed the old unit and isolated the old recirculating line and capped it off on both sides. We tied all lines back together inside the old utility room. We made connections for hot and cold in the attic above the garage and ran them into the garage. Installed new shutoff, new check valve, new thermal expansion tank. We teed off the 1 inch gas line in the attics and ran into the garage as well and connected to the tankless by installing new shutoff valve, new gas flex, and new drip leg. We ran T&P, condensation drain, and both exhaust and intake to the exterior of the home. We temporarily powered on the unit with a cust