Returned to install new 50 gallon water heater, 4.5 gallon expansion tank, and new PRV. Removed and hauled away old water heater. Installed new 50 gallon water heater. Plumbed in both water heaters in parallel system. Both water heaters have ball valves on hot and cold side to isolate water heaters in case one goes down. Also reworked the flue. Installed new PRV and expansion tank. Set both for 75psi. Checked for leaks and no leaks detected. Also augured kitchen drain line for customer.