Homeowner agreed to replace the tankless unit earlier today and came out with parts and new unit to install. After arriving homeowner was at lunch and got home around 120 pm and I began by shutting off the main water meter and drained the whole home. Cut of the power to the unit as well as the gas and cut the water lines and t&p line. Had to cut the 3 inch exhaust to reduce it to 2 inch and then back to 3 inch pipe. Hanged the new unit in place and leveled it and began by piping in the new hot and cold lines with copper. Then pressed them together and connected the t&p line with a drain elbow and put the drip line back into the condensation pump. Once it was all connected I turned on the water and checked for leaks or issues which non were found and I turned on the unit. It worked properly no issues and programmed it and then ran water to ensure there were no codes and hot water is coming out. Homeowner is satisfied with the service provided and wants me to look at his sewage pump loca