After calling several plumbers in the area to get price quotes on the installation of a Rinnai tankless water heater, I decided to go with PSNC Energy, a large natural gas utility in the southeastern U.S. Their prices were competitive, and I felt most comfortable having the gas company work on the gas lines in my house.
The total cost was $2500: roughly $1100 for the unit itself, and $1400 for installation. Note that the installation cost was $200-$300 moe than usual because we wanted the new water heater relocated from the attic to the basement. The installation was performed this past Wednesday and the PSNC crew did a great job. They had to tap into the main gas line, insert a T fitting, and run a gas line to the tankless unit. The gas flow rate needs to be higher for a tankless unit because the instantaneous heating requirement is often larger. They installed a special regulator close to the unit to control the flow of gas. They also of course had to tap into the hot a ...