Pure Plumbing advertises 24/7 response. I called on a Saturday night and immediately an was able to set up an appointment immediately. Steve, the plumber, arrived on time. Pure sends out a message with a photo of the plumber and the ETA, followed by a notice when the plumber is in the neighborhood. Work began quickly with disposal of old heater followed by modification of both gas lines and plumbing to accommodate the tankless heater. The work required was extensive, as the gas line had to be changed to a larger diameter pipe. Location of the gas line was similarly changed to get past the garage door. Work took approximately a day. Given the complexity of the modifications, Work was done quickly and efficiently. New heater needed only cleaning of internal filter, then worked well to all parts of a 3000 sq. foot home. Our only delay was in securing city approval for the modifications--largely due to problems with the gas company, who was unable to schedule hook-up of new gas line in a timely manner. Gas company rep who did the hook-up was excellent. City inspector commented on high quality of plumbing work. Garage was cleaned following work. Tankless heaters are expensive, but costs fell within competitive range.