I had an excellent experience with Tankless Concepts.  They came in and replaced my old tank water heater with a Rinnai tankless a little over a year ago.  They were completely forthcoming with all the details of the install from how he made the decision of where to install the exhaust (with my input) to the breakdown of the costs.  All permits, inspections, and Washington Gas interactions were handled professionally and efficiently.  My gas line from Washington Gas had to upgraded to accommodate the new tankless heater.  The actual install took less than a day and couldn't have gone smoother.  The workmanship is beautiful.  And now, more than a year later, I have had no problems and have been very satisfied with my decision to install a tankless water heater.

Work Completed: Installation of New Tankless Water Heater If you're thinking about a tankless water heater, this is the company for you.  Not only do they know their stuff, they care about their customers and also try not to oversell you things you may not need. In short, without a slightest reservation, I highly recommend this company.  - Tae K of Vienna, VA

I was very favorably impressed by the service. I left a message at about 9:30am to report the problem, received a callback at noon to let us know that a technician might be able to get to us before 3:00pm. At about 3:00, we received a call that the job he was on had taken too long for him to reach us, but that he could either come at 4:00 or on the following Monday, our choice. We opted for that afternoon, and he arrived promptly at 4:00, went immediately to work, and finished by a little after 5:00. The technician was very professional and very pleasant, explaining to me exactly what he was doing as he proceeded to analyze and fix the problem and then do a general maintenance checkup on the unit. We will certainly hire this firm for regular maintenance and would hire it to replace the unit if we decided we wanted another tankless water heater.