I'm a DIY engineering-educated type of person, but running a long gas line and learning everything about Tankless water heaters was getting complicated - time to call the pros. I got three estimates. Rod, amazing Rinnai-recommended and certified tankless water heater installer accurately estimated and then verified all gas line and water calculations. Tankless was not the cheapest, but easily demonstrated they had the most experience and got the job done right the first time. I've had 0 issues. We just have endless hotwater and lower bills. Rod ran the gas and water lines in a way that was considerate of future expansion plans for additional faucets and gas appliances that we might install in the future. Tankless worked with Washington Gas to update the meter and worked with the inspector to make sure everything was to code. No more cold showers, carbon monoxide, wasted energy, risk of broken water tanks: 8/2014: 14.5 therms (2 adults, one kid) 8/2015: 15.6 therms (2 adults, one baby) 8/2016: 9.3 therms (2 adults, one kid, one toddler) Rod is SUCH a legendary installer that when I mentioned his name to the Washington Gas technician who upgraded the meter, the technician knew Rod by name and even came back to say hi on the day of the installation. He spoke as if ROD was the best tankless water heater installer ever - it's probably true. Additionally, Tankless, the company, was excellent and helped my secure three seperate rebate/discounts. If you need a Tankless Water heater, I strongly recommend Tankless Concepts. If you don't get a live person when you call the first time (like me), just leave a message! The first time I called I didn't get a live person and moved on to the next company I had in my priority list - but I should have left a message the first time.