A few days ago, Megan mentioned the Energy Star tax credit for tankless water heaters. I thought I'd share a few details from our experience in water heater shopping for those of you that might be considering this option.
A few weeks ago, Megan pointed out that there was a puddle of water under our hot water heater and I should "do something about it." I wasn't sure if this was a condensation or a slow leak that we hadn't noticed from before so I soaked up the spill, dried the floor with a fan, and went about my other chores for awhile. When I came back, there as a pancake-sized puddle again. I still couldn't tell where the leak was coming from, though, so I cleaned it up a second time. Checking on it a few minutes later, I noticed that the puddle in the back was a bit muddier and a small bit of rust-colored water was running down the back seam of the heater. As I stood up, I realized that the seam had actually ruptured near the top. A spray of dried mud was clearly visible on the wall behind the heater. I sighed realizing this meant buying a new hot water heater.
The water heater we had was 40-gallon, gas-powered, vented Rheem Fury that was installed when the house was constructed in 1991. In the spirit of "going green," I started searching the Energy Star options at both Sears and Home Depot. There was three replacement Kenmore models at Sears, ranging from $530 to $750.
Of course, Megan and I had been talking about tankless water heaters for awhile. The 30% tax rebate on tankless water heaters ends in December 2010, so we took this as a sign that it might be the right time to invest in this. While Consumer Reports noted that it would take 20 years to see a return on tankless models, I don't think they factored in the 30% tax rebate.
Checking Home Depot, I found the Rheem EcoSense ECO-200PVN. Home Depot offers Rheem models that deliver 5.3, 7.4, 8.4, and 9.5 gallons per minute. However, the 5.3 and 7.4 GPM models can raise the temperature of the water 45 degrees while the 8.4 and 9.5 GPM models can only raise it 35 degrees. The cost comparison shows how these factors counterbalance.
5.3 GPM, 45° = $860
7.4 GPM, 45° = $1200
8.4 GPM, 35° = $1000
9.5 GPM, 35° = $1200
I called Home Depot, was put on hold for about 15 minutes, and was eventually told that they didn't have any tankless units in stock but could order one. I'd also have to call a separate number (1-800-HOME-DEPOT) to arrange installation. This number turned out to be a computer that had trouble understanding me.
Since I really wanted hot water today, I tried calling some smaller places. At Carolina Supply, a guy named Jimmy gave me the scoop. Good news, first. They have the Rheem 7.4 GPM (RTG-74) on clearance for $675! Bad news, they could not do installs. I'd have to find a plumber for that. Calling Willie Saul & Son here in Alamance County, I found out they could do it. The guy I talked to there almost always installs Rinnai units. When I described where my current water heater was, though, we discovered that this was not going to work. The tankless systems require direct venting. This is a special dual-purpose pipe that brings air in from the outside and allows exhaust. (I imagine this is similar to a coaxial cable.) The cost of the piping is expensive and to run it through two-stories (and an attic) would be much more than I was willing to spend.
Ultimately, I had Willie Saul & Son Plumbing deliver and install a Rheem Fury 22V4036F1 (energy factor of 0.59) that was nearly identical to what we already had but twenty years newer. Based on someone's else water heater calculations, I think that the old unit had an energy factor of 0.49. Based on data from the California Energy Commisssion's Consumer Energy Center, I estimate the new unit will only save me an extra $27.5 per year.
So much for living in the green future...