Current water heater is located in the attic and is a traditional gas heater. It's 20 years old and need to be replaced. I'm considering a tankless for several reasons, one of which is reducing the amount of water that's contained in the attic. I don't think the efficiency gains are significant enough (break-even point is 7-8 years, so i'm not going to factor that in) to be a pro.

I like the idea of having a nearly endless supply of water, especially when we have guests over and 5 or 6 people need to shower.

relocating the water heater to another location is not cost effective, as the installation of new pipe is significant to put it in, say, the garage.

in the process of getting quotes for both a tankless system and traditional, and i'm guessing i'll be looking at spending around $4k vs $1k here. what are y'alls experiences?

2/1/2013 1:36:47 PM

We went from a gas boiler (house originally had hot water heated baseboards) to a tankless hot water heater 2 years ago. I love the endless hot water since we are a family of 4. the reduced usage of gas is unbelievable. we've gone from several deliveries are year to less than 1 per year. but I'm not sure that going from a gas boiler to a tankless is comparable. But no complaints here.

2/1/2013 2:01:04 PM

I don't have any opinions on one vs the other, I just wanted to say you need to get that water heater replaced PDQ. I work with a fire/water cleanup and restoration company and a lot of our business comes from water heaters. Most are usually right around the 10 year mark it seems like. I'm amazed that thing has lasted that long.

Oh, and anyone who designs a house-plan with the water heater in the attic needs to be punched in the balls.

I am interested in seeing the discussion about this though

[Edited on February 1, 2013 at 3:20 PM. Reason : water]

2/1/2013 3:20:07 PM

I'm guessing your '4k' number is because they have to run a lot of gas pipes? That is REALLY high for a tankless install. Most I have seen somewhere around 1700-3k. And installing a regular water heater is fairly trivial. I bought a unit for $500 and it took my brother and me about 1 hour. BUT... If you don't want the aggrivation, pay someone.

Regarding tankless. We did a big bathroom remodel in which our shower can pump out about 13 gallons a minute. From looking at tankless design, their ability to raise the water temperature depends on flow. And given our flow, I wasn't confident that it could provide a significant delta from the supply water temp to the shower heads at 13GPM.

I would oversize the hell out of it in the event you think you'll actually have a lot of people showing. Carefully look at the technical specs for supply temp deltas before you purchase. Don't rely on the plumber.

[Edited on February 1, 2013 at 3:57 PM. Reason : .]

2/1/2013 3:56:59 PM

We had a Bosch one in the house when we moved in. It was several years old and had a lot of issues. We would be taking a shower and the water would go completely cold and then go back to warm after a few minutes. It was really noticeable once winter came around. We had that replaced with a Rinnai which hasn'thad any problems but I'm notthat high ona tankless even with the better product.

The main issue that I have is that it has to draw in cold supply water for a given amount of time to sense the supply temperature so that it knows how much to heat the water to get to the set temperature. Tis results in a longer time between turning the hot water on and actually getting hot water a the outlet. This can be especially annoying if ou are using hot water and then turn it off for a few minutes. Once the system resets it needs to draw ing cold water again to sense the current temp so you get the remaining hot or warm water from the line and think it is ready to go but then you get a cold bit in the middle before it goes back to hot for good. Additionally the systems typically have a minimum flow before it senses that there is demand and thus isn't good when you only need a trickle of hot water.

2/1/2013 6:47:33 PM

Needing a trickle of hot water hasn't really been an issue in or household. It's one if those ultra rare occurrences that really doesn't factor for us. There is a delay until the hot water gets going and we've noticed reduced water pressure at the kitchen sink, but they really don't signify. No one suffering a cold shower is a pretty big deal for us. It also freed up an entire closet along with the reduction in gas. FYI our install including ripping out the boiler came out around 2500.

2/2/2013 12:42:09 AM

I installed a gas tankless myself. 100% recommend. I got the rinnai R94. I got it for $1000 from amazon + ~$100 in fittings, flex hose, and black gas pipe. you'll need an outlet for the thermostat too. you should be able to diy for < $1250, but I wouldnt spend more than a few hundred on the install, it's trivial

2/2/2013 11:51:48 PM

I currently have a Bosch in the house i rent and have the same experience as hondaguy. Fine all year until winter comes and then it can be hit or miss. Annoying as shit. The service guy has been here at least four times and nothing changes. It can sometimes take forever to trigger. I'll sometimes wait 5-10 minutes, constantly turning the faucet on and off, until the damn thing kicks in.

2/3/2013 10:05:34 AM

^you probably have old pipes with pressure right on the threshold of triggering it. My install came after replacing every pipe in the house with brand new pex.

2/3/2013 11:09:23 AM

^^^

hmmm, i generally tackle most DiY stuff, but one thing I won't mess with is gas lines. I don't know what I'm doing, and it's not worth the risk. Plus, I simply don't have the free time.

that said, I've got a few more estimates on deck, the one I got so far was clearly overpriced.

2/6/2013 12:37:47 PM

Walter White went tankless, I say go for it.

2/6/2013 10:37:02 PM

http://www.consumerreports.org/cro/appliances/heating-cooling-and-air/water-heaters/tankless-water-heaters/overview/tankless-water-heaters-ov.htm

Quote :

"October 2008 Tankless water heaters They're efficient but not necessarily economical VIDEO: Tankless water heaters All videos Heating water accounts for up to 30 percent of the average home's energy budget. Some makers of gas-fired tankless water heaters claim their products can cut your energy costs up to half over regular storage heaters. So is it time to switch? Probably not. Gas tankless water heaters, which use high-powered burners to quickly heat water as it runs through a heat exchanger, were 22 percent more energy efficient on average than the gas-fired storage-tank models in our tests. That translates into a savings of around $70 to $80 per year, based on 2008 national energy costs. But because they cost much more than storage water heaters, it can take up to 22 years to break even—longer than the 20-year life of many models. Moreover, our online poll of 1,200 readers revealed wide variations in installation costs, energy savings, and satisfaction. With the help of an outside lab, we pitted Takagi and Noritz gas-fired tankless water heaters against three storage water heaters. We didn't test electric tankless heaters because many can't deliver hot water fast enough to replace a conventional water heater if ground­water is cold. Even in areas with warm groundwater, most homeowners would need to upgrade their electrical service to power a whole-house tankless model. Our tests simulated daily use of 76 to 78 gallons of hot water. That's the equivalent of taking three showers, washing one laun­dry load, running the dishwasher once (six cycles), and turning on the faucet nine times, for a total of 19 draws. While that's considered heavy use compared with the standard Department of Energy test, we think it more accurately represents an average family's habits. We also ran more than 45,000 gallons of very hard water through a tanked model and a Rinnai tankless model to simulate about 11 years of regular use. Here's what else we found: Water runs hot and cold Manufacturers of tankless water heaters are fond of touting their products' ability to provide an endless amount of hot water. But inconsistent water temperatures were a common complaint among our poll respondents. When you turn on the faucet, tankless models feed in some cold water to gauge how big a temperature rise is needed. If there's cool water lingering in your pipes, you'll receive a momentary "cold-water sandwich" between the old and new hot water. And a tankless water heater's burner might not ignite when you try to get just a trickle of hot water for, say, shaving. Nor do tankless water heaters deliver hot water instantaneously. It takes time to heat the water to the target temperature, and just like storage water heaters, any cold water in the pipes needs to be pushed out. And tankless models' electric controls mean you'll also lose hot water during a power outage. Up-front costs are high The tankless water heaters we tested cost $800 to $1,150, compared with $300 to $480 for the regular storage-tank types. Tankless models need electrical outlets for their fan and electronics, upgraded gas pipes, and a new ventilation system. That can bring average installation costs to $1,200, compared with $300 for storage-tank models. Tankless units might need more care During our long-term testing, an indicator on the tankless model warned of scale buildup. We paid $334 for special valves and a plumber to flush out the water heater with vinegar. Many industry pros recommend that tankless models be serviced once a year by a qualified technician. Calcium buildup can decrease efficiency, restrict water flow, and damage tankless models. Experts suggest installing a water softener if your water hardness is above 11 grains per gallon. Ignoring this advice can shorten your warranty. Efficient storage models are pricey We also tested the $1,400 Vertex, a high-efficiency storage water heater by A.O. Smith. The manufacturer claims its installation costs are similar to a regular storage model. But its high cost offsets much of the roughly $70 per year the Vertex will save you. Instead, we recommend buying a conventional storage water heater with a 9- or 12-year warranty. In previous tests, we found that those models generally had thicker insulation, bigger burners or larger heating elements, and better corrosion-fighting metal rods called anodes."

2/7/2013 8:47:17 AM

Quote :

"^you probably have old pipes with pressure right on the threshold of triggering it. My install came after replacing every pipe in the house with brand new pex."

Probably, my house is 100 yrs old. The owner is an 87yr old who is sharp, but i doubt she's on top of that^ type of maintenance.

2/8/2013 12:29:10 PM

Very happy with my Rinnai unit. I think it was around $2400 installed, but I got back about $700 in tax credits and $100 in credits from PSNC when I installed it. I've had zero issues with it so far. It has always worked well. It was nice not to have to worry about running out when I had roommates.

Quote :

"The main issue that I have is that it has to draw in cold supply water for a given amount of time to sense the supply temperature so that it knows how much to heat the water to get to the set temperature. Tis results in a longer time between turning the hot water on and actually getting hot water a the outlet."

I think the issue is with the time it takes to heat the water, not the time it takes to sense the water flow and turn the system on. My system takes about 8 seconds to heat the water; so if you have a traditional tank system you can count the seconds it takes for hot water to reach the faucet and add about 8 seconds to that. It's only an annoyance for me when I have to wash my hands during the winter as I tend to waste water by turning on the faucet and doing something else while I wait for the hot water to come. I might put in a point of use heater under the kitchen sink to alleviate that.

[Edited on February 11, 2013 at 12:50 PM. Reason : s]

2/11/2013 12:49:05 PM

wow, your current heater is definitely on borrowed time. very rarely do i see them exceed 10-12 years these days. years ago, it wasn't uncommon to service heaters that were 20-30 or more years old and still going strong. those days are gone unfortunately.

most of the info posted thus far is reasonable. however, there are solutions to most all of the shortcomings/problems that have been listed. if i'm supplying the unit, i install noritz products with rinnai and eternal (stainless is pimp) mixed in occasionally. it's my opinion that noritz is using the best quality internal parts vs. other manufacturers and they have a good warranty/factory support. fwiw, my invoices are usually in the neighborhood of $3000 for a "normal" install including the heater.

have you considered a hybrid heater at all? kind of the best of both worlds (tankless/tanked).

2/20/2013 1:30:21 PM

^ i didn't know there was a such thing, i will have to do some googling on that.


put the water heater replacement on hold until i get this roof leak taken care of.


older homes = FFFFUUUUUUUU

2/20/2013 2:49:21 PM