A year+ has passed since our last thread attempted to gather information on this type of water heater. I'm hoping to hear about reliability, installation, cost, and vendor recommendations. While competing alternatives deserve discussion, please consider separate threads for them. My local situation unfortunately makes solar thermal a difficult and expensive proposition to install; heat exchangers are a poor fit for my mostly heating climate and unconditioned garage install; and demand electric sourced from coal is not what I want. Anyway, to start off with generalities, I'll answer why I want this heating method if I can find a TCO cost within 100% of my electric: 1. Less pollution than electric (remember I live in coal country) 2. Side venting. I have a gas line, but no vertical venting
Never bought one (this one - regular nat gas - was already in the house). In NJ lacking gas supply we installed oil hot water heater. Saved us tons of money because elec rates were sky high years ago. In any case, you cannot beat an oil hot water heater for heating water.
Sage, is that a condensing tankless? I looked at them over the past 5 months, and I can't justify the cost plus install right now. The one I found that I liked best, was around $1200 for the unit, and roughly that cost for installation. You could get a gas tank for a lot cheaper if you wanted to get away from electric. I likes Navien ones, mostly because they have no minimum flow rate required. Here's a link to purchase the unit: Navien NR-180A-LP Liquid Propane Condensing Tankless Water Heater with Pump and Buffer Tank Manufacturers site: -:- Navien America -:- Feel free to shoot me a PM if you have any questions about my research. I tend to lose track of threads on here. WJTRACY - Oil is roughly 4.30/gal here, and NG and LP are actually a bit cheaper in this area, except LP if you're just using it for water heating (LP is all about usage for cost here). I'm looking at an oil to propane conversion for my heater and that opens up the option for the tankless condensing water heater, gas stove, gas clothes dryer, etc, etc. down the line. It's also cleaner vs oil and requires less maintenance WRT cleanings. That said, I do love the warmth of the oil furnace, but the cost to run it is unbearable.
Here's a recent thread on MNL covering the same topic. My Nissan Leaf Forum - Gas Tankless water heaters. Worth it? Apparently there are high efficiency gas tankless water heaters efficient enough to be condensing. IMO, I would look at those if you have enough gas to run them. Really tough to beat one of those in terms of efficiency.
Takagi USA - The tankless water heater pioneers. Experience "Endless Hot Water" The only name I need to know. K3-Pro, K4 or D2.
I have a Rinnai Tankless water heater, which I love. I am not clear if it is condensing. http://www.amazon.com/dp/product/B0058DQLPW?tag=priuschatcom-20 to remodeling I needed to reclaim the space where the existing unit was, I was able to hide the Rinnai in my walls so that only 2 inches stuck out into the room.
...yeah I know oil costs so much more now. I wonder why in the Northeast there is not more push to get nat gas lines out to folks stuck on oil heat? But we loved our oil hot water so much we kept it when we finally got the nat gas line for heating. Not sure if I would have swiched by now. Hot water did not use much oil. But you need the oil tank which we already had.
I wish they would run the NG line to me. I checked andit would be $90k to get them to my neighborhood. LP, if you own the tank(s) can be under $2.50/gal around here. Most people dont own the tank though, and that puts it around $3-3.25 Oil hot water has an amazing recovery time. I think I read like 45 gal an hour. I want to get rid of my elec tank heater, but cost doesnt make sense because its only 6 yrs old.
we got Takagi tankless natural gas heater 7 years ago and could not be happier. They are pretty efficient, the model we have is rated 0.86 efficiency, so the carbon footprint is pretty small. Takagi can be mounted outside and with the side venting, take a look: Takagi Venting Pipe and Accessories from FaucetDirect.com
I have used nearly all brands of demand water heaters. My curren favorite is the Rinnai 96% units. They can also be coupled to a Rinnai air handler to provide space heat all in one integrated unit. Great units. I also like the Takagis, but am not fond of Bosches. Icarus
My understanding is that condensing heaters have two advantages: 1. higher combustion efficiency; and as a result of 1, low temperature exhaust gases amenable to side venting. Regular non condensing heater can also be side vented, but I have gained an impression that the side venting introduces reliability problems, and expensive ducting must be used to contain the hotter exhaust. Tank vs tankless is actually a separate consideration. The difference in price between them pales against the cost of installation when a fatter pipe is needed to feed the tankless variety.
i have a 17 year old standard ruud 40 gal. gas hwh with power side vent and 4" metal side ducting, no issues so far. probably not that efficient tho.
I installed a 90-95% efficient "condensing" gas heater in my house in NJ and inherited one here in VA also. These side-vent warm moist air via PVC tubing. Those heaters have both been reliable. My inherited gas water heater is a Ruud power vent, not too efficient - probably not a condensing unit - but the power vent is a blower on top that blows the exhaust through a PVC side vent.
We just switched to gas from oil. The boiler is a Pure Fire condensing. The water heater heater is a Brady White. Not sure if it's condensing or just a power vent. Both types will have a blower to vent the exhaust. The condensing needs it because the exhaust could cool and lose velocity to the point of possibly preventing proper venting.
Rinnai 96% condensing demand water heater! Simple direct vent, no stand by loses. I use on coupled to an air handler for space heat as well. Great units. Icarus
