Navien Tankless Water Heater Comments and questions

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Dana

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Plumbers don't do software. :)

But the installer is responsible for setting it up to work properly, and there may be firmware rev control issues at Navien(?). It should be resolvable, but from a consumer point of view you shouldn't have to be the one debugging it- it's between the manufacturer & the installer to sort out.
 

Zl700

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Getting it to work properly is more than a internal DIP switch, the remote must be programmed

The orange book describes it
 

Zl700

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"To Dana: You just don't have the right plumber."

Now that's funny!

(welcome new guy)
 

StupFD

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Navien is CRAP!

We spent $4,000 putting in a Navien 210A just over a year ago. Everything was great at first; until the weather turned colder. Once we starting getting temperatures near freezing (many of those days in Ontario, Canada) we starting getting water sandwiching during showers. Usually they would start about 2-3 minutes into the shower and they would cycle about 1 minute of nice hot water and then 1 minute of tepid water. It is tempting to bump up the temperature but 1 minute later, you find yourself getting scorched. We called Navien tech support and even though the unit was under the 1 years parts and labour warranty, they would have me the unskilled home owner dismantling the unit and running tests. It would take 40 minutes just to get through, we would try something and they would tell me to try it for a few days. The problem would remain and I would repeat the same tech calls 3 times. Finally we called the installing company and they came out. Since we only have one shower head in our house and it only presents the problem during showers, they blamed it on a faulty shower cartridge.

Here we are a year later out of labour warranty. Temperatures are starting to cool down and about 2 weeks ago, temperature fluctuation starts again. But Wed. night was the beginning of a new chapter. We get 1 minute of tepid water and 1.5 minutes of no hot water. We have been enjoying cold showers since and we are heading into the weekend with no replacement parts available locally. The unit fires but not at full speed therefore, it can not keep up with water demand. Since there are no codes in the computer, they are going to TRY replacing the water flow sensor and if that fails, then the circuit board. At $120 an hour, the "hit and miss" replacement theory does not sit well with us.

BEWARE...Buy a Rinnai!
 

Jadnashua

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If you want to go tankless (and there are situations where it is a good choice), if you don't start with a good design, proper sizing, and have local, knowledgable techs with parts, you'll probably be sorry. In this case, a tank might have cost $1K to install, and even if it cost $200 more for fuel each year, you'd still have a number of years before you broke even and avoided the hassle, and periodic maintenance, and service outages that are likely.
 

Alex Rock

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Korean technology will be leader soon. Navien is not so expansive as Rinnai, but quality is good. They all have got a patented system, where the pump situated before the heat exchanger. Am i right?
 
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markotah

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Tankless Water Heaters

What never ceases to amaze me is you read they are either good or a waste of money. Like anything else tankless may not always be the best solution. if you have a new install and no chimney or you have chimney or make up air issues and need a power vented OR power direct vent tank model than hands down tankless is a better option! 12yr + warranty or 6 yrs? Unlimited hot water although a a standard flow rate or a tank that you need time to recover.
The consumer report article is somewhat of a joke for not getting any base line to make the comparison.
As far as warranty look for what is actually covered. If it leaks in 10 yrs do you get a new unit or a heat exchanger that could cost more in labor to install? I have seen these units in some areas of very hard water with few issues. The reason is you are only heating the water on average to 120*. for every ten degrees you go up in temp you get 17 times more minerals out of the water. Most tankless units have a valve kit that makes it easy to clean with vinegar or special cleaners. I don't see many of the cleaners sold and a 5 gal bucket and small pump are only $60. If you can tie your shoes you should be able to handle this yourself.
 

Abraham

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Question for the Tankless Enthusiasts and Non Enthusiasts...

I have discussed this with a few local servicemen and I have received varying info.

Some pros have suggested that I go with a unit with a “flow control†feature and others have suggested that I go with a unit with a “thermostatic†feature. And I seem to be receiving varying info regarding what each feature provides.

So I did my homework and referenced both features and fortunately I’ve been able to get what I believe is conclusive info regarding what exactly the “thermostatic†feature provides, (modulates the output gas depending on the varying incoming water temperature in order to ensure an accurate hot water temperature).

But I for the life of me cannot seem to get any info regarding what exactly a “flow control†feature is… and the interesting thing is seemingly every manufacture claims that their units have “flow controlâ€â€¦

So in short my question is what exactly is meant when these manufacturers label their units “flow control†and are my findings correct with respect to the claim of a “themostatic†feature?
 

Dana

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As I understand it, when the burner modulation has already hit the max rate, flow control restricts the flow to maintain the output temp at or near the thermostatic setopoint. Without flow control the output temp might otherwise drop at high-flow, high delta-T. In practical terms that's not very important for gas-fired units in warm-water states like GA, but if you're trying to fill a tub in MN in January with 35F incoming water, maintaining a high enough output temp without flow control might be more critical even with a 199kbtu burner behind it.

In GA that would almost never be necessary with any "whole house" gas-fired unit, but would be with an electric tankless since their ratings are so much lower. A 24kw electric tankless is roughly equivalent to a (fairly light-duty) 100KBTU/hr gas tankless, and even in GA the ol' lady would outright kill ya if you decide to start the washer while she was in the shower in January with a 12 or 15kw unit, without flow control (and a functioning anti-scald valve.) But a 36kw unit would probably support two shower flows in GA without needing to throttle back on flow to keep temps up.
 

Abraham

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Thanks much Dana, but I'm afraid uch of that flew over my confused head...

If I understand correctly, the "flow control" feature that many of these units tote is essentially a flow restrictor? And if thats the case why would the flow be restricted? Is it b/c the unit wishes to guard against the possibility of another tap or two being drawn at the same time? And why would this be designed to occur only when the "burner modulation" hits the max?
 

Jadnashua

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Move you hand through a flame...move it faster, things are cooler...slow it down, they get hotter. Now, change that to a blowtorch, if you go through it fast enough, you won't get burned. Now, replace your hand with water going through the burner. Two ways to get the water to a fixed temp...how fast you move it by the burner, or how hot the burner is. If the water is cold coming in, the burner might not be able to supply enough heat if you are trying to run that water by fast (i.e., using lots of water). So, having both the ability to adjust the burner and slow it down, if trying to use lots, are two methods that will allow the thing to output a fixed temperature.
 

Abraham

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Thanks for the additional clarification Jadnashua... So essentially this "flow control" feature that these marketers promote is merely a mechanism to guarentee that the hot water temp doesnt suddenly drop due to a sudden increase in demand or colder incoming water temps (hence the reference to Delta T that Dana made earlier).

Yea Dana you almost lost me with that one (Delta T) but then I used the magical Google tool...
 

Dana

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Sorry- I live in the nerd-world, where expressions like "delta-T" are practically small-talk. (Note to self: define your terms- always.)
 

G WASH

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Where are you going to use the unit? Will there be a water softner and filter's preping the incoming water supply. See my perspective is different than many here. I own carwashes and I make a living off of the end result...HOT water. Over the year's I've tryed nearly every form of hot water production. And I know thru discussion with other owner's of washes and related industries "What has worked and what sounded like it should work". It's obvious that the condensing unit's are much higher in eff. The deal as I see it is as alway's value over time and cost when it's all said and done. The price on the Navien 240's is right at 2,000$ unit only. Track record...a realy short one. If it's for a large home or small business of mine I would go with what I KNOW... The Takagi TK3 Pro is the staring point of thier commercial line. I have seem their prices dropping over the last 2 year's. I picked up a TK3 for 725$ and the higher tech/more durable burner TK3 pro for 900$ Most good Carwashes use commercial grade softner and filter's that are over kill so as to make the process of producing spot-free rinse water easier and less costly in the end...As a result this make an already highly reliable TLHWH last a long,long time. All the wash owner's I've asked said they had never had the front panel's off their TK2,3's and up. I personally have had mine for 7 year's plus...no repair's The other wash owner's tell the same story. Takagi commercial line is a work horse at a busy carwash...should last 20 year's in a home and at those prices I think i'll wait to see if the Kia..of sorry Navien from Korea can walk the walk In a heavy use areana. The 1100$ price difference will buy a lot of natural Gas...Sorry I hate spell checking so you get my drift
 

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Hola... like others, google search brings up this thread near the top, so kinda resurrecting. Abraham can probably tell you more about code (I live in the Atlanta area too), but I went with Navien NR-210A because of the costs and research.

1) house was built in 1993, fist owner. It still has the original A.O. Smith 40gal HWH tank. I've NEVER serviced it and barely even glance at it; however, 17yrs old got me to do some research. First, my bet is that the bottom will dump soon. It's isolated, so I don't believe much damage will happen. Second, it's terribly inefficient by todays standards. I run out of hot water quicker and it takes awhile to get any back. Since it was built in 1993, the codes were different. For me to install a new tank HWH would require the company to install a square cement wall around the unit and deepen the ditch (it's in a "half" crawl space with 6' height). The existing unit is 48" and newer units are taller. BLUF: to replace with a .7EF HWH, 12yr warranty, do the install with construction will cost me about 3k and no 30% Fed Credit.

2) for 3.3k, I get a new Navien NR-210A (bells/whistles), .98EF and installation of circulation T's at the long runs on external circulation, 15/5yrs warranty ... and the 30% Fed Credit. To me it was no brainer. More efficiency, less cost overall after credit.

My math:
Standard tank: 3000.00
Tax Credit: 0.00
TOTAL: 3000.00

Tankless: 3300.00
Tax Credit: 990.00
TOTAL: 2310.00

Delta: 690.00 savings going tankless, + reduced gas costs.

Anyone see anything wrong with my math?
 

Terry

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If making all of those changes will run $3,000 for a tank type heater, then you might as well go tankless.
If the tank had been in a garage, then replacement with a new tank and expansion tank would have been less the $1200
Depending on the market, maybe even less then that.
 

Dana

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It's usually hard to make an economic argument for going tankless if it's based on fuel savings alone. But this one sounds like a no-brainer, even if you add in some service charges for mainentance over the next decade or so. And just thing, you'll be able to waste as much hot water as effieciently as you like with an EF of 0.98! :) (Have any long-showering teenagers in the house?)
 

ImpliedConsent

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If making all of those changes will run $3,000 for a tank type heater, then you might as well go tankless.
If the tank had been in a garage, then replacement with a new tank and expansion tank would have been less the $1200
Depending on the market, maybe even less then that.

Well, I certainly didn't think that I'd get a response from "the man", but there it is. Believe me, I'm envious of seeing HWH's in the garage, but mine is in our basement's 1/2 crawl space. It's convenient on one hand, I never see it; however in times like this, it's a burden. I've had 3 companies come out and they won't touch it without the modifications. My 3k quote was the low quote (I won't even suggest what the others were). From all the research I did, the Nevien consistently hit the top of the charts as it relates to EF and warranty (my 2 criteria). I provided each company with my research. I got responses from my research: from dumbfounded - never heard of companies like Navian or Noritz or Paloma ... to stunned happy surprise that a consumer did research. Needless to say, the Navien won out. My research was done not on company market fluff, but the governments Energy Star program. As of right now, there are ZERO tank HWH's that qualify for the credit.
 

ImpliedConsent

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It's usually hard to make an economic argument for going tankless if it's based on fuel savings alone. But this one sounds like a no-brainer, even if you add in some service charges for mainentance over the next decade or so. And just thing, you'll be able to waste as much hot water as effieciently as you like with an EF of 0.98! :) (Have any long-showering teenagers in the house?)

OMG: 13yr old who thinks water is unlimited resource for her showers is an understatement. She is effectively training my 7yrs old daughter those same habits. I would say that my wife is the master of giving me cold showers, but I think she lurks here. I'm in the military, so taking a hot shower is a luxury anyway, so I'm used to it. :D
 

ImpliedConsent

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One more thing (before I become a pain in the @$$): just found out that I also qualify for my states Energy rebate program, which is another 199.00. Total savings: 889.00
 
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