Installation of Tankless Water Heater: Candid opinions needed

Looking for experienced, but "off the boilerplate" advice to help decide if its practical to move to a gas tankless water heater.

We're in the process of finishing the basement of our 80 YO townhouse in NYC. Our family's water use patterns seem well-suited to tankless capacity. I'm aware of the costs long-term being almost a wash between a well-insulated traditional storage unit and a tankless unit. The attraction for us is in a small-footprint urban basement is to free up some precious floor space by hanging a heater on the wall that's a sixth of the size of our current tank.

I thought I had a slam dunk easy installation scenario as there was an unused, clear dedicated chimney flue available- it was originally used for the squat coal-burning water heater that was installed there in 1926 and has long since been removed. That is until I started reading all the caveats in the manual regarding venting Category III appliances.

The chimney where this flue resides is massive- I share it with my neighbor as our townhouses are attached- it has six throaty (9-10") flues, 3 for each of us- It's approximately 3 1/2 ' across and 7' deep. From the basement to the top of the coping this runs a little over 50'. All but the last 6 feet of this chimney runs is indoors - it basically doesnt get chilled in the winter as do most exterior exposed chimneys.

So here's the conundrum: I was thinking that I run a short length of 4" Category III pipe from the heater into the flue and terminate with an elbow that aims directly up the flue- cement in where the stainless pipe enters the old 7' flue opening into the tankless heater mounted directly below. Yet all the literature warns that high-efficiency exhaust is cooler and more easily condenses on cool masonry, washing it with an acidic mist that will rot away the chimney from the inside, eventually leaking fumes into the house. According to the official line, a stainless category III liner must be installed the entire length of the chimney and sealed at the top. So much for slam-dunk easy.

I'm not so sure my original venting idea was so bad, given that this appliance will be used really quite intermittently, that it's venting up a pretty wide bore that's largely at room temperature. Very much off the record, the mfr's rep conceded that given my house's particulars, that it could work fine.

So, I'm throwing this installation idea out for opinions, off the record if you like, if the idea is technically unsound. I'm not married to the idea of a tankless installation- it would be a nice-to-do if it were easy enough to install. (BTW, drilling through the wall for an alternative exhaust point won't work- the townhouse has windows too close to any likely exit point, and the house is within our Landmarks district and a protruding stainless pipe will not pass muster.)

Thanx in advance for any thoughts...

There have been several heated discussions here in the last few months re tankless systems. Use the search function above and read them, then decide. Assuming you pull a permit, they will not look kindly on not following the manufacter's instructions re the flue. Do you know the temperature of the incoming water at the end of winter? Mine is about 34 degrees. Most systems raise the incoming water about 70 degrees. Throw in any length of pipe and you get lukewarm hot water. The beauty of a tankless system is you can install them in a closet closer to the point of use. Good luck.

My comments on tankless water heaters:

I have a Bosch 125B

It works okay. Yes, my gas bill is cheaper because it's not heating the water constantly. I only have two complaints...

1) Flow Rate is about half in the winter because the water temp is cooler. It takes more time to heat it up. This isn't noticeable in the shower though, but you can see it in the washing machine, or anything that doesn't have a restrictor.

2) It's not constant. If you turn off the hot water, and then turn it back on, you will get a few moments of cold water through the pipe. To solve this, it was suggested I used a buffer tank after the Bosch. Like a small 1-5 gallon water heater.

Stay away from Bosch, but to get anything decent you're going to pay a chunk of change. I paid about twice the cost of a normal water heater, and while I don't like it, I don't hate it either. I have endless hot water.

Now mine is vented into my masonry chimney. I'm not sure if it is lined or not inside the flu. My furnace vents into it as well, so the plumber tapped that vent.

You can always do it and then get the chnimney inspected and/or cleaned in a few years and see how its holding up. Can always install that flue liner later if you need it.

Jason

tankless water heaters are JUNK

It simply AMAZES ME that even the people that actually
own these units really have a LOVE-HATE relationship with them....
As the fellow before me said,
I dont hate the Bosch , but I dont Love it either...

In a sense , once you have bought one you are sort of
Married to it hopeing that everything works out ok and
you dont have to Divorce it someday..thats expensive
So.......you simply put up with it (like with your wife)

no body wants to admit that they would have been happier
if they would have just stayed away from the damn things...
(the tankless water heaters, that is)



So Stay away from the tankless water heaters.....

comon sense reasons for this are many...

1. they cost about three times as much as a normal unit
once you add in the extras to get one installed properly..
YOU WILL NEVER , EVER RECOUP THE COSTS ,
maybe in 15 -20years.. and it certanly wont last that long.


2. usually the heat coil needs to be "cleaned " with vinegar
every year or so to keep it efficient....
now that sounds like funn, fun fun. and you got to add this expence
into the equation too...


3. In New York city you will most likely find a repairman in a
fairly quick time period for the unit if it were ever to break
down.
It might only take a few days to get him to come
out and maybe only another week or two to order or find the parts.

Cold showers for 10 days or so, while waiting
for for special repair parts for that special tankless
water heater is not much for your wife to endure....right???

4 The repair man better know what he is doing
to repair the unit properly,
or he might burn down your pretty townhouse..

and dont forget the BILL for repairs.....
it will probably be more than what another
normal heater will cost........

ALSO REMEMBER---
YOU ARE LITERALLY GOING TO BE AT THE MERCY
OF THE ONLY REPIAR MAN IN 50- 100 miles.....thats not good.


anyone can repair a tank type heater today....
but very few want to mess with
a Bosch, or takagi ect...

I wont touch one
and I dont want to learn how to
to repair one for the first time on your home either......
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read this link that Brad ford white put out a while back about the two options...

they sell both syltes and even they are leaning towards the normal tank type unit.. you can clearly see that even though they offer both, they
cannot give an accurate figure on what , if anything you will actually save
with the tankless...

in fact they almost claim the opposite because their are so many variables that cant be calculated with the tankless ----like future repairs ect....
and how long the unit has to work properly before you will break even
over a common tank type heater.....




http://www.pmengineer.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2732,141364,00.html

"tankless heaters are JUNK."
--master plumber mark



Kenisdad,
Well, you asked for candid...

I would love my Bosch if it was installed in a shop/garage, etc. Anything that didn't have a high demand of hot water, and wasn't used all that often.

For the $500 I paid for the unit, I wish I would have bought a standard water heater. I had even contemplated switching it out for one, but realized it would cost me another $200 and well, I don't hate it that much, but I won't buy another one.

Mark hit the nail on the head.

I too was thinking about getting a tankless unit. Latest technology I thought... That is UNTIL Master Plumber Mark smacked my head. Now I realize that my 50 gal unit is fine, and I know in ten years that I can just go to home depot and pick up another unit and install it in 2 hours if needed.

SteveW said:

"tankless heaters are JUNK."
--master plumber mark



Kenisdad,
Well, you asked for candid...

Click to expand...

Brianj, you can vent your 125 B into an existing chimney as it uses B vent. I think the original poster must be talking about the bigger models that use the dedicated stainless steel vent that is very dear in price.

I am going to come down on the I love it side of this argument. I have a 125 NX with the auto pilot and it works great............does it operate differently than a tank type......definetly. It just takes getting used to. Now how long it will last and how it stands up re: repairs and such is yet to be determined.

Never mind cost recovery etc...........how about saving some of our natural resources for our grand children! That has to be factored in as well.

Different Tankless Coil

There are a lot of residential oil-fired hydronic boilers in New England that use tankless coils to heat water at 3 to 5 gallons per minute. The problem is that you must keep the boiler on in the summer which is a great waste of now-expensive heating oil.

I put in a 40 gallon electric tank heater with the inlet supplied through the tankless coil of my hydronic boiler. It is valved so I can isolate it but I never do that.

In the winter when the furnace is running, the furnace heats the water that is that is supplying the hot water heater and the temperature is higher than the electric settings so the electric elements are never on. When I turn off the furnace in the spring, the electric takes over.

My electricity cost in the summer is about half the cost of the oil that I was using to keep the boiler hot, and in the winter my water is heated with oil at about half the cost of heating it with electricity.

it takes some getting used to

that says it all.....

it takes some getting used to....


basically you got to get used to listening to
your wife bitching about how crummey the
new water heater is...
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as far as the future generations......
our childrens childrens ect....

if you arent saveing anyhing, whats the difference...

why dont you just take cold showers and think
about all the energy you are saveing for them

if it makes you feel better??

I would rather take a hot shower and ride
a motor scooter to work like the chineese do...

cause someday thats probably what our children -
childrens will have to get used to...

with democracy for everybody ,

like we have been pushing on the world for years,

their simply isnt going to be enough oil to fill everybodys needs

Although I do respect the expierence and opinons of other plumbers on this site,,,Their's is NOT the only opinon .

I've installed several of the Rinnai tankless heaters on additions / pop tops and have had great feedback from customers ! Couple of these are several years old and doing well . Might be the wave of the future, might not be . But not all new things to us are JUNK . Remember the "Cast Iron versus PVC" debate years ago ? LOTS of plumbers said ," It's junk,it'll break easy, it'll NEVER stand up." OOPS,,,missed that boat didn't they.

Also, tankless have been used in Europe for years. Not just a few ,,,,lots of years !

If you are too concerned then go conventional, they work great too.It's your decesion.

While everyone has given their opinion on the tankless WH can anyone address his concerns about his venting situation should he decide to go with the tankless. My NSHO is to comply with the Mfgr. venting requirements and whatever local code requires AND see if it will work with the local covenants. If they don't fit the covenants you could apply for a waver, they might give you one. As far as what the rep told you I would forget it.

CAL---How many have you had to repair???

I hate to sound negative all time,

and am sorry about my crummey tone...


But how many of these little jewelles have you had
to trouble shoot and repair for your customers???



Thats where I am more concerned than the actual
installation... Its backing up the product and serviceing
it in a competent and quick manner,,,

That is the true --- MOMENT OF TRUTH,---

you know you just
installed it for your good customer lets say 3 years ago
for lets say $1500.---2000.....and now they got cold water
over X-mas holidays.with company comming ect--ect
and you need parts asap......

and they are giveing you evil looks...

What do you do???,,,,,,,What do you do????

now they arent going to want
YOU to use THEM for gunnie pigs
trying to figure out how to "jump start" or "rig up" this unit
to get them by till parts show up......


so ---have you actually had to get "down and dirty"
with one yet on a Satruday afternoon
or is this still looming ever so brightly in your future????


I just feel that some things that work great in France
should stay in France, thats all....
.

Electric Tankless

There are a lot of tankless heaters in Europe but all that I have seen are electric. You get a little dribble of nearly hot water out of them.
The cost of energy in Europe is so great that they are willing to tolerate the discomfort and inconvenience of limited hot water, dim lights, cold bedrooms, and small cars.

To heat ONE gallon per minute of water by 60 degrees you need 38 Amps on a 230 Volt circuit. You probably need to run a 50 Amp circuit for that. And one gallon per minute is a pretty weak shower. I stayed at a number of Bed and Breakfast establishments in Ireland in May and they were allowed only one of the tankless heaters in each facility because of demand on the system.

Thanks Bob NH

thank you for the information....

sounds like you might be better off
and more comfortable takeing a sponge
bath than endureing something like you went through...


another problem with the electrics is the coil
has a tendency to clog up and lime up over a short while

and
then someone has to run vinegar through it to get the
efficinecy rate back up to its original installed state and
also the flow gets restricted

probably keeps those plumbers in Ireland busy

Thanks 4 the replies- now the next question....

Thanks all who have replied- rough & tumble works for me fine. Great grist for doing more intelligent due diligence...

As I originally posted, I was not married to the tankless idea, just the concept of freeing up the basement real estate appealed to me. So it looks like I'm headed for a storage type heater.

Maybe I've been looking in all the wrong places, but I can't seem to locate any authoritive info (brand comparison or otherwise) on tank heaters. For instance:

- Do models with 2 anodes last longer?
- Where and why are power vented units used? Can they be vented up a chimney flue?
- Are units with electronic vs. continuous pilots troublesome/ less safe?
- Is it safe to assume that the high-efficiency, 2" foam insulated units are all basically the same, energy-consumption wise- and just shop for the best warranty?
- Are some Mfr's that stand head & shoulders over others (obviously a very subjective opinion)


Thanks again for the lively comments.

I just typed out a lengthy response on this thread, been having a problem on this website only when I spend a substantial amount of time on replying to a thread. I go to click on the "submit reply" button and the screen freezes. I planned ahead and right clicked, then highlighted my response, clicked copy and then clicked the submit reply button. As always, the screen froze and I had to close out the screen. Opened it back up, went back to this thread, hit reply and when I right clicked this time, there was no way for me to paste. It wasn't highlighted this time. I am sure Vbulletin can address this problem through technical support. But I'll be damned if I am going to type everything I wrote again. Mark makes valid points and brianj makes a crucial point that keeps tanks in homes for years to come.

As far as repair goes,,,,,,the WONDERFUL thing about Rinnai is that it is dummy proof. It comes with a remote pad ( placed 3-10') from it that is a temp control AND a trouble shooter guide.If there is a problem ,a code flashes on the screen . Take the handy book from it's pouch ,match the code and get to fixin' . YES my supplier has replacement parts . And before you ask,,,, NO, I DON'T CARRY ALL OF THEM ON MY TRUCK ! If we carried everything , we'd all drive 18 wheelers .

Have you na-sayers even TRIED one of these ? Gone to a class on them ? Had any feed back other then some article in a plumbing magazine or web site ?

I'm done beating my head against a wall with this thread .

Dont beat your head against a wall

I beat my head against a wall every day
worrying about what my retatred employees are up to...
and what excuse thay re going to tell me for not being
at work today........

dont get all frustrated with me cause I dont want to
learn something. new ...

I dont want a BlackBerry phone either......everyone tells me their
great and all I got to do is read all the instructiions and then
learn everything all over...........again......
I just want to keep things simple and easy going as poissible....

And I honestly dont want to have to take a class from some sales rep
on how to repair one of these little beauties....

Remember, they never break down on tuesday,
only on Friday nights at x-mas.



Good for you .that you are willing to learn something new and innovative
....

I respect a fellow that has the patience to
get out the handbook and actually read the instructions first...

I would probably just hit it with a hammer...LOL

you are in the top 1 percentile of all plumbers

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Now Whirlpool electric water heaters also has a remote control
pad on top of thier electric water heaters you can buy at LOWES...

its got pretty lights that blink green, red, blue and yellow on it too!!

it tells you when either the upper or lower element is burnt
out or whatever else goes wrong with the unit.....REAL FANCY

you get out the instruction book and it tells you whats wrong....


the trouble is when one of those elements burnout it
has a tendency to send a power surge through that controll
and then the controll is shot......it sends out bad readings...LOL.

You will not find one of those new controlls
at LOWES when you need one....they dont carry them...

I wont put one of these in either,

keep things simple.........thats my motto...

and I get home in time for supper tonight