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maxodyne

wrote:
On Dec 31, 2:00�pm, maxodyne wrote:

KLS wrote:

Well, I asked the friend who I thought had bought tankless to replace
his water heater, and here's what he said:

===
We ended up with a bit larger traditional hot water heater, with some
energy saving features. It's been working out well, as has our new
high-efficiency furnace and AC unit. A tankless hot water system was
not recommended for our home. Two independent assessments confirmed
it. One concern was that the water from the street is too cold. Also,
tankless systems are so expensive that to buy, install and maintain,
that any savings and convenience evaporate quickly.
===

And on top of the recent post from maxodyne alerting us to Bosch's
warning not to use solar-heated water with their tankless, I'm leaning
toward staying with the tanker and using the solar water heating, but
time and experience will tell.

KLS -- don't give up yet! The tankless water heaters go so well with a
solar hot water system -- assuming you'll be storing solar heated water
in a large, insulated tank, which is a common method. From there, the
pre-heated water gets circulated to your tankless which will remain off
if the water is pre-heated enough. No need for standby tanker loss when
you have oodles of already hot water stored elsewhere.

Just because the Bosch heater that I ended up with was not designed for
solar doesn't necessarily mean that they are all that way. I think we
have some expert appliance people in on this tankless vs. tanker thread;
perhaps one of them can tell us which tankless heaters will work in a
solar pre-heat situation.

I'd like to address two issues in your friend's statement:

* "One concern was that the water from the street is too cold"

Then that water will be cold regardless of how it is heated. I can't say
about other tankless water heaters, but Bosch makes higher-BTU models
for very cold inlet water applications. I would think that Takagi also
does, as it can get quite cold over there in Japan ;^)

* "... tankless systems are so expensive that to buy, install and
maintain, that any savings and convenience evaporate quickly."

Hmm, I wonder why anyone would buy such an appliance then? Certainly,
they are expensive. And certainly, people are buying them anyway. I'll
testify as to the expense -- OUCH! I *could* have just slipped in a
replcement tanker and have been done with it, for around $500. For those
who may have missed my "tank-type vs. tankless cost analysis" in a
previous post, I have included it below.

Preamble: I was not motivated to go tankless on cost alone (initially
high until payback time (8 years), then cheaper). I was willing to pay
more money up front in order to consume less natural gas in the long term.

================================================ ====

Here are some facts about my heater replacement cost: A new Whirlpool
50-gallon tanker was $430 at Lowe's, and my Bosch was $998 at the same
Lowe's (a popular U.S. homeowner's supply store). The Bosch also
qualifies for a $300 federal income tax credit (expires 31-DEC-2007).
Doing the math, I am now losing $268 for choosing to go tankless vs. tanker.

Add to that loss about $75 for 3/4 copper pipe & fittings, $35 for a new
3/4" gas flex line (gotta have a large one for high BTU tankless
installations; fortunately for me the steel line is 3/4" all the way out
to the meter), and 8 feet of new stainless 3-inch flue (can't use the
original tanker's galvanized due to the tankless' almost continuous
condensation in the flue) which came to $325; all of which were needed
to do this one-time tank-to-tankless conversion and I'm in the hole
about $700 (Next time, if there is a next time, the cost will
*theoretically* be just for the tankless heater alone). At the current
price of natural gas, payback time for choosing tankless vs. tanker will
take approximately ($700 tankless vs. tanker added expense divided by
$86/year savings) 8.1 years. I'm OK with that.

But IMHO there is more than just money involved here. I chose to go
tankless because it uses less energy in the long run -- a responsible
thing to do in this day and age, I believe -- and I have no regrets in
that regard. I am learning to adjust my lifestyle to compensate for my
new tankless heater's idiosyncracies, as previously mentioned. Plus,
there is the endless hot water advantage -- upon which someone else in
this thread sagely commented can also lead to "endless hot shower
advantage" in some circumstances ;^)- Hide quoted text -

- Show quoted text -

How EXACTLY did you calculate your water heater cost savings?

Please refer to the details in my previous post. If you find errors, you
won't bruise my ego if you let me know what those mistakes are. There is
only one variable, and that is the price of gas, which in my case is
$0.915 per therm at the moment. My apologies for stating "at the current
price of natural gas"; I should have given the actual cost. However, the
price of gas this week or next month is irrelevant for the purposes of
*comparing* tank vs. tankless heaters (the thread subject & my current
ambition), as are weather, incoming water temp, etc. I am comparing one
type of gas water heater, a storage tank type, to another type of gas
water heater, a tankless type.

As to my estimated payback time of 8.1 years, that is based on the
current 91.5 cent per therm price. And my estimate is probably off by
10% one way or the other. As the price of natural gas goes up, which it
probably will, the payback time will shrink accordingly because the
tankless will consume fewer therms over a given time period than a
tank-type heater.

Regarding your comment on the downside of endless hot water, you raise a
valid point. Another poster previously did as well. So far, that does
not appear to be an issue in this household, which consists of two
teenage sons and me. In my case, sewer charges are flat-rated i.e. are
not tied to water usage. So the only lurking "hidden costs" for this
endless hot water -- and the gas to heat it -- would be minimal to
unmeasureable, I think.

After this morning's flurry of hot shower-takings, my older son took off
to spend new year's eve day with friends. Only two of us remain. The
current time is 3:30 PM PST, and no hot water has been used since all
those showers. I wonder how many times the old tanker would have cycled
on and off during that time? Wait! A lady friend is coming over later
this afternoon, perhaps she'll take an "endless" shower. Perhaps I'll
even encourage her ;^)

gas varys in price constantly, incoming water temp variations
depending on how cold weather is, amount of hot water used, presumably
with endless hot water more water sewer and gas will be used to heat
that water.

with so many variables how did you arrive at a exact figure?