On Feb 15, 9:57*am, "
wrote:
On Feb 15, 12:27*am, DD_BobK wrote:





On Feb 14, 4:25*pm, mcp6453 wrote:

The latest episode of "Ask This Old House" showed Rich Trethewey
installing a Taco D'Mand hot water recirculating pump.

http://goo.gl/lq4aw

As usual, the show doesn't give enough information, so it's hard to say
whether they used the 006 or the 008. In any case, the pumps are about $400.

What do you think about these units? Are there cheaper ones? I was never
in favor of them until I saw that you press a button when you're ready
to use hot water.

My kitchen is a long way from my hot water heater. This device would be
very handy unless it causes diseases or something.

Cheaper but similar

http://www.chilipepperapp.com/cwrcs.htm

the savings on the Taco system presented as

an average of $180.00-225.00 per year on bills for gas type water
heaters
and *$500.00-625.00 per year for electric water heaters.

What parameters was that based on? *Like RBM said,
I think those are just nuts. *First, if you're comparing
using a push button type pump with no pump at all,
the savings in gas is minimal.

With no pump, you have to heat enough incoming cold
water to replace the water that is in the hot water pipe
between the water heater and the point of use. *That's
not a lot of water.
With a pump, you have to heat enough returned water
to replace the water that is in the hot water pipe.
So, the difference is in heating a gallon or two of water
either from about 45F or about 65F. *The other small
savings would be in the cost of the gallon or two of
water that goes down the drain.

My whole gas bill in summer, which is just for
the water heater, *is only $17 or so.

If you're comparing a push button system to one that
already has a pump and keeps it circulating 24/7,
then it would be more substantial, but still, those
numbers are hard to believe.

The biggest drawback to these systems, which I bet
TOH never mentioned, is that unless you install a
seperate return line from the points of use back to
the water heater, the stale, tepid water is going back
into the cold water line. *There it will be available for
anyone who draws a glass of what they think is cold
fresh water. *That person could be at the point-of-use
where the pump is or anywhere else along the path
of the cold water pipe going back to the water heater.
Meaning if you're drawing a pitcher of water to mix
the kids some Koolaide in the kitchen, you could be
in for a surprise. *Before installing one, I'd analyze
what else is on the cold water line and figure out
hot to install a new line if necessary,.





This demand (push button) system will save energy over a continuously
circulating hot water loop.
It will save water compared to dumping cooled water down the drain.

The water savings will only be a few ¢'s per day.

The energy lost in running the loop 24/7 is harder to figure.
Here is a link to another system & the author gives energy waste
numbers

http://www.builditsolar.com/Projects...c/RecircEnergy.......

cheers
Bob- Hide quoted text -

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In addition. no one (including ATOH) ever mentions the cost of running
power for the pump.

On the ATOH episode in question, there was clearly a brand new
receptacle shown inside the vanity where the pump was placed.

Depending on the current electrical situation and homeowner's skill
level, the installation of the receptacle could add significant cost
(percentage wise and payback wise) to the installation.