Discussion:
Plumbing Question - Hot Water Recirculators
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h***@oddkarma.com
2005-08-10 21:52:42 UTC
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Anyone used one of these?

http://www.lowes.com/lowes/lkn?action=productDetail&productId=44944-000070701-ACT303&category=15&lpage=none&bc=c


Are they difficult for an idiot to isntall? The shower upstairs take about
1.5 minutes to get hot. This sounds like it'd save me time and money.
--
\\ \\ Hosun S. Lee // Vorpal Bunny(TM)
\\-\\ http://www.bluebmw.com
( 0-0) "No quip."
{_^_}
Jim Thompson
2005-08-10 22:04:47 UTC
Permalink
Post by h***@oddkarma.com
Anyone used one of these?
http://www.lowes.com/lowes/lkn?action=productDetail&productId=44944-000070701-ACT303&category=15&lpage=none&bc=c
Are they difficult for an idiot to isntall? The shower upstairs take about
1.5 minutes to get hot. This sounds like it'd save me time and money.
The recirculation back thru the COLD water line sounds crazy to me.

I have recirculating hot water, but there's a separate return line
back to the heater for that purpose.

A better solution might be a local under-sink electric hot water
heater that functions until hot water arrives from the main tank...
and less likely to be screwed up by a Beamer owner ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
Paul Wylie
2005-08-10 23:16:25 UTC
Permalink
Post by Jim Thompson
The recirculation back thru the COLD water line sounds crazy to me.
They covered these on _Ask This Old House_ last season. Their plumbing
expert (Richard Trethewy) didn't seem to see any problems using the cold
water as the return, and he talked the homeowner into having an
electrician install an outlet under the sink so he could install the
recirculation pump.
Post by Jim Thompson
I have recirculating hot water, but there's a separate return line
back to the heater for that purpose.
[...]

That's clearly the superior option, as there's no chance of anything
that's bad in one line from crossing over to the other, but the recirc
pumps that use the cold water line apparently meet code just about
everywhere, and I don't recall any discussion of risks associated with
them on the episode where they installed the recirc pump. They're usually
pretty good about covering risks, so that leads me to suspect the risks
were negligible.

--Paul
** Note "removemunged" in email address and remove to reply. **
Jim Thompson
2005-08-11 16:24:43 UTC
Permalink
On Wed, 10 Aug 2005 23:16:25 +0000 (UTC), Paul Wylie
Post by Paul Wylie
Post by Jim Thompson
The recirculation back thru the COLD water line sounds crazy to me.
They covered these on _Ask This Old House_ last season. Their plumbing
expert (Richard Trethewy) didn't seem to see any problems using the cold
water as the return, and he talked the homeowner into having an
electrician install an outlet under the sink so he could install the
recirculation pump.
Post by Jim Thompson
I have recirculating hot water, but there's a separate return line
back to the heater for that purpose.
[...]
That's clearly the superior option, as there's no chance of anything
that's bad in one line from crossing over to the other, but the recirc
pumps that use the cold water line apparently meet code just about
everywhere, and I don't recall any discussion of risks associated with
them on the episode where they installed the recirc pump. They're usually
pretty good about covering risks, so that leads me to suspect the risks
were negligible.
--Paul
** Note "removemunged" in email address and remove to reply. **
My only concern is that this is in a California "ticky-tack"
situation. Plumbing is likely daisy-chained, so someone on the first
floor is likely to get a dose of hot water in the cold line until
pressures equalize.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
Paul Wylie
2005-08-11 23:14:34 UTC
Permalink
Post by Jim Thompson
My only concern is that this is in a California "ticky-tack"
situation. Plumbing is likely daisy-chained, so someone on the first
floor is likely to get a dose of hot water in the cold line until
pressures equalize.
Well, that's probably no different than we deal with here in AZ during the
summer.

--Paul
** Note "removemunged" in email address and remove to reply. **
h***@oddkarma.com
2005-08-12 00:05:16 UTC
Permalink
Post by Jim Thompson
My only concern is that this is in a California "ticky-tack"
situation. Plumbing is likely daisy-chained, so someone on the first
floor is likely to get a dose of hot water in the cold line until
pressures equalize.
I still don't understand how this works. You are supposed to mount it
in the sink furthest away from the water heater. So in my case that's
prolly the master bedroom.

Downstairs in the kitchen would rock though since that already has
a power plug.
--
\\ \\ Hosun S. Lee // Vorpal Bunny(TM)
\\-\\ http://www.bluebmw.com
( 0-0) "No quip."
{_^_}
Jim Thompson
2005-08-12 00:25:16 UTC
Permalink
Post by h***@oddkarma.com
Post by Jim Thompson
My only concern is that this is in a California "ticky-tack"
situation. Plumbing is likely daisy-chained, so someone on the first
floor is likely to get a dose of hot water in the cold line until
pressures equalize.
I still don't understand how this works. You are supposed to mount it
in the sink furthest away from the water heater. So in my case that's
prolly the master bedroom.
Downstairs in the kitchen would rock though since that already has
a power plug.
Draw a picture...

Cold water comes into house, goes into hot water heater and also goes
to all cold water taps.

Hot water comes out of hot water heater and goes to all hot water
taps.

If the furthest hot water tap has a recirc pump, the hot water goes
back down the cold water pipe to where it connects to the heater and
goes back thru the heater.

So, just sitting there, you eventually have hot water in the cold
water pipes.

So the problem is reversed... you now have to wait for cold water ;-)

My house has three pipes, cold, hot and return to heater.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
Jim Thompson
2005-08-12 01:32:08 UTC
Permalink
On Thu, 11 Aug 2005 17:25:16 -0700, Jim Thompson
Post by Jim Thompson
Post by h***@oddkarma.com
Post by Jim Thompson
My only concern is that this is in a California "ticky-tack"
situation. Plumbing is likely daisy-chained, so someone on the first
floor is likely to get a dose of hot water in the cold line until
pressures equalize.
I still don't understand how this works. You are supposed to mount it
in the sink furthest away from the water heater. So in my case that's
prolly the master bedroom.
Downstairs in the kitchen would rock though since that already has
a power plug.
Draw a picture...
Cold water comes into house, goes into hot water heater and also goes
to all cold water taps.
Hot water comes out of hot water heater and goes to all hot water
taps.
If the furthest hot water tap has a recirc pump, the hot water goes
back down the cold water pipe to where it connects to the heater and
goes back thru the heater.
So, just sitting there, you eventually have hot water in the cold
water pipes.
So the problem is reversed... you now have to wait for cold water ;-)
My house has three pipes, cold, hot and return to heater.
...Jim Thompson
Turns out that my description is not quite correct.

The hot water pipe is a *loop*. It leaves the top of the heater and
then goes to each hot water tap in turn, then returns to a pump and
then to the heater, but is connected via a "T" where the drain valve
normally resides, then there's a drain valve on the other side of the
"T".

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
h***@oddkarma.com
2005-08-11 23:54:14 UTC
Permalink
Post by Jim Thompson
The recirculation back thru the COLD water line sounds crazy to me.
To be honest I still don't understand how it works. Sounds like magic
to me.
Post by Jim Thompson
I have recirculating hot water, but there's a separate return line
back to the heater for that purpose.
Is this something that's quick and cheap to retrofit? I'm thinking
no...
Post by Jim Thompson
A better solution might be a local under-sink electric hot water
heater that functions until hot water arrives from the main tank...
and less likely to be screwed up by a Beamer owner ;-)
Bimmer.

I still need to install AC jacks underneath sinks though. Is this
something that will be costly? E.g., more than a couple hundred
dollars?
--
\\ \\ Hosun S. Lee // Vorpal Bunny(TM)
\\-\\ http://www.bluebmw.com
( 0-0) "No quip."
{_^_}
h***@oddkarma.com
2005-08-12 15:24:35 UTC
Permalink
I also saw this:

http://www.keidel.com/mech/pumps-recirculate-r.htm

Sounds like the same concept but now plugged in at the hot water heater.

So any recommendations on other strategies? I'm looking for something
relatively inexpensive (couple hundred) and doens't require renovation.
--
\\ \\ Hosun S. Lee // Vorpal Bunny(TM)
\\-\\ http://www.bluebmw.com
( 0-0) "No quip."
{_^_}
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