"L. M. Rappaport" wrote in message
...
On Thu, 08 Dec 2005 08:30:16 -0500, GaryM
wrote (with possible editing):

wrote in
oups.com:

The originally hot water sits in two stories of pipe and cools.
You have to move that much out of the pipes.
You could look at a recirculating system.
You could look at an in-line flow actuated heater.
Both are expensive to install and give better comfort and
performance. TB

Does the furnace need to run more to with a recirculating pump?

Thanks.

Not in this case. The OP said he had a water heater. THAT will run
more with recirculation, but it will cure his problem and slightly
reduce boiler/furnace usage.

We did a substantial addition to our house several years ago. To cure
the same problem, we went to the furthest point on the hot water line
and provided a pipe back to the boiler which also supplies hot water.
The boiler is a Buderus which incorporates a computer output to run a
recirculator. I set it to come on every 30 minutes during the day and
off at night. It is terrific - hot water out of the tap after less
than 3 seconds. If you have multiple water lines, you can add a
return to each and couple them with a tee before going to the recirc
pump. You can adjust by adding a valve to the shortest run, but it
really isn't necessary.

To do this, you need to be able to run a pipe to the end of the hot
water line. This is much easier to do with pex than copper. In a
cold climate (we're in northern NH) there is effectively no
significant increase in our oil bill, since our pipes are insulated
and besides, radiation from the hot water pipe would simply cut down
on boiler heating, more or less.
--

Larry
Email to rapp at lmr dot com


A simpler recirculation system cross connects the hot and cold lines under
the furthest sink. No power, pump or return lines are needed. The downside
is that you will now need to run the cold water just a little (not as much
as you did the hot) to purge the warm water to get cold. Not an issue when
warming up a shower or if you usually drink bottled water. The upside is
these systems are very inexpensive and can be installed in an hour.

Yahoogle on hot water recirculation and you will soon be overwhelmed by
information.

Any recirculation system will cause an increase in hot water heating charges
(gas or electric) but will substantially reduce the waste of water.
Insulating the hot pipes will make a big difference in the efficiency any of
these systems.

While it is not practical to change your pipes, a smaller pipe for the hot
water (1/2" instead of 3/4") would substantially reduce the volume of water
standing in the pipe which needs to be purged before the hot gets to you.