You should be able to set it up with a manual timer that you set a few minutes before you want to use hot water. (i.e. twist the dial and the pump runs for up to an hour)

Where would that manual timer be located? Our water heater is in the basement. Would you use one in the bath and one at the kitchen sink?

Thanks.

You could have one installed in the farthest bathroom with a remote to turn it on. It turns off when hot water is sensed at the pump. Chillepepper is one brand ( http://www.chilipepperapp.com/tcs.htm) I have the pump installed at the heater. It has a timer but I have it turned on all the time. But I have it plugged into a X10 module. ( http://www.x10.com/automation/index.html -- but there are other X10 suppliers) I have a X10 controller in the master bath and in the kitchen that turn the pump on and off when the appropriate button is pushed. The down side is that one needs to know how long it takes to get hot water to the various locations. In my case it takes 1 minute for the master bath, 5 minutes for the kitchen and 8 minutes for the back bath.

Install a timer that allows multiple cycles per day.

A simple $5 dollar timer for lights and a 115 V coil relay to control the pump.

The whole thing should be less than $30 in parts.

You can have the circulator in in 30 minute chunks throughout the day.

Minute ny minute control is not needed.

The Chilipepper type units dump cooled hot water into the cold line.
Possibly acceptable for a bathroom, not a good idea for a kitchen.
Hot water carries higher levels of contaminates leached from the house system.

Thanks for the added suggestions!

You could wire the bathroom one into the light switch. Turn on the light, turn on the pump. You could put a switch on the wall above the kitchen sink. Turn on the switch, turn on the pump.

I assume the pump you are chosing has a thermostat that shuts off the pump when the water is hot.

The same but different...

I've had one of these installed in my house for years http://lainginc.itt.com/pages/autocirc.htm

When I installed it I monitored the electric bill closely for a year and could not detect any rise in the electric use. In the scheme of an entire house that pump, with temp sensor, uses so little electricity it really costs pennies to run.

You can read up on that Autocirc on this forum by clicking here

I don't understand why no-one ever mentioned taco product called D'mand system. Which is a circulating pump that is operated by a push button which is either wireless or hard wired, or a motion detector. That would be the best system out there, just a little pricey but the best out there for new construction home.

As long as you do not drink from the faucet the systems that put the cooled hot water back into the cold line might be acceptable.

Once water has been heated it can dissolve more undesirable things (like metal from the pipes and solder joints) and is not recommended for consumption.

Real recirculating systems do not have this issue since they return cooled water to the water heater to be reheated.

The penalty they have is the heat loss form the piping in both directions.
Pipe insulation is mandatory to reduce energy loss.
The pumps themselves are a very small load, and can be connected to timers or switches to turn them on and off when needed.

The Laing Autocirc that I'm using is both NSF and UPC certified... no ill effects after 7 years. Perhaps it is that the small amount of (once) heated water is being mixed into the cold water line that makes it OK.

I've saved quite a bit of money, and continue to do so, and hot water at the faucet RIGHT NOW sure pleases the boss.

"The Laing Autocirc that I'm using is both NSF and UPC certified..."

So what?

Recommendations against drinking water that has been heated in a water heater or using it for cooking are all over the place.

"Recommendations against drinking water that has been heated in a water heater or using it for cooking are all over the place".

Apparently not in the NSF certifications or the Uniform Plumbing Code.

As I said, perhaps it is that a very small volume of the once hot water is being displaced into the water in the cold supply line and they are mixing which offsets (dilutes?) your subjective reluctance.

Watts also sells a very similar product to the Laing Autocirc and it also has the NSF 61 cert.

If you can point out any substantive scientific facts regarding the Laing Autocirc (or similar) device I'd like to read them.

This reads pretty good to me... http://www.tanksystems.com/NSFGoals.htm