I am building a new home. Walk out rancher. The plumber is recommending a hot water recirculation system. He wants to use a simple loop. I have been reading about various other systems (Watts, chillipeppers, hot lobster, gravity vs pump, etc.). Anyone have edxperience with any of the products out there? Any recommendations? Anything to avoid?

Use only "demand" systems that circulate only when there's a draw in progress, or you'll end up spending a lot more on hot water heating. Keeping the distribution plumbing hot 24/365 just in case somebody might be wanting hot water is a big waste of energy/fuel.

We have a "gravity" circulating system to our master bath, the farthest run in the house. The hot lines out and back are both insulated the whole way. I had them add a shutoff valve at the return side on the hot water heater. When we get to a point where the house no longer needs heating in the spring I close the valve and open it again in the fall when we start to need heat. In winter I figure the heat loss is to the house since the water lines run between two conditioned floors. It sure is nice having hot water right away. My problem is getting my wife in the fall to stop turning the shower on for a minute before she gets in, although I hear about it in the spring when she gets in expecting hot water and has to wait :)

When you shut off the return leg doesn't that dead leg let bacteria grow all summer?

Install an infared sensor on the pump power circuit and set it for how long it takes for hot water to get to the bathroom. You can use multiple sensors and multiple pumps for different parts of the house. If your not in the room the pump will not work.

greg, the plumbers said I could leave it off all summer with no problem. But I do turn it on at least every other week for a couple of hours for that exact reason. I do know our city water is about .2 to .4 ppm of free chlorine so it should be fine, but I would rather be safe than sorry.

I did find out there is no check valve in the return line. So I have also turned off the main hot water out and run water in that bathroom to “purge” the line as well.

I installed a Chili Pepper. Works great, it's "on-demand" and doesn't waste. You just have to remember to push the button before you draw water.

Posted By Jerry D. Coombs, PE on 15 Feb 2010 07:50 PM
I installed a Chili Pepper. Works great, it's "on-demand" and doesn't waste. You just have to remember to push the button before you draw water.

OK Jerry, for us Non-PEs, what is a Chili Pepper?

I don't like the idea of putting hot water from my tank back into the potable cold water (drinkable) line.