can youtee off the furthest hot water line back to the hot water heater,with a return line andteeoff at bottom of water heater to circulate the water ,so you have hot water at all values without waiting

Hi 6kids

You sure can and here is a link to a great article discussing a gravity feed recirc. Line like you are suggesting:

How Does a Gravity Hot Water Recirculation Loop Work? | DoItYourself.com (http://www.doityourself.com/stry/how-does-a-gravity-hot-water-recirculation-loop-work)

They also make pumps for recirc. Lines but I'd try the gravity system first... should work very well in most cases.

Mark

Hi Kid and welcome to The Plumbing Page at ANHD.com. You're responding to a 3 year old dead threads so I gave you one of your own. Please check the date before you post. Thanks
Great answer by Mark! And here's what it looks like. Good luck, Tom

I have a gravity recirculation system and can say that it works, at least to an extent. However, I suggest that the recirculation return line be pipe into the cold water input line (along with appropriate check valves), rather than into the drain valve location. Will work better that way and is easier to do.

On a gravity recirc system, it will actually circulate better if the return is piped into the bottom of the water heater. If a pump is used, either the cold inlet or the bottom of the heater works just fine, with correctly placed checks of course.

it will actually circulate better if the return is piped into the bottom of the water heater

Why? The dip tube takes all input to the bottom of the tank where the drain valve is anyway and there is specific, identifiable advantage to taking the return to the cold water input.

Heat rises, so the hot return would have to fight the hot water at the top of the tank to get down the dip tube to the cooler portion of the tank. It will work, but not as effectively as piping the return into the bottom/cooler portion of the tank. Or have I been misinformed? Ive been wrong before, but is sounds logical to me.

Nope... spot on Lee... ;)

Thanks Mark. I thought so.

But..

As temperatures in the piping equalize (during non use), the amount of water circulating gradually reduces and the system seems to stop after a period. If the return is piped into cold water input, the use of hot water anywhere, even if it is not in the loop, brings make up water past point of the return piping, that siphons water from the return piping and restarts the circulating.

I'll concede that the return water gets heated buy the surrounding hot water as it makes its way down the dip tube and that is a detriment.
First thing in the morning my system has stop circulating. Open the kitchen faucet, which is not in the loop, and hot water is available at the upstairs bath faucet.

Normal activities keep it working during the day.

Can't argue with you on that. This is the reason I said it will work, just not as effectively as if piped into the bottom. Either way, it sure beats no recirc at all on systems with fixtures located long distances from the water heater. Good discussion here Harold. Thanks for sharing your experience.