There is no return. It's purely a convenience thing.

Circulating hot water consumes extra power to run the pump and keep the water in the lines hot at all times. That's why a lot of the pumps have built in timers to minimize the number of hours the water circulates. Your water rates would have to be sky high compared to your power rates to realize any savings.

Thanks, Creek side. That is pretty much what they said. :)

How about putting the water heater near the kid's rooms, kitchen, etc., and then using a tankless just for the master?

We went through this just recently on my GF's house and her brother. Both have long ranch plans. He chose not to put a circulation pump on. You go to the 1/2 bath or kitchen and wait 2-3 minutes for hot water to wash your hands...Or just give up. Hers we put the pump in for about $500 extra. The pump is very low voltage and can be set on timers to be off at night if you chose. But they pay to run well pump and sewer pump ( your situation may be different and pay for volume of sewer) and that costs you when water is wasted to run down drain while waiting for hot water. So as stated by others it can save money in ways but its mostly the convenience of having hot water NOW.

We just purchased a fixer  3300 single story with the water heater on one side of the house and the master bath on the other. I am not exaggerating when I tell you that I get up in the morning and start the shower. I then use the toilet, walk to the kitchen to make myself a cup of coffee, and back to the bathroom. By the time I am undressed  the water is warm and I only have to wait a bit longer for it to be hot enough to step in. Oh  and I live in So Cali  so IÂm sure it would be worse in colder climates.

We can tell that the house originally had a circulation pump and we want to install one again. I *hate* wasting all that water!

Our new build has the water heater at one end of the house, with almost all hot water using fixtures and appliances clustered nearby. The exception is the master bathroom, whose fixtures are about 60 feet away. We have included a timed circulation pump for that line.

jeri -- your description sounds like what our house might be like. Sq footage is 3080 and I can imagine when the kids are a bit older and showering in the morning before school, letting the water run for 5 minutes! :) It seems like it might be worth the $500!

Something that doesn't get mentioned much for such situations is constant wattage heat tracing on the piping.

At 4w/ft it is inexpensive to operate unless you live in a bowling alley.

Unlike a circulator pump, there are no moving parts to wear, leak or make noise. No need to dump warm water into the cold line, as some systems do, or need a return line, like others.

Like a circulator, such a system requires a control (t-stat) and insulation. The better the latter, the less power consumed. Hot water is immediately available.

OP, in your case, where usage is far from the heater, I'd consider another heater located nearby. Despite increase in electric rates, tanks are cheap to purchase and install and have very low standby losses.

Alphonse -- I've never heard of constant wattage heat tracing. How much would something like this cost in materials and insulation? Why the t-stat? Wouldn't you always want the water to be hot when you turn the hot on? I'm confused...

Gravity recirc. requires no pump and no electricity and works. I'm not an engineer, but my DH is and he put it in our house. Every faucet has hot water instantly. If you can find a plumber who knows their stuff it can be done. If you want I'll ask DH to give an explanation when he's home.

Gravity recirc. requires no pump and no electricity and works. I'm not an engineer, but my DH is and he put it in our house. Every faucet has hot water instantly. If you can find a plumber who knows their stuff it can be done. If you want I'll ask DH to give an explanation when he's home.

Yes ... but it can cost you a pretty penny in operating costs.

For example, I added a recirc loop to our house. Originally, it was controlled by a thermostat, so when the temperature of the water in the line dropped below a certain point, it would turn on and refresh the lines with hot water. This resulted in the hot water heater running much more than it would otherwise (6 times a day instead of 2) with the end result being the additional gas used costing around $15 / mo.

I've since updated the system to work via motion detectors and have seen the HW heater cycle time (and my bills) return to normal. Well, "normal" except that I wait 5 seconds for hot water, not 60.

There are different types of heat tracing. I used constant wattage in my system, and can't comment on other types. Aptly named, it produces heat with no limit, thus the need for control(t-stat)...exactly like your water heater.

Memory isn't good, so I can't give prices (my system is over 10 years old)but IIRC, there is a minimum footage purchase (10' maybe)and then per/ft. cost.
Insulation cost is a wash- any system should be insulated. My system is designed to maintain a temp. just under the heater setpoint. The longer the insulation maintains static condition the less power used.

Cost for my system with expensive, quality pipe insulation was well under a circ. pump. Installation requires no plumbing, but does require minor electrical skills if power isn't nearby. Installing the trace and insulating will take longer than installing a pump (without return line- which could extend time considerably), but is not skilled work, simply conscientious.

My situation has 20' of trace,@5W/ft. At the old kWh rate (just increased), operating costs were penny/hour. Note the system does not operate continuously. Circ. pumps consume power starting at ~400W, 4x my consumption, though of course they are intermittent duty too.

The heat loss back to the water heater in the gravity recirc loop is not significant. The heater may cycle more more but not enough to have a big impact on cost.

Cost to run gravity recirp loop - minimal.
Instant hot water all the time, every time - priceless.

"The heat loss back to the water heater in the gravity recirc loop is not significant."

It is more than a pump on a timer.

The heat loss is what drives a gravity loop.

No heat loss, no circulation.

"It is more than a pump on a timer."

I disagree, but that may be YOUR experience, it's not mine. However, pumps don't last forever, neither do timers. Both require repair/replacement at some point. We have no operating cost and beyond that what little heat loss there is, is captured within the house and in my climate we have far more heating days than cooling days. YMMV.

We recently completed a two-story walkout with utilities in the basement.

The recirculating pump was hooked up wrong and we needed to wait a while until the plumbers could come back to fix it. In the meantime it took at least two minutes plus to get hot water. Even though we have a well it was definitely wasteful. Now that it's working correctly it's great.

I don't look at it as return on investment. It's a quality of life thing and the bonus is conserving water at the extra expense of a little electricity.

Still, $500 seems steep for a small pump and a few fittings and shutoff valves assuming it's placed near an outlet.

Just a couple of points.

A house built with a loop for recirc will do worse without a pump running than a house without a loop as far as time for hot water

does a pump fail. Sure but it could easily be 20 years

My builder estimated $20 a month in gas to feed a loop. I did some math and I think I got numbers around $15 per year for an insulated loop on a timer with pex tubing. Do uninsulated copper and you can quadruple that.

As far as heating your house with the heat loss from your loop. That is a bit like using incandescent bulbs for the same reason. It all depends on the relative efficiency. The incandescent argument falls apart because no one in the north uses electric strips which would have similar eff. If you use gas for both then it isn't a bad argument.