itsy bitsy tankless water heater?

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On Tue, 23 Sep 2014 06:11:45 -0700 (PDT), trader_4

If you are in a multi story and your water heater is in the basement, you can make a gravity driven recirculator if you can run the pipe. My father did that in our house but we had a central stack chase that went from the basement to the attic, catching the wet wall on the second floor along the way. He was able to push a copper tube up from the basement building length as he went until he got to the 2d floor bathroom. Tie that to the hot water line and the bottom of the water heater and it will thermal siphon.
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wrote:

That used to be very common, not sure how they build up there these days.
The beam pocket usually has a course or two of brick under the beam or they use a solid block.
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On Tue, 23 Sep 2014 10:11:33 -0400, Stormin Mormon

The good thing is it doesn't have to be big pipe. A 3./8" copper or Pex tube is plenty. You can fish Pex pretty easily. If the place you want to recirculate to is higher than the water heater, you don't even need a pump.
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On Tue, 23 Sep 2014 09:44:33 -0500, Unquestionably Confused

That assumes you already have a :"loop"
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g,
The cold water pipes are used as the return loop. It may heat up the cold water a bit during the recirculation. Probably not much of a problem. I like the programable timer.
Dave M.
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On 9/23/2014 10:34 AM, snipped-for-privacy@aol.com wrote:
[snip]

You really ought to try reading or watching before typing, sir.
The return "loop" is the cold water pipe, utilized by the installation of a by-pass fitting at (generally) the lavatory fixture furthest removed from the water heater.
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wrote:

Put a turkey roaster under it.
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On Tue, 23 Sep 2014 08:53:01 -0500, Unquestionably Confused

By code here in Ontario Canada extra piping IS required. You can NOT allow any backflow into the coild water side. Even a "mixed shuttoff" on the tub shower is technically illegal.
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On Tue, 23 Sep 2014 09:44:33 -0500, Unquestionably Confused

Works but illegal in most jurisdictions
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wrote:

Insulating the hot water line is a good point. If you are heating your house the waste heat from the hot water line is no big deal but if you are running the A/C, that is money wasted twice. Nobody actually seems to insulate those lines tho, at least not as a common practice. Here in Florida the lines are in the attic so it is not that big a deal I guess and my water heater is outside the A/C envelope.
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myself.

the

pleasure

The lovey Miseries Bob wanted a water-squirts-the-butt toilet seat. And I have to say that it is handy to have, especially for them as has disabilities or old timers disease. Every toilet in a hospital or nursing home should be required to have one. Amazing that they are not covered by Medicare... butt I digress....
Anyway, it has a small tank and keeps it hot. I don't know the electricity cost but (and this is a big butt) it's rated at 100 watts.
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On Tue, 23 Sep 2014 11:16:05 -0400, snipped-for-privacy@aol.com wrote:

me too. In my experience they last about 5 years in that service.
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On Tue, 23 Sep 2014 11:31:57 -0400, snipped-for-privacy@aol.com wrote:

I don't get it.
Assume the water heater is in the basement and the place you want to recirculate it too is on the 2nd floor.
If you don't have a pump, how does the water know which pipe to go up, and which pipe to go down?
When the faucet is turned on, why doesn't it go up both pipes, and when the faucet is turned of, then stop in each of them?
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On 9/24/2014 4:07 PM, micky wrote:
[sni]

Convection, thermodynamics, call it what you will.
Heat rises. The hot water will rise up the pipe (just like it rises to the top of the water heater tank. Since water is non-compressible, it has to displace itself and the cooler/cold water is forced downward (via the PEX in this case). The trick is having a one-way valve calibrated to allow the hot water to flow over to the PEX (or in the example I had with the Watts recirculator) or the cold water line.
That's where it gets tricky since both the hot and cold water sides are at the same pressure - or should be.
So, while it can be done without a pump, you probably will really need to use one to make this work. But, yes, fishing PEX would be a helluva lot easier than plumbing a return line with copper but still not as easy as using the Watts system without a dedicated return line.
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wrote:

It goes out the pipe at the top of the water heater. The cold water ALWAYS enters at the bottom

The THEORY is the water will thermosyphon when the tap is closed (the "loop" bypasses the tap. I can't see it working without a dedicated "return" line. Using the cold water line as the return just sounds all wrong to me - not allowed here, in any case. With a dedicated return, even a smaller pipe, like 3/8" tube, I can see it working, but not as well as a pumped system.
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On Wed, 24 Sep 2014 18:58:12 -0500, Unquestionably Confused
I

I have one of these systems in my house. I didn't install it but as far as I can see there is no check valve in the system. There is a cut off valve for those who want to shut it off in the summer to avoid the slight heating to the house. In the winter "waste" heat just heats the house and costs nothing to run. It only takes a very small amount of circulating water to provide for the instant hot water.
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On Wed, 24 Sep 2014 20:07:03 -0400, snipped-for-privacy@snyder.on.ca wrote:

I get it now. Thanks, and thanks Unq
I could run a pipe up my laundry chute, and there is almost a foot of space in front of the chute and behind the wall. AFAIK that's not used for anything.
I would need to go horizontal just below 2nd floor level, to get to the other side of the hall. That is, the chute etc. is across the hall from the bathroom, so I should readlly take up the carpet, cut a trench into the floor of the hall, and run the pipe, maybe PEX, under the hall floor, which I'd have to connect to the vertical pipe (or bend to be vertical) on one side of the hall, and have to bend up to come through the sink cabinet floor on the other side. The cabinet floor is removeable, but then there is the bathroom floor 2 inches below that. :-(
Sounds like a lot of work, and Ill end up having the hall torn up for months while I try to make connections on either side. Unless there is a clever way around all this.
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On Saturday, September 27, 2014 11:06:02 AM UTC-4, micky wrote:

That would be the pump that sits under the sink and uses the cold water line as the return. It's clever, as long as you don't intend to drink any of the cold water from a fixture anywhere along that pipe route.
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On 9/27/2014 1:37 PM, trader_4 wrote:

Actually, the Watts system has the pump installed at the water heater. There is only the by-pass valve at the lavatory to allow use of the CW pipe as the return.
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On Sat, 27 Sep 2014 15:25:18 -0500, Unquestionably Confused

Well I do drink water from the bathroom when I'm thirsty, and also from the kitchen sink, which -- I'll check again -- afaicr uses much of the same line. In fact I fill up bottles of water for the fridge there.
OTOH, when the house was new a couple times I made cocoa straight from the hot water. Tasted okay to me. Vinyl and glass water heater liner and copper pipes: can hot water make me sick, ?
And I could let the cold water run until it was really cold. Of course that's like letting the hot water run, and the whole reason for this project was to avoid that.

I've marked thel links but been too busy to read them. I will.
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