OT: Water heater question

I've detected some leakage around the base of our hot water heater. It's a 75-gallon Rheem and is at least 10 years old. I suspect it's time to repl ace. Any of you have experience with a tankless system? How fast does a t ankless system deliver hot water?

Larry

Reply to
Gramps' shop
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a 75-gallon Rheem and is at least 10 years old. I suspect it's time to re place. Any of you have experience with a tankless system? How fast does a tankless system deliver hot water?

I thought about going tankless but I expect some gratitude when I install s omething.

Reply to
Michael

Like any water heater, it depends on how close it is the the faucet you are using. If it's installed across the wall from the kitchen sink, for example, you will have hot water almost immediately after the cooled water runs out of the pipes.

There's not much water running through the heat exchanger inside them and it heats it extremely fast.

Reply to
-MIKE-

When we lived in Sicily there was an antique one installed in the outside laundry room (thankfully). When you turned the hot water on that thing fired up like an F-16 and ran until the hot water was shut off or the propane tank--bombola--was empty. Worked fine.

In Japan there are a lot of them. They are more modern and smaller. Usually you would see a little one hanging on the wall over the kitchen sink. Never saw an electric one but I'm sure they exist.

Reply to
G. Ross

----------------------------------------------------------- Would have installed one on the boat when it was time.

--------------------------------------------------------------------

-------------------------------------------------------------------------- How close is the "load" to the heater?

How soon you get hot water is dependant on how much cold water you have to push out of the way to get to the hot water.

Same as with your existing set up.

Lew

Reply to
Lew Hodgett

The tank could be leaking from anywhere, water is going to show up at the bottom because of that gravity thing. ;~) So check the inlet and outlet pipes first. Gas water heaters tend to fail sooner than electric because of the greater extreme heating conditions that the tank must endure. The bottoms of the tanks are exposed to several hundreds of degrees temperatures. Electrics don't get much hotter than the water temperature at the faucet and the heating elements are in the water vs. outside of the bottom of the tank.

Assuming gas, some units and or building codes require special venting material. Apparently not any old vent will work in all cases. IIRC Swingman had one installed in one of his homes that he built and the vent material IIRC had to be stainless steel. And IIRC that ran about $100 per foot.

So you should for sure look into what exactly the cost will be installed before taking the leap. It may never pay for itself in savings if the unit runs in to the thousands of dollars, installed.

I do not think they offer any advantage other than energy savings and an endless supply of hot water.

Delivery of hot water will be relative to the distance the heated water will have to travel. You are only changing how the water is heated and when, not how quickly the water will be delivered. That is of course assuming your old water heater is not restricting the water flow.

Now with having said that, immediately after install you will get hot water much sooner from a tankless than from a new tank type heater which will have to heat the entire tank first.

Reply to
Leon

I think you know what you are talking about but just as much water goes through a tankless water and its heat exchanger as does a tank type water heater. The the big difference is that you are not heating water that is not currently being used and only the water that will be used at a given point is being heated.

Reply to
Leon

The physical makeup of the two are so different, it's hard to accurately compare. With the tank heater, there are two relatively small elements or flame to heat, say, 50 gallons of water. With the tankless, there are probably only a couple gallons capacity in the heat exchanger, with the "element" or flame completely surrounding all the water almost by the drop. Think of a car radiator and the air flowing through it. I would guess the heat to volume ration is probably 1000:1.

Reply to
-MIKE-

OK, we both know what we are talking about, I think. ;~) It was you mentioning that there's not much water running through the heat exchanger. I think what you meant to say was that the heat exchanger does not have much water in it at one time, unlike a tank type water heater.

Reply to
Leon

Oh, knock it off! Where's the beer?

Reply to
-MIKE-

Is it Ta-pa-to Or Po-ma-ta? ;~) Beah? Did you say Beah? LOL

Reply to
Leon

I'd first check the tank warranty - with a friendly Rheem dealer .. ... 10 years is a very early failure ! Mine - on propane - is ~ 23 years old and going strong ! In the past - I've discovered secret 10 year warranty on my Ford Taurus front springs ... and the SS tub on my clothes washer .. John T.

--- news://freenews.netfront.net/ - complaints: snipped-for-privacy@netfront.net ---

Reply to
hubops

It also depends on the water if minerals in the water quickly eat away the anode rod the tank will fail early. You probably have great water.

Reply to
Leon

"Gramps' shop" wrote in news: snipped-for-privacy@googlegroups.com:

Somebody asked this question a few days ago on the Home Shop Machinist forum. In summary, they weren't too fond of the tankless systems:

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Replacement

Puckdropper

Reply to
Puckdropper

I sure would not get stuck with one if I had any choice in the matter.

Reply to
clare

"Gramps' shop" wrote in news: snipped-for-privacy@googlegroups.com:

Check out Hybrid:

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Reply to
Baxter

FWIW: I've have planned, and effected, the installation of "whole house" tankless water heaters in three of the new homes I've built in the past ten years.

Your success depends upon a number of factors: the size of the house and distance of the unit(s) from fixtures; the number and type of hot water fixtures (flow rates must be determined for each fixture); the type of plumbing allowed in your jurisdiction for code purposes; type of unit (gas or electric); the brand; and, most importantly, the design, and accurate implementation of the design at installation.

Biggest issue with any hot water system is the time from the demand to the delivery. Distance is obviously a big factor, as well as any intervening devices in series (point A, through point B, to C, etc.).

Plumbing methods, utilizing a manifold distribution system (PEX makes this much simpler) can make a big difference in the time of delivery as it insures the shortest possible linear 'source to demand point' delivery.

It is my experience that, with whole house units, and without a manifold system in place, and if you have more than one bath, kitchen, and utility room with long runs of in series piping, your best results and satisfaction may require intervening auxiliary tanks and pumps, in some case multiples.

At this stage of the game I would steer away from electric units in the US.

With gas units, which must be vented to the outside, location of the unit is very important as the vent must be double-walled stainless and runs about plus $60/ft, installation not included. This can double the price of the equipment itself, and the labor/material needed to install

Rinnai is a good unit and worth the price. I've also installed one GE unit, at the homeowner's request, with no trouble thus far.

Use a dedicated tankless dealer for design and installation, not a plumbing company that does it as a sideline.

One of the exercises that must be performed is to calculate actual flow requirements of each and every hot water fixture in the house, the expected delivery temperature, AND, very importantly, _the ambient temperature of the water fed to the tankless unit_ coming into the house.

With a good gas unit, proper design of the piping system, and a knowledgeable dealer who provides the design and installation, you can get satisfactory results with on demand 'whole house' units.

My home owner's love them and have had no issues thus far, but it takes a good deal of planning, dedicated supervision of all details, and thus a good deal more expense than a regular hot water heater in order to install, and maintain, a tankless system.

Not for the faint of heart...

Reply to
Swingman

"Mike Marlow" was heard to mutter:

Also they need to be cleaned at least every two years or mineral buildup can become a problem.

I love the way our electric provider shows us how much of our electric goes towards heating water when there is nothing on the house to actually capture that data. I have told them to stuff their bogus statistics and focus on cost-savings they could pass along to the consumer.

I expect to be replacing my tank with a tankless. I have two friends in line for that and one already switched over. One is adding small heaters under sink(s) since they have a longer line to travel and want hot instantly from turn on. I have shorter lines and expect it to be the same as it is now, minus the electirc cost (going gas).

Reply to
Casper

"Mike Marlow" wrote in news:lpp3tc$4ll$ snipped-for-privacy@dont-email.me:

Here's a better one to check:

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Tells how it operates.

Note that there appears to be 2 types of "hybrid" - electric that uses outside (of the water heater) air, and this one which is gas powered and "hybrid" of tank and tankless plus high-efficiency.

Reply to
Baxter

"Mike Marlow" wrote in news:lpofkm$m8j$ snipped-for-privacy@dont-email.me:

It would seem to me that an obvious solution to the inconsistent water flow and temperature would be to put in a small insulated buffer tank. When the call for hot water comes, the demand is satisfied initially from the small buffer tank (5 or 10 gallons?) and the on-demand works to keep the buffer tank full.

Did I just describe a "hybrid" water heater?

My little point-of-use unit has issues with flow rate as well. The way it's designed, the flow rate of the water controls the temperature. If you get just enough flow to turn it on, the water comes out extremely hot. Also, if you start mixing in cold water it's easy to get to the point where there's not enough hot flow to keep the unit on.

Admittedly, this is an older unit (it's at least 7 years old, probably closer to 10). We are also about 100' as the crow flies from the well pressure tank, so add another 50' or so for pipe runs.

Puckdropper

Reply to
Puckdropper

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