Fill Water Heater from bottom ?

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Is there anything wrong or dangerous about my idea to supply cold water input to a gas Hot Water Heater via the drain opening? I would include a TEE and a boiler tap so as to permit future draining. Also would cap old unused inlet on top.
Reason for this is to mitigate damaged dip tube. I do not have headroom to replace dip tube. Heater is 75 Gal (very heavy) and I prefer not to have to tip it to permit insertion of the new dip tube.
Thank you.
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On 1/12/2014 4:16 PM, Newton wrote:

Seems to me that it might be far simpler to replace the damaged dip tube with a multi-sectioned replacement fashioned on site.
Cut whatever you must to remove the damaged dip tube and then cut the replacement into sections that will fit your head room joining them (dope or solder) as you go.
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On 1/12/2014 5:31 PM, Unquestionably Confused wrote:

Good moment for a flexible dip tube with a little bit of a weight on the bottom. Like chainsaw fuel pickup.
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On 1/12/2014 5:08 PM, Stormin Mormon wrote:

PEX maybe. Depends on the configuration and materials used in the dip tube inlet.
There's always a couple of ways to skin that cat.
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On Sunday, January 12, 2014 5:16:27 PM UTC-5, Newton wrote:

nput to a gas Hot Water Heater via the drain opening? I would include a TE E and a boiler tap so as to permit future draining. Also would cap old unu sed inlet on top.

to replace dip tube. Heater is 75 Gal (very heavy) and I prefer not to hav e to tip it to permit insertion of the new dip tube.

If you can get the drain out you can do that. On old hw heaters I often ca n't get any of the things threaded into the pipe threads off without it str ipping most of the thread out. Probably depends on your water quality thou gh. Good luck and let us know if you are successful.
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jamesgang wrote:

If the drain has a hose tap on it and you don't want to risk stripping the tank opening threads by unscrewing the tap you could couple to the tap's outlet with a female hose to NPT pipe thread fitting like this one:
http://tinyurl.com/mttle7q
Plumb it up, open the tap and you're good to go.
Jeff
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Jeff Wisnia wrote:
Sorry, I didn't get the TinyURL quite right.
It is:
http://tinyurl.com/n3gtt2e
Jeff
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On 1/12/2014 5:16 PM, Newton wrote:

I was able to do a dip tube with not enough space, cause it angles in at the top.
To answer your question. I gave it a few minutes thought, and it should work OK. YMMV, IANAP.
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On 01/12/2014 04:16 PM, Newton wrote:

The reason it's heavy is simply because it's full of water. If you drain it, it will be no problem to tilt.
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Philo - I installed the thing myself. 75 gal AO Smith. It's heavy empty. Trust me.
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snipped-for-privacy@gmail.com wrote:

Robert , I had a simil;ar situation . I used an NPT to Compression fitting , reamed it out so the tubing would pass thru , and used soft copper tubing . Straighten it as you feed it thru the fitting <already installed in your tank> until you feel it bottom out then back it off a little . It's also nice to give the bottom end just a bit of bend so the water swirls at the bottom instead of causing turbulence that might douse a shower user with a cold surge . Mark the tubing so you can orient that bend ...
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wrote:

How much headroom do you have?
I think 18 inches is easily enough, and now that the topic has come up, I think my 10" would be enough. I'll just have to bend the dip tube a little more. It is once clear plastic, now dirty everywhere
I had an A.O Smith water heater, and now I have a Sears WH. I think it's made by AOSmith because it's the only one I could find that has the input and output the same distance apart as the original. And the owners' manuals were very similar with the same drawings and pictures, iirc.
When I tore the first Sears one apart, I saved the dip tub and it's pretty flexible. I have a big storage shelf hanging from the ceiling above the WH so I only have about 10" head room and I think it would be enough. Like Chris says, you put it in at an angle until in my case, only 10" are left.
My dip tube goes to the bottom and then towards the permimeter, and then bends to swirl the water around the bottom, which iirc is suppose to pick up sediment** The last 2" are molded into a sort of nozzle. But before you replace a diptube, if the replacment is not symmetric, find out how yours is oriented, and mark the top of the tube so you can orient it as intended. In my case that would mean not pointing the open end to the center or the outside, but parallel to the outside so it made the water swirl.
** (although that would clog screens too? Maybe the idea is to swirl it around when it is still microscopic, so it exits with the hot water, and it's too small to clog anything?? ) When I tore the second water htr apart after 8 years (probably a mistake to replace it. Maybe only electrical parts were bad and I got confused, or maybe the dip tube had come off (there is damage at the top, but I might have made that during destruction.) there were only about 2 or 3 tablespoons of sediment in the bottom At the rate it was going, it would take 80 years before the sediment reached the electric elements, which is bad with electric WH. With gas it's different I guess because the flame is underneath. )
Actually my diptube was fine after 8 years, Is this what's bothering you? http://voices.yahoo.com/how-replace-cold-water-dip-tube-clear-up-8819775.html
If your WH is made during the problem years and your worried about it falling apart and clogging screens, it's not enough to feed the water heater cold water, you have to remove the old dip tube too, don't you.
http://www.familyhandyman.com/plumbing/water-heater/how-to-repair-or-replace-defective-water-heater-dip-tubes/view-all http://www.dummies.com/how-to/content/how-to-replace-a-water-heater-dip-tube.html
Despite what this says, mine is not 3 feet it's over 4.5 feet. and then another 14" for the curly part at the bottom. It's almost as tall as the water heater. For gas it would be shorter because the gas flame takes up space underneath.
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On Sunday, January 12, 2014 10:42:41 PM UTC-5, micky wrote:

Kind of what I was wondering too. Is this a problem with new WH's that you would install today? Or just a problem some had in the past? You would think by now they would have a dip tube solution that would last the life of the tank. Personally, I've never had a dip tube fail.
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... major snippage occurred...

I had a dip tube fail on an A.O. Smith water heater about 20 years ago. When I replaced the water heater (it was pretty old and I wanted a bigger one anyway) I pulled the old dip tube just for fun. If I recall correctly it was about 6 inches long.
That means that I was essentially splashing cold water right onto the hot water at the top of the tank and then drawing it off immediately. A hot shower lasted about a minute or so and it was lukewarm from then on.
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On Mon, 13 Jan 2014 08:17:28 -0800 (PST), " snipped-for-privacy@optonline.net"

I had meant to quote the second link "Faulty dip tubes in water heaters made between 1993 and 1997 may cause hot water problems and clogging at faucets."
"If you have hot water problems (loss of water temperature and/or loss of water pressure at water delivery points) and your water heater was made between 1993 and 1997, you have a lot of company. During that time, nearly all the major water heater manufacturers were buying the same defective plastic dip tubes from the same manufacturer and installing them in their gas and electric units. Unfortunately, depending on your water chemistry, its pH and the temperature setting of the water heater, these tubes eventually break, crumble and/or dissolve into various size pieces.
The pieces clog strainers and filter screens on appliances and faucets, and the partial or complete absence of the dip tube severely harms water heater performance.
The role of the dip tube is to direct incoming cold replacement water to the bottom of the tank for heating. While it warms, the dense, cold water stays naturally segregated from the warmer, lighter water floating on top. The water for faucets and appliances comes from the hot layer on top. If the dip tube is missing, the cold incoming water mixes with the hot water at the top of the tank and you wind up feeding the house with tepid instead of hot water.
If you’re having hot water problems, first see if you have a water heater made during those bad dip tube years. Often, the first four numbers on the serial number are the month and year of manufacture. If the third and fourth numbers are 93, 94, 95, 96 or 97, it could be affected. If you have a bad unit, there are two options. First, replace the water heater and flush all the faucet screens and filters throughout the house. (If your water heater is more than 10 years old, it’s nearing the end of its life, so it’s probably worth replacing.) New water heaters have dip tubes that’ll last as long as the water heater.
Or second, replace the defective dip tube with a cross-linked polyethylene one and flush the debris out of the water heater and the screens and filters. You may have to flush the system more than once. "
or the third:
"That White Crud in Your Faucets May Be a Sign of a Decaying Hot Water Heater
My friends were certain that my hot water heater was plugged with calcium precipitate, and that I would need to purchase a new unit. Instead, the problem was a ten-dollar part that required about one-hour to replace. It's called a "Cold-Water dip-tube", and chances are good that you'll need to replace yours as well.
A cold-water dip-tube is a three-foot plastic pipe that routes cold water to the bottom of the hot-water heater. The cold water is heated, and then rises to the top of the tank, where it flows out to the house. Without that pipe, incoming cold water would immediately mix with outgoing hot water. Not very efficient.
In the mid 90's, many hot water heaters used defective plastic dip-tubes, and by 2010, they are breaking down into a fine plastic granulate. This is the first clue that your dip-tube is defective '" you'll be noticing a reduced flow through many of your hot-water faucets, caused by a build-up of these white granules. If you unscrew the screen from the end of the faucet, you can flush this plastic from the screen, and flow volume will be immediately restored '" but only for a week or so. After that, you'll again find a build-up of plastic bits. My friends and I mistook this for calcium carbonate particulates.
A shortage of hot water is another sign of a failing dip-tube. Since the water heater isn't working efficiently, the temptation is to turn up the water heater thermostat. But that doesn't solve the problem."
Instructions follow althought the part about unscrewing the diptube doesn't seem to apply to my WH from 20 years ago.
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I just watch this weekend's episode of Ask This Old House. They did more or less what you are asking to do...sort of.
Try this link. If it doesn't take you directly to this week's episode, search for "Irrigation, Heat Pump" and watch the second part, the part about installing a heat pump on a water heater.
http://www.thisoldhouse.com/toh/tv/ask-toh/video/0,,,00.html
They installed a heat pump on a water heater and used a special single entry valve in place of the drain valve. The single entry valve not only let water flow from the tank to the heat pump it also allowed the water from the heat pump to flow back into the tank through the "pipe in a pipe" system. In addition, it had a drain valve on the end to allow the tank to be drained.
It looks something like the valve in the middle of this PDF (scroll down to the bottom of page 1) but with a drain valve on the end instead of the rubber piece.
http://www.heatinghelp.com/files/posts/7425/Steam-to-hot-water-conversion-valve.pdf
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One thing you can count on is stirring up all the gunk that has settled at the bottom of the tank. You will have it mixed in with you hot water.
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On Monday, January 13, 2014 8:40:08 AM UTC-6, CRNG wrote:

Since the water inlet is at the bottom anyway and the outlet is on top...it should make little difference.
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On Mon, 13 Jan 2014 07:14:32 -0800 (PST), Bob_Villa

Seems like it would depend on the size/weight of the sediment. Most of the sediment I've ever seen come out of a tank drain was pretty light and small. It looked like it could be readily re-suspended. I guess the OP can check what it looks like by draining a few gallons from the bottom of the tank.
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wrote:

More than one person here has advised not to do that. Crud gets in the vavle they say and then the drain valve can't be closed. I've never tried.
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