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.
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.
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.
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.
Good moment for a flexible dip tube with a little bit of a weight on the bottom. Like chainsaw fuel pickup.
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.
The reason it's heavy is simply because it's full of water. If you drain it, it will be no problem to tilt.
Philo - I installed the thing myself. 75 gal AO Smith. It's heavy empty. Trust me.
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?
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.
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.
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.
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.
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:
Plumb it up, open the tap and you're good to go.
Jeff
Sorry, I didn't get the TinyURL quite right.
It is:
Jeff
On Sun, 12 Jan 2014 14:16:27 -0800 (PST), Newton wrote in
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.
Well. the link to This Old House from DerbyDad demonstrates that one *can* safely remove a boiler tap, *and* one *can* inlet water from the bottom. S eeing is believing. Thanks DD for this.
Re getting stirred-up sediment in the output, I don't see how that would ha ppen as the outlet is still at the top. That's a long way up for the heavy sediment to go. Besides, a working dip tube delivers the water near the b ottom anyway. That's the point of it.
Finally, to Mr. Philo: 75 Gal HWH is big *and* heavy, without the water. I put it in (empty) myself. If you think it's not, maybe you could come he re and tip it while I watch how you do it. ;-)
Since the water inlet is at the bottom anyway and the outlet is on top...it should make little difference.
The question about sediment was addressed in the ATOH segment. Since the special valve they used is essentially a pipe-within-a-pipe which limits the size of the outlet pipe going to the heat pump, there was some concern about the sediment. The answer was that the tank might need to be flushed more often to ensure that the sediment didn't clog the outlet pipe.
I am aware that the difference between your application and the ATOH application is that you won't be taking water from the bottom of the tank, but I wanted to point out that the sediment issue was indeed addressed in that episode.
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.
On Mon, 13 Jan 2014 07:14:32 -0800 (PST), Bob_Villa wrote in
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.
Just watched an Ask This Old House episode where they used a heat exchanger to supply warm water to a water heater through the drain hole.
So, I don't think feeding water in through the drain is a problem.
... 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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