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.
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.
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.
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.
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 ...
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,
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
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.
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.
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.
On Mon, 13 Jan 2014 08:17:28 -0800 (PST), " email@example.com"
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
"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
The pieces clog strainers and filter screens on appliances and faucets,
and the partial or complete absence of the dip tube severely harms water
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 youre 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, its nearing
the end of its life, so its probably worth replacing.) New water
heaters have dip tubes thatll 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
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.
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
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
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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