Domestic Tank Hot Water Heater Trouble

[tmajor]

This is a topic, which I wasn't totally unaware of, but didn't give it too
much consideration.

My 1998, 40 gal. LP hot water heater, seemed a bit strange a year or so
ago. It seemed like the water was cooler and the burner didn't seem to
respond as quickly. I thought the burner control was getting marginal. I
may have flushed the tank, I don't recall. It's been usable in the
meantime.

About a week ago, i noticed the hot water coming into the clothes
washer, was slower than normal. I took off the hoses and found the hot
hose was filled (nearly plugged) with white shards of ???. After some
Googling, it seemed like it could be disintegration the "dip-tube" in
the hot water heater. The "dip-tube" is a plastic tube, which goes from
the cold water inlet to the tank, down toward the bottom (internally),
so the cold water does not mix with the hot, right at the top of the
tank.

Because the tank is 19 years old, I felt it wouldn't hurt to replace it,
at this point. However, the new tanks are a couple of inches taller,
which presented problems with venting in my current configuration.

So, I flushed the tank, numerous times, all the while getting large
shards of plastic, rust and "goo". .... some, I had to pull out with a
wire or pliers. Finally, I removed the cold water line, to find that the
dip-tube was totally gone, except for about 1" at the top. To get the
most of the old deteriorated dip-tube out, I removed the boiler cock at
the bottom. After installing the new dip-tube and re-connection of the
water supply, I flushed it more thoroughly, until all signs of plastic
and goo seemed to be cleared.

In the pictures, you'll see the plastic, one piece which is about a 6"
piece of melted plastic. Also, in the one picture, you see my foot
prints in the goo (about 1/4" deep), which had drained. (I finally, just allowed the water
to run out on the floor and to the outside drain.)

So, if you see a change in water temperatures, etc., the first thing
would be to open the drain cock and flush the bottom ... should probably
be done once a year. Keep in mind, that the dip-tube could be be going
bad. Electric heaters could loose the dip-tube, but it probably wouldn't melt on the bottom of the tank.

The water temperature is more consistent, now. In the meantime, I can try to figure out, how to install a taller tank, when needed.

A melted dip-tube can't be healthy!

 

[Citydude]

I just replaced my water heater with the same symptoms. I had the same height issues until I discovered these. It took me 10 minutes to install the fittings.

U368FLEX24LF - SharkBite U368FLEX24LF - 1/2" Sharkbite x 3/4" FIP Flexible Water Heater Connector - 24" (Lead Free)

 

[B7510HSD]

I just replaced a 40 gallon electric unit last week and it was the same diameter as the old one but a foot shorter!

 

[RNeumann]

If OP is going through all the trouble on a 19yo tank don't forget the anode rod. I'd also replace the factory hose bib style drain with a full port ball valve.

 

[tmajor]

Yes, I used a SharkBite fitting to reconnect ... they are a life saver! Also, replaced the plastic hose bib, as it partial broke off, when removing it. Anode, hmmm .... maybe, if things seem to be going in the right direction. My original tank was probably a "short tank" and at this point, the short tanks are a couple inches taller.

 

[Deere Dude]

Check the pressure relief valve to make sure it works well.

My water heater was installed in 1996 I believe and was a 50 gallon gas. It worked fine but wanted to replace it anyway because I knew it would go out when I didn't plan on it so I changed it on my time frame. I did notice that the temperature pressure relief valve would not have worked if it wanted to because it was all plugged up with scale.

 

[JRobyn]

We get the bottom of the tank filling up with little white "shards" too, but they are flakes of calcium that plate onto the electric elements and then flake off due to the thermal cycling. After a while, the bottom of the tank will get so full of flakes that they cover and insulate the lower element, so it overheats and burns out. By the time the heater gets to this point, the bed of flakes is usually so deep and packed that it's impossible to remove by just flushing. Removal of the element and the drain valve and scooping it out can sometimes resurrect them. Regular, at least annual, flushing is the only PM.

 

[ray66v]

Keep in mind, hot water tanks come in "short" and "tall" versions now. Make sure you get the short version, if you have height issues.

I do not recommend flexible hoses, especially, on a water heater. Sooner or later, the combination of the chlorine, and the heat will cause the pipe, inside that pretty braiding, to fail.

I am not interested in hearing from those who have done it without incident. I have seen them fail, so I know they can. And, they fail at the worst possible time.

The last one I repaired, was last summer. A pin hole on the hot side of the tank, released steam into the laundry room, for days. It caused substantial damage.

I had told the homeowner, (an engineer), not to use those hoses. They add a potential failure point. But, of course, as an engineer, he knew better.

The tank is now properly plumbed with copper pipe.

I will not be very surprised, if Shark Bites also eventually become a failure points.

I know some people hate soldering pipe. Usually, because they are not any good at it. It's really not hard. Watch some video's, or get help. Done properly, it's permanent. And, that's one less thing to worry about.

 

[TemporaryKubotaOwnerMark]

If OP is going through all the trouble on a 19yo tank don't forget the anode rod. I'd also replace the factory hose bib style drain with a full port ball valve.

If OP is going through all the trouble on a 19yo tank don't forget that he's going to be replacing it soon anyway when the bottom starts leaking and he might as well have saved himself all that trouble.

Tanks are available in all kinds of different configurations. A bit of research online would have found a tank that fit.

 

[tmajor]

Tanks are available in all kinds of different configurations. A bit of research online would have found a tank that fit.

Not so, my friend, unless you have different online sources, than i do. All of the "short tanks" are taller than they used to be, due to the regulations, with burners having to be further off the floor, fire guards, etc..