Water heater mineral residue?

[Mike Armstrong]

A question for the plumbers out there: A couple months ago, I decided to replace my 18-yr-old water heater before it caused some serious problems. For several months prior to that (and even now, but to a much lesser degree), there's this white material coming through the hot water pipes and occasionally clogging the flow restrictors in some shower heads and faucets. Are these accumulated mineral deposits from the old tank? It seems to be smooth on one side (I assume the tank side) and rough on the other, and there seem to be a few rust-colored spots here and there.

Ideas?

http://i301.photobucket.com/albums/nn47/wdcr8ns/waterheater.jpg

Mike

[Ken Fitzgerald]

Mike,

I suspect the deposits are originally from the water. When the water is heated, they form into large crystals around the heating elements in electrical and near the heat chamber in gas. To keep the sediment from building up within the water heater, it's recommended that you drain and clean water heater tanks on a periodic schedule. I don't know if the deposits you saw were caused by deposits that naturally occur within the water or caused by the water heater. I would suspect it's within the water itself.

[Joe Pelonio]

Mineral residue (calcium) does reside in the hot water tank, and it's recommended that it be flushed annually, especially if you have relatively hard water, as in most wells. I do not recommend a sudden flushing if it's not been done in the last 6-10 years though, since it can dislodge rust/mineral that is keeping it from leaking.

If you are still getting it moving through to the screens, you can try flushing the pipes. Hopefully much of it is gone with the new tank, but
you could also have some in the pipes themselves.

That will allow anything loose to pass out and reduce the need for screen cleaning until more loosens up over time. Simply remove the screens on all the faucets. Then run the faucet closest to your water meter or well pump full force for 5 minutes.

Close, and do the same at the next, and so on until all of them are flushed. Flush each toilet while the nearest faucet to it is running.

[Al Willits]

Two things it can prob be, mineral deposits or dip tube pieces, try burning one of the pieces, the plastic dip tube will burn, minerals won't.
I'm also told the plastic will float in water and minerals won't.

Letting a couple of gallons out of the drain valve on a regular basis will help, but that's once a month or so, once it builds up and solidifies it take a deliming to remove, we tell customers to either do it often or not at all.
Like Joe says, if you open that drain valve after a few years it may not seal when you shut it off, a brass garden hose end cap with a rubber washer may seal it up if the threads are still good on the drain valve though.

Al

[Richard M. Wolfe]

Where I live the municipal water is from wells, and the water percolates through limestone deposits several hundred feet thick. Consequently we have very hard water. Calcium builds up fairly quickly in water heaters; it's not unusual for a water heater at the end of its life to weigh a couple hundred pounds.

I checked into the reason the "scale" built up so fast. Nearly everything has higher solubility in warm water than cold water. For instance, you can dissolve more sugar in a cup of hot water than cold water. Not so for some calcium and magnesium salts (mainly calcium sulfate and magnesium sulfate) - hot water holds less and they precipitate. I can't remember the molecular reason but that's why scale builds up in a hot water heater. That's assuming that what you have is mineral scale.

[Craig Summers]

You might want to figure out what kind of Anode that you have in the new tank. There are several types and are explained here (http://www.waterheaterrescue.com/pages/WHRpages/English/Troubleshooting/stinky-water-in-hot-water-heaters.html)

A few tips (http://www.waterheaterrescue.com/pages/WHRpages/English/Longevity/sediment-in-hot-water-heaters.html) for removing sediments
If you have a gas water heater, it might take more effort to flush sediments because of the Flue
For an empty tank, you might want to replace the drain valve with a quarter turn valve, and replace the dip tube with one with a rounded end.

I did see something that you might also want to think about

There's something few realize: water is a chemical and one that is constantly changing. The water that flows out of the tap this evening may be different from that from this morning, either because of what's in the ground or because water companies have changed their sources of supply or added something new to it.