White gel coming out of water heater

JoeWras

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Sep 18, 2012
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This is likely a mystery solved. I was going to ask ya'll what's going on, but upon further deep searching, it appears I've run into lime deposits.

Situation: decided to actually flush and drain my water heater on a schedule. I've never done this. Due to drought, I caught the water in buckets and was pouring it in my rain barrel, which is empty. Out came this blue-ish gel.
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I thought to myself: "Joe, is that plastics from the dip tube? Uh oh. Only two years old?" Well I forged ahead and had to finish the final drain on the driveway to get proper drop for a complete drain. More came out.

This morning I wake up to find nice white powder, and no more gel balls.
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The funny thing is we ran into this gooey gel at my non-profit last summer when we had to work on a water heater. Again, at that time I thought it was the dip tube.

After seeing the powder, I did a deeper search. Sure, the top things that come up are: blown dip tube, and, rotten anode.

But after only 2 years? Come on.

Further searching reveals that lime will precipitate out of the water in these tanks. Flushing is actually a good thing before it becomes hard scale. I've worked with lime for my lawn. It was always powdery. Never this goo, almost like a silica gel goo.

So I guess I'll continue the flush. This may be a good idea.

BTW: 25 years ago our city was very deliberate in informing us that they are intentionally making the water slightly alkaline. We have naturally acid water, and it eats up the pipes. The city was mostly worried about eating solder and leaching lead. What I see here is a natural result of them adding literally truckloads of lime per day to the water supply.
 
I'm certainly no chemistry or water heater expert, but from what I've read it's calcium that forms from the heat in the water heater. I flush mine about every two or three months and get maybe 1/4 to half a cup of the crystals. I don't measure it so I don't really have an accurate measure of how much comes out and some escapes the bucket I drain the hose into.
 
Yeah, calcium makes sense. I didn't taste it, maybe next time.
 
A little further study shows that what we call "lime" has a high component of calcium. So, this is all making sense. I searched my municipal websites and found that they don't necessarily add lime by the truckload, as I jokingly mentioned earlier, but they do inject certain alkaline chemical solutions by the truckload, many of which have calcium as a component.
 
When we speak of "lime" in pipes or water heaters, we're mostly describing Calcium Carbonate (CaCO3) deposits which are mostly dissolved "rock" (or hardness - aka dissolved "lime-stone") which has precipitated out of solution due to changes in pH or other chemical reactions - such as concentration - within the water. Actual "lime" - essentially Calcium Oxide - CaO or slaked lime - aka Calcium Hydroxide - Ca(OH)2 doesn't usually hang around very long in solution as it loves to grab any available carbon dioxide (CO2) to convert the CaO to (wait for it) CaCO3 - aka lime-stone. The CaCO3 may remain in solution or it may precipitate out as (again) what we often call lime deposits. Of course there can be other compounds in municipal water which cause acidity but they too will typically combine with CaO, neutralizing them.

Lime is generally produced by heating lime-stone to several hundred degrees which drives off CO2 leaving CaO. Dumping lime into water does raise pH. - The lime does often combine with acidic molecules such as dissolved carbon dioxide (CO2.) So you get dissolved Calcium Carbonate either from the rocks in the aquifer or from the added lime.

One solution (pardon the expression) is to use a water softener which essentially substitutes sodium for calcium in water. The downside is added sodium which is not ideal for drinking as it adds sodium to the diet. Better to have an un-softened water line for drinking.

Returning you now...
 
Cool, Koolau. Thanks for the chemistry lesson.
 
just got a new waterheater at the most likely forever home & now that I know the history behind it...
I plan on doing yearly flushes, cant hurt...
 
And how are you flushing your water heater?

I do not want to move mine anyplace, so is it just connect a hose and let it run?
 
I do not want to move mine anyplace, so is it just connect a hose and let it run?
That's what I do. I put a bucket in the utility sink in the basement, zip tie a 3/4" hose to the faucet and put the hose in the bucket. This is to capture as much as I can of the crystals that come out and get some idea of how much is coming out. Some do "escape" from the bucket after it fills up with the turbulent water overflowing the bucket but I think most stay in. Can't be sure though.

I turn on the water for a minute or two, turn it off and drain the bucket to inspect what's left in the bottom. Rinse and repeat four to six times until the crystals remaining are very low.

Oh, and of course the hose is connected to the bottom drain on the water heater. If yours is plastic, get a brass one and be prepared to eventually have to replace the plastic one as the youtube videos warn that repeated operation of the plastic ones will wear them out. My water heater (AO Smith "Proline") came with a brass drain valve but I have a spare on hand anyway. They are not expensive.
 
Luckily, my heater is in the garage so I just put a hose on it. It has a brass valve which seems to work fine now.

TIP: get yourself a $2 plastic or brass hose cap before you do this. In the unfortunate event that your valve gets bollixed up, you can stick the cap on it to stop the flow and get your hot water working while you consider your options.
 
One more thing. While you are doing this and have the water off and the pressure released, it is time to inspect your expansion tank. Check the air pressure.

No everyone has these. They are required more and more in municipalities because they have put backflow preventers on the line at the meter. This means water builds pressure in your house as it heats, so it pushes against the bladder instead of your weak pipe joints. In the old days, it just pushed against the city water. Some municipalities don't require it. Well water systems are different, etc.

For most installations, that means balancing what you get from the city. That's usually 40 to 80 psi. My city provides water spot on at 60psi. And if you get water coming out of the schrader valve instead of a pressure reading, replace the expansion tank, it is blown.
 
Koolau, we have a water softener and a reverse osmosis system. Does the reverse osmosis system remove any of the added sodium?
 
Koolau, we have a water softener and a reverse osmosis system. Does the reverse osmosis system remove any of the added sodium?
I believe it does but do not know for certain. I'm sure there is lots of info on the net about RO units. Sorry, that's something I never learned much about.
 
Koolau, we have a water softener and a reverse osmosis system. Does the reverse osmosis system remove any of the added sodium?
The water softener exchanges sodium ions for calcium ions. An RO will remove some of the sodiums, as the reject water will be brackish.
 
Thanks Koolau & latexman. I did side-by-side taste tests this morning and could definitely taste the difference.
 
When I read your thread title my first thought was that the gel is the byproduct of the aluminum anode rod. We replaced our water heater last year and in my research I learned that the sacrificial anodes are generally made of magnesium or aluminum. With aluminum you get this gelatinous goo at the bottom of your tank that can gum up the flush spigot if left too long between flushing. Although your lime scenario makes sense too, just wanted to throw out this alternative cause.
 
When I read your thread title my first thought was that the gel is the byproduct of the aluminum anode rod. We replaced our water heater last year and in my research I learned that the sacrificial anodes are generally made of magnesium or aluminum. With aluminum you get this gelatinous goo at the bottom of your tank that can gum up the flush spigot if left too long between flushing. Although your lime scenario makes sense too, just wanted to throw out this alternative cause.
Yeah, absolutely. I thought it was the dip tube or anode. The anode may still be playing some role in the chemistry here (Koolua, comments?)

It wasn't until I saw the dried dust the next morning that I realized that *most* of what is coming out precipitated from the water. The amount was so large for 2 years, it had to be more than the anode, otherwise I'm toast. :)

BTW, I am considering replacing the anode at 5 years but I only have a few feet of clearance above. I'd have to completely take down the tank and put it on its side. Sounds like too much work.
 
They sell anodes that are separate rods linked together to allow them to be inserted into tight spaces. I have never used them, but it would be easier than moving the water heater to replace them.
 
They sell anodes that are separate rods linked together to allow them to be inserted into tight spaces. I have never used them, but it would be easier than moving the water heater to replace them.
I saw those, but for the first time, how do I get the old one out?

Lift and cut into sausage links maybe?
 
I assume that if your old one is really worn, then you should be able to snap/break/cut it fairly easily.

It is possible to check the old one. Simply turn off the water supply, relieve any pressure, maybe drain some water, but not drain the entire tank. Then undo the old one at the top and pull it up to get a look at it.

Might be worth doing that first anyway to verify the issue.
 
I saw those, but for the first time, how do I get the old one out?

Lift and cut into sausage links maybe?
Exactly. There are many, many youtube videos on just that issue. Cut it into pieces as you draw the old one out. And if you drop it inside the tank, that's not an issue either, it'll just lay in the bottom of the tank and won't hurt anything. Well, on a gas heater anyway, I'm not sure about an electric one.

This is an example of one of the "sausage link" anode rods. This one is magnesium but they make them in aluminum too.

To get the anode rod loosened it's okay to use an impact wrench. The maker of my water heater, A.O. Smith, recommends using an impact wrench. Some people think that will cause bad things to happen because the inside of the tank is "glass lined". Well, it is a ceramic, but it's not glass and loosening the anode with an impact wrench won't bother it a bit.
 
Some people think that will cause bad things to happen because the inside of the tank is "glass lined". Well, it is a ceramic, but it's not glass and loosening the anode with an impact wrench won't bother it a bit.

So, it's not like the Thermoses from the 60's? Drop it once and it's 1,000,000 pieces inside. :facepalm:

I should drain my heater some.
 
I don't have an impact wrench, but I have discovered that rapid taps with a persuader bar can work wonders.

Here's what I'm thinking. I need to at least make sure the anode loosens easily, soon. And then do that in my yearly schedule.

This is new to me. My dad was a plumber and he was of the camp: "Don't mess with it if it hasn't been touched." This is not bad advice. However, I do believe that messing with it yearly for draining and anode maintenance is not a terrible idea. I'm going to try that, now that I have reached the tender age of 60. Maybe I'll get my WH to last until I ... "don't care."
 
When we speak of "lime" in pipes or water heaters, we're mostly describing Calcium Carbonate (CaCO3) deposits which are mostly dissolved "rock" (or hardness - aka dissolved "lime-stone") which has precipitated out of solution due to changes in pH or other chemical reactions - such as concentration - within the water. Actual "lime" - essentially Calcium Oxide - CaO or slaked lime - aka Calcium Hydroxide - Ca(OH)2 doesn't usually hang around very long in solution as it loves to grab any available carbon dioxide (CO2) to convert the CaO to (wait for it) CaCO3 - aka lime-stone. The CaCO3 may remain in solution or it may precipitate out as (again) what we often call lime deposits. Of course there can be other compounds in municipal water which cause acidity but they too will typically combine with CaO, neutralizing them.

Lime is generally produced by heating lime-stone to several hundred degrees which drives off CO2 leaving CaO. Dumping lime into water does raise pH. - The lime does often combine with acidic molecules such as dissolved carbon dioxide (CO2.) So you get dissolved Calcium Carbonate either from the rocks in the aquifer or from the added lime.

One solution (pardon the expression) is to use a water softener which essentially substitutes sodium for calcium in water. The downside is added sodium which is not ideal for drinking as it adds sodium to the diet. Better to have an un-softened water line for drinking.

Returning you now...
We have extremely hard water from the tap and have used a water softener since we moved to this house. It does wonders for washing, bathing and keeping fixtures clean. We don't drink it for the reason you mentioned opting for a RODI multi-stage filtration system ($200-$800 on Amazon, depending on your requirements). The reverse osmosis deionization works well and generates TDS 10 (down from 450-500 from the tap) which is perfect for cooking, drinking and the ice maker. It may take some getting used to (drinking near distilled water) but we get plenty of minerals and other thingies from our food.
 
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