Building a dam around a water heater FAQ

To save you from reading all my research on this, this section, I'll tell you that I feel like I'm in the Twilight Zone. No evidence so far of anybody making vinyl lined tanks, whether they called them glass-lined or not.

It's conceivable the one I took apart was not labeled glass-lined. I might have thought it was because the one I had just installed had that label. Hmmm. If I'd known that some ARE glass lined, I wouldn't have been so willing to accept the one with the crushed top and the input pipe being no longer perfectly vertical. I figured that couldn't hurt vinyl but it could hurt glass.

Could the glass chip and get into my hot water? I'd hate to get the glass in my washcloth and then try to wash myself. Once in college I pulled a piece of paper out of my wastebasket to make a paper wad for throwing, and I'd forgotten that a thermometer in a broken glass tube was in the trash and I cut up my hands wadding the paper. Not badly but in several places.

Sears is out of business I think, so that will make it harder***, but I plan to look. But if I do find the very same model, it might merely say, "glass-lined" with no description of what that means. AFAICR, that's what it said when I first bought one or more of them.

Den't read this. Only included because it shows that AOSmith was/is one of the makers of Sears WHs.

So I used another tack and looked for glass-lined, and by golly, one is by AOSmith:

There there are 114 under the home-depot section glass-lined tank:

But I found Are A. O. Smith water heaters glass lined? A. O. Smith changed the water heater market over 80 years ago by introducing the glass-lined tank for all tank water heaters. By lining the inside of the water heater with glass, heat stays within the tank and protects the steel exterior from rusting and becoming a safety risk.

Yes, but it didn't have the strands that fiberglass has. It was slightly hard to separate from the metal case around it, because it was pretty stiff and had been next to the metal for years and it was hard to find a place to grab it, and I think I had to pry it away, but when I did, it bent like a thick rubber mat meant to stand on at a work station. It was milky to clear in color. That is, iirc you could see a millimeter or two into it. I should have saved some of it but for once, I didn't. (After I got it in two pieces and brought it upstairs, I cut it in a lot of pieces to throw away with the weekly trash pickup, sort of like in a Hitchcock episode.)

Not in my case. Not glazed at all.

Yes, a good one.

Because the ceiling is not high enough, I guess.

BTW, I noted the complaints from 3, maybe 4 people about my replying to more than one person at once. I know Usenet is not email but for lack of a Usenet authority, I checked with the greatest email sage I know and she, Katrina, said it was fine. That that was how it was supposed to wrok.

Maybe this will help. I'm not replying to specific people, so the attribution line at the top doesn't reflect that I am. Rather, I'm giving my opinions or facts and I put some of my lines after lines from the preceding post (including lines from prior posts quoted in the preceding post) so that if my meaning is not clear, readers can use the quoted lines to tell what I'm talking about**, not to tell who I am talking to. I'm talking TO everyone with every line.

So I hope you will just read my words and not worry about who said whatever I'm replying to. Except for a couple trolls, I regard everyone here with the same respect and even when I disagree I don't mean it to be personal.

So what is a grey water heater? I thought gray water was used for irrigation or industrial cooling, not in homes and not for bathing. Ewwww.

I guess I visited the Twilight Zone.

They apparently put something heavy on the carton holding my current WH. I didn't notice this until I opened the carton after I brought it home, and the input or output pipe was not perfectly vertical. I pushed it a little to solder in the house pipes. Is the glass liner broken? Will pieces chip off and come out my sink or bathtub?

Whew! Although I don't know. I can imagine little chips almost floating and being carried along by the current.

SPECIFIC GRAVITY of glass 2.4 - 2.8, heavier than I thought. I guess you're right and I'm safe.

It's not like I'd change the WH if you said it was going to cut me. I'm too cheap, lazy, and optimistic to do that. After all, much of the hot water is used in the washing machine, must of the rest never touches me and much of the rest just bounces off when I wash my hands. And if the chips chip off when I'm not using the hot water, which is 95% of the time, that would give them plenty of time to reach the bottom before the current carried them away.

But now I have to cut open the current WH when it wears out, partly to see if the glass has chipped, if it's lying in the bottom like you say it will, and if it's really glass, or if I'm still in the Twilight Zone and it's vinyl again. I'll post again in about 10 years after I cut it open. Be sure to be here.

I never flush my tank and when I cut it open the last time there was just about 3 or 4 tablespoons of little gravel.

Here, I'll save you the trouble. Here's a video by Matt Risinger where he cut open some water heaters.

I had not realized what vitreous glass was until I looked it up, I was visualizing something like window glass or a coke bottle. Turns out this is recycled glass crushed into fine sand and baked on, pretty close to something like porcelain on a cast iron sink. It is supposed to protect the steel from corrosion but no coating is 100% even new, and of course the attack happens at those small defects so it is concentrated. That's why you need the anode.

It would be nice if there were an easy way to test the anode.

They make flexible (actually "sectional") anode rods to eliminate the need to "uninstall" the existing water heater (in many cases).

Another common place for a leak is through the pressure relief valve. You can cap that too, but that is generally considered to be a really, really bad idea.

Water can leak from all sorts of places. Once the steel tank begins to rust (the glass lining doesn't last forever) a pinhole can happen anywhere. Most times the water will drip (appear) at the bottom, but that's because gravity sucks. You don't know how far up the actual hole is.

I once had a gas WH that appeared to be leaking from the flue pipe *above* the WH. A short time after the WH has recovered, water would begin to drip from that cone shaped thing at the bottom of the flue pipe, right above the WH. You could see water dripping from the flue and you could hear it sizzle as it dripped down into the center of the WH. Sometimes there would be a puddle on the top of the WH.

What I finally determined was that the WH heater had develop a leak and water was getting into the *internal* flue pipe. The flue gases were carrying the mist up into the external flue, causing condensation. Once the flue started to cool, the water began to drip down, because, as I said earlier, gravity sucks.

In theory a tank should not begin to rust until the anode is consumed.

So if you had a way to measure the voltage difference, or if you just made a guess based on age and experience, you could have several plugged holes in the top of the tank, and just insert another flexible or short anode periodically. Maybe every 5 - 10 years. The heaters and thermostats can be replaced as needed.

I suspect an anode fails either by being consumed, or by being coated with scale.

Since the anode is electrically connected to the steel, I don't see an easy way to measure if it's working or not. With impressed current you can do the "instant off" test.

Both of my WH's lasted over 15 years, well beyond the stated warranty, so I'm satisfied with their lifespan. Since I install my own, the only cost is the WH and associated parts. I'm OK with that.

Both gas so no "heaters" to replace, unless I needed to replace the burner, although burners going bad is vanishingly rare, at least in my experience. Actually never happened.

My current gas water heater was installed Nov 1995. I've replaced the thermopile once. Reliance brand, made in Ohio.

That sounds like a very good idea. I only have less than a foot of space above mine. Is there something showing on the top that shows where I'm supposed to replace an anode rod?

An Amazon add for an expensive one $15p, says "Corro-Protec™ Powered Anode Rod for Water Heater, 20-Year Warranty, Eliminates Rotten Egg/Sulfur Smell within 24 hours, Stops Corrosion and Reduces Limescale, Electrical Anode Rod Made of Titanium "

I would think the cheap ones do all the same things, except maybe don't last 20 years.

That sounds like a very good idea. I only have less than a foot of space above mine. Is there something showing on the top that shows where I'm supposed to replace an anode rod?

An Amazon add for an expensive one $15p, says "Corro-Protec™ Powered Anode Rod for Water Heater, 20-Year Warranty, Eliminates Rotten Egg/Sulfur Smell within 24 hours, Stops Corrosion and Reduces Limescale, Electrical Anode Rod Made of Titanium "

I would think the cheap ones do all the same things, except maybe don't last 20 years.

I'm skeptical about the powered anode on water heaters. They should work, but there's no easy way for a homeowner to know if they've failed or been set correctly.

When I was in public works we used powered corrosion protection, called impressed current, for gas lines. But we dedicated an electrician to doing the annual instant on tests in each area. You want the right amount of current. Either too much or too little is bad.

In a water heater they should protect against corrosion. I don't see how they could affect scale or bacteria though.

$149, not $15p. ;-)

Though there is one for 90 dollars, for tanks up to 89 gallons, complete with power supply (a wall wart.)

uh huh. okay.

Thanks. Maybe I'll skip the powered one.