sacrificial anode -- I'm confused

[Doug Lassiter]

Hi -

I have a Whirlpool Flame-Lock 40 gallon gas water heater. It's about a year old and has a 12-year warranty. I realize that in a year or two I should be inspecting, and possibly replacing the sacrificial anode. But the installation instructions and use & care guide for the heater say little on how to do it. In particular, the instructions don't even say where it is! In fact, the instructions say that "each water heater contains at least one anode rod". NIce. Now maybe tell me how many

*mine* has?

Yes, I know that one kind of anode can be on the outlet, and another can be in a separate port at the top of the water heater with a hex head. But I don't know which I have, or if I have both. I also understand that a 12-year warranty (versus a 6-year warranty) may point to two such anodes. You would think that some documentation would cover this.

There are two ports on top of the water heater (in addition to the water inlet and outlet). One is filled with spray-in foam, and I'm reluctant to go digging that stuff out to see what is under it. Another has a plastic cap on it that is flush with the surface. (A little hard to get back there to see what is under that cap.) There is no *obvious* hex head sticking up anywhere.

It is quite perplexing that the support materials don't give this info, though I guess that Whirlpool has no incentive to tell me how to extend the life of the unit (though they do tell you how to drain and flush in some detail).

Can anyone give me some pointers here?

Thanks,

Doug

[hallerb]

a few questions, what did that tank cost you? are you prepared to replace it now if mucking with the anode causes a leak? is there cieling space to get a new anode in once you get it loose? how many other things could you be fixing on your home to extend or enhance its life? in 12 years its highly likely a new more efficent tank design will be available. do you know many tanks fill with crud decreasing thei gallon capacity long before they leak.

all of these should be considered before you get over ambitious maintaing a siple realitvely cheap appliance

[Nate Nagel]

I'd bet that a 12 year warranty tank has both a combo anode and a hex head anode. The only one that's likely practical to inspect is the hex head, but it should give you a good idea of what's going on inside.

see here for PM ideas...

I'd bet that the pry-off cap hides the hex head anode. I'd also bet that you'll find it's in good shape but it doesn't hurt to look. I also pulled one out of a water heater I had installed a year ago just because. What you're looking for is some evidence of corrosion on the anode, but not enough metal eaten away to expose significant amounts of the core wire.

nate

[Doug Lassiter]

Thanks. Makes sense that the hex head is probably under that plastic cap. Worth a look, though it requires climbing around. I did see the waterheaterrescue website, which is vastly more useful than anything else I've seen, but I was hoping to get something more specific about my own heater. That website is also very clear about how to evaluate the condition of the anode.

My understanding is that the combo one is accessible by removing the outlet line. That's feasible, but will take a little time to cool things down enough to do it. Also, the mechanical arrangement isn't obvious on that. Need to do some more reading on how combo anodes work.

The unit is a $500 one, and while yes, 12 years from now, I can spend another chunk of cash to get a new one, I would not mind seeing if it is easy to get it to last longer. As to filling up with lime, yes, that's a risk, but regular flushing actually does seem to do a pretty good job. My last (6-year warranty) heater lasted about seven years, and I never looked at the anode. I did flush it regularly, and when I removed it, the tank was leakeing from corrosion, the anode was crap, as it turned out, and there wasn't too much lime buildup. That's why I'm interested in anodes!

[Nate Nagel]

I don't see that it's a big deal to let a few gallons out the drain valve every year, and also check the anode. Only costs you a little time and maybe some pipe dope or tape. Also a new water heater isn't "cheap" at least by my standards, the tank alone would run 4-500 bucks, and install would probably be at least the same. Might as well save my money and keep an eye on it. I just replaced two anodes in some really old water heaters, primarily because one of them is a really expensive indirect solar deal that I just couldn't afford to replace.

nate

[Doug Lassiter]

Ah. I hadn't seen *that* particular page in the "rescue" site. Especially useful. But one must take pause with words like "Now the fun begins. On some tanks, the hex head of the anode is exposed and in sight, such as in this picture. On others, it's hidden sometimes under a sheetmetal top that's foamed into place."

So WHY can't Whirlpool just tell me where it is???

As it turns out, now that I've climbed up to have a look on the far side of the hot water closet, that plastic cap is glued down with some white material. Not at all easy to get out, and certainly not obvious what's underneath it, except for lot of that white stuff. There is also (hadn't seen it before I climbed up to look) a sheet metal section ~2x2 inch, of the top of the heater that has perf marks around it. In principle, it looks like it could get pried up.

I may just have to call the Whirlpool help line, where I'm afraid I'll get someone who doesn't have a clue about these anodes.

Doug

[Mark]

The best way to extend the life of the heater is to keep the temperature control set as low as you can and still take a warm enough shower.

Mark

[Nate Nagel]

Curious why you say that, I've never seen that addressed...

I'm (barely) old enough to remember when "standard" water heater temperature was 130F. Then people started recommending that you set it at 120 so as not to scald children/elderly etc. Then they started recommending that you set it back to 130F to prevent Legionella but install tempering valves at any fixtures where it would be likely that people could be touched by hot water.

I've just set my heater at 130F because I like a nice hot shower, don't particularly want to get Legionnaire's disease, and it seems to do a better job with dishes and clothes. I don't have any tempering valves... I know, living dangerously, you can all laugh at me if I do manage to burn myself. (I might change my tune if I ever have kids.)

nate

[dicko]

I wouldnt even worry about the outlet rod. All you need is one rod to be protected. If you pull the separate rod and its still in good shape, thats all you need to know. If its eaten up, you put a new one in, and again, you're good to go. The other rod may be gone or it may still be in good shape, you dont care.

Another point is that the outlet rod is an integral part of the outlet port. You wont find one of those at the big box stores.

The length of the warrenty is directly proportional to the size of the anode rods. If you have a 12 year warrenty and its only 2 years into its life, I think I'd wait a bit longer before trying to crack it open. Unless you have really agressive water, you should only be

1/6th of the way into the lifetime of the rod(s).

I am on a well and around here the first thing water heater installers do is remove the anode rod. I installed my own waterheater and didnt know this. I've never smelled such stinky hot water. Tried a low stink anode and it didnt help. Finally ended up removing the rod. The previous water heater had a 7 year warrenty and ended up lasting 13 years. I didnt look but I'm sure it didnt have a rod either. It didnt stink.

-dickm

[Erma1ina]

The "Installation Instructions and Use & Care Guide", page 28 shows the locations of the anode rods on your heater. Check it out at:

[Doug Lassiter]

Oh my. The guide I have has 27 pages! I saw this at the whirlpoolwaterheater site, but the front page was the same as what I had, so I just figured I already had the whole document. I can't understand what happened to my guide! Very screwy. The text does refer to the "Repair Parts Illustration", which had me puzzled.

I owe ya one. Thanks!

OK. That means that the sacrificial anode is hiding in the hole under the spray-on foam I was reluctant to excavate. Gotta get out the pick and shovel!

I guess that means there is one, not two? I've read that the high-year warranty heaters either have two of anodes, or one heavy gauge one. So I gather this is the latter.

Doug

[Mark F]

many folks around here have had to replace their tanks in less than

10 years, sometimes 5, and someone finally noticed that there was no water hammer cushioning device in their system; early fracturing of the tank / liner. Good for plumbers, bad for homeowners. Had to twist my contractor's arm quite hard to make him provide a catch pan / drain to the outside for the eventual failure of the tank. Idiots... /mark

[trader4]

I'd also second the advice that at 2 yrs, it's not worth checking the anode, unless you live in an area known for early tank failure. I would start checking at about 4 years. I've got a heater with a 10 yr warranty and it must be about 7 yrs old now. I checked the anode recently for second time and it's maybe 1/2 half gone.

The real question is whether replacing it makes any difference. I don't doubt that the sacrificial anode does head off corrosion. This is a well known concept. However, the question is whether the original anode is sufficient to get the heater into the range where other failure mechanisms become predominant and the tank will likely fail from one of those. If that's the case, then replacing the anode may not make a significant difference.

[Doug Lassiter]

That's good reasoning. My only data point is my previous tank which, when it failed a bit after after warranty, had a sacrificial anode that looked like it needed replacing.

Not clear if my water is hard on tanks in my area. Have not heard anything about that. My water is slightly alkaline, with some dissolved carbonate (we get lime deposits). Although I guess what counts is the oxygen content of the water. What characteristics of water are hard on tanks?

[hallerb]

tanks set to lower temperatures tend to last much longer, its also better when they are larger.

both of these minimize thermal stress on tanks