The Tank › Need advice on anode rod
- February 18, 2010 at 12:46 pm #12931
I just had to replace two 40 gal heaters that are 8 years old because both started leaking at the same time! There was rust everywhere, on top of the unit, the bottom, even on the lower part of the skin, the insulation was sopping wet and I was able to scrape huge pieces of rust under that insulation from the tank. Obviously, something is wrong with what happened for both to leak simultaneously.
I have a water softener and I use NaCl pellets. The water hardness is around 50ppm. I think I need Mg anodes, however when I notified the plumbers when ordering the tanks, the supplier said they only carry Al anodes here in Texas. So now I am afraid the same thing will happen.
Should I replace the Al anodes or just inspect them once or twice a year? (The new heaters are State Select w/ 6 yr warranty)
Should I switch to KCl pellets in the water softener?
Do I need to increase the hardness in the water?February 18, 2010 at 6:10 pm #12932Randy SchuylerKeymaster
At least your hardness isn’t down to zero. We recommend 50-100 ppm. We don’t aluminum for the reasons mentioned on our Anodes page, but I never push people to replace, but leave it up to them. Aluminum might last a bit longer in softened water.
If you stay with sacrificial anodes, check them every year and change them when you can see six inches of exposed core wire.
Another possibility, however, is powered anodes. They have done very well in softened water, at least so far, and I’ve been selling them for three years. If you go that route, hang on to the factory anodes. Heaters are sometimes defective and break for reasons other than rust. You’d want to save the powered for the next tank and put the factory one back in before you requested a warranty replacement.
Randy SchuylerFebruary 18, 2010 at 9:06 pm #12933
Thanks for the advice. I will probably just check the anodes yearly.February 19, 2010 at 11:13 am #12935Larry WeingartenParticipant
Hello: I’m a little confused by the water hardness of 50 ppm. Is that the calcium hardness left in the water after softening? What’s the hardness before softening?
To mess with Randy’s numbers a bit, it should be 60 to 120 ppm of “hardness” left in the water after softening according to the National Association of Corrosion Engineers, (NACE). I’d soften a little less if possible as oversoftened water can have the anode down to a bare wire in six months 😯
Yours, LarryFebruary 19, 2010 at 11:39 am #12936
I tested the water this morning and it is actually 80 ppm after softening. I have not tested the water before softening. I will check that when I get home from work this afternoon.May 29, 2010 at 1:25 pm #13461mikef135Participant
The following is a post on the message boards from Gary at http://www.qualitywaterassociates.com in response to this thread as I am trying to get to the bottom of why my water heaters only last 3-4 years. The softeners he sells are setup to remove all the hardness (down to 0 gpg). If this doesn’t happen he claims the softener medium itself will start having problems requiring back to back regenerations to shock the system back to life so to speak (and that may not work always). I bought one of his systems 5 years ago (w/ Clack WS-1 valve) and the system itself has worked w/o issue. I pulled the anode rod on my gas water heater and it was basically a nub – not sure how long it was like that but the life on the 12 year Whirlpool gas heater unit was 4 years and 3 months. Would like to see a rebuttal to this from someone more qualified than myself. Also, will the powered anode survive in 0 GPG soft water? I don’t think I have a choice on that based on my particular softener. Gut feeling says I don’t have an electrical problem … no other electrical related issues in my home.
“He is selling a powered rod and is thinking softened water is causing problems with water heaters when much more likely is a glass lining problem. Stray electrical currents can’t get through glass lining, period. And as long as the glass lining is intact, the steel of the tank can’t rust. By design the stray currents are supposed to eat up the rod rather than other metal that the water is in contact with.
The guys that go on about soft water being the cause are misapplying the Langlier Index. That index was invented for cement water pipe with asbestos fiber reinforcement to see if the water quality (naturally soft, aggressive) would erode (dissolve) the cement freeing the asbestos fibers to enter the water stream; that is a serious health problem. They want a hard water scale build up on exposed metal to protect the metal by isolating it from the water; if the glass lining is intact that can’t happen.
If you are eating up anode rods quickly, you have an electrical problem somewhere because ion exchanged soft water is not aggressive or corrosive anymore than the raw water is. Get an electrician to check the grounds on the house and the water heater and check for stray voltage/current due to TV, alarms, phone etc. etc. grounds on the metal water pipes. The jumper you have at the softener might not be making good contact.
The 0 soft they talk about is 0 gpg. Calcium hardness is not total hardness (magnesium must be included) and the 0 gpg is of total hardness, not just calcium hardness.
Again, most water heater failures are caused by electrical problems using up the sacrificial rod much faster than ‘normal’ and then the stray currents eating other metal parts. And the quality and application of the glass lining dictates how long the heater will last. Tanks also rust from the outside in.”May 30, 2010 at 5:04 am #13462Larry WeingartenParticipant
Please have a look at: http://www.hotwater.com/bulletin/tcb2.html . It’s good to look at one’s source of information and wonder if there could be a bias. My bias comes from having worked on thousands of heaters and seeing the effects of different waters. Also, I try to keep up on past and current research. The National Association of Corrosion Engineers and American Water Works Association provide good information.
Yours, LarryMay 30, 2010 at 12:24 pm #13463mikef135Participant
Thanks for the link. Confirms my findings at least.
I believe I see the other side of this issue to from the water softener perspective. If you don’t soften down to 0 then hardness is left in the resin and over time you create a landfill problem with the softener rather than the water heater. Your thoughts?
Anyhow, seriously debating your powered anode rod for recessed heaters. I have a Whirlpool heater. While the old unit was being pulled I dug out all the packed insulation around the anode hex head so it will be easy to get out. I tested removing the head on the old unit with an impact wrench and it came out just fine.
Is this powered anode unit a good match with my softener that is taking out all the hardness?
-MikeJune 3, 2010 at 1:35 pm #13487
Sorry for the late reply. I did check my water hardness before the softener and to my surprise it was 100 ppm. (In my defense, I moved to this house that had the water softener so I just assumed the water was hard.) So I turned off my softener and diverted the flow from it completely.
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