Why didnt my water heater's anode rod sacrifice itself ?

Dave Carpentier

Electric water heater on well water, fed from a softener.
So, when I last changed out my anode I wrote the date on the side of the tank.. and it said "Mag 2017".
5 years time got me feeling that there would be no rod left perhaps. Ordered a new magnesium one.
When I drew the rod out, I was kinda shocked to see it looking basically new.
I'll measure the diameter tomorrow and compare to spec, but it looks like there's nothing missing really.
Should I be thinking about pulling the elements out to see if theyre damaged instead ?
Do I just have good water conditions, and theres nothing wrong with this situation ?

Larry Weingarten

Hi, What sort of anode did you install? Is there a resistor in the head of it? If you bend the rod, does a hard scale flake off of it? I've seen anodes in softened water completely consumed in six months. For yours to be basically untouched after about five years tells me it's not working. Rheem puts a resistor in the head of their rods. Sometimes this slows the current flow enough to basically prevent the rod from working. Rheem anodes are flat on top of the hex head, while other magnesium rods have a weld bump on top in the center. Another thought... does your tank have a second anode? The existence of another rod could help explain things.

Yours, Larry

Dave Carpentier

This is a Bradford White tank (M280R8DS) and rod. I didnt see any other anode port or in the diagram.
In 90% sure it was a magnesium rod. I dont see any type of resistor area, but maybe internally ? The rod is part of the hot port.

Jamie Hall

Not all water is insanely corrosive, you know. If it's moderately hard, pH around 7 or a bit LESS, not softened... could be just the way it is.

hot_rod

Does BW have two anodes in some of their tanks?

Larry Weingarten

Hi, I looked up residential electric tanks on the BW site and only saw a single anode in the hot outlet. This type of rod can lose electrical contact between the magnesium and pipe nipple. A properly working magnesium anode should show a rough surface, with most metal loss at the ends. I never have anodes last longer than three years in softened water. Maybe consider installing a powered anode. It can be put into a replacement heater should this one fail.

Yours, Larry

Dave Carpentier

Sounding like I should pull the elements and looksee.

Larry Weingarten

Can't hurt. Also see if water drawn from the bottom of the tank is rusty.

Yours, Larry

Dave Carpentier

Just went out and looked over the back lawn area where the tank drained to. No rusty brown patch that I can find. When I used the same hose later on in the day to flush the house pipes (had just shocked the well) a bit of dark did come out. But I was also pushing air, which tends to clean out the piping innards a bit (got a small bit of dark in every point).

mattmia2

/here is the same thing on Larry's web site:
https://www.waterheaterrescue.com/products/powered-anodes-for-sale.html

I would also replace the drain with a full port ball valve if you haven't already so that you can effectively flush it.

Larry Weingarten

Hi @mattmia2 , I did teach the owner of that site, Randy a lot about hot water, but it’s his child and I have no financial interest in it. I’m more of a godfather 😉 He has good stuff and provides good support. Thanks for bringing up the right drain valve. It matters!

Yours, Larry

Dave Carpentier

Thanks for the link. Bookmarked.

The valve that comes with this tank is this ball valve.
Worth an upgrade ?

Larry Weingarten

Hi, I’d just compare the size of the opening in this valve and a full port ball valve. More flow has a good chance of carrying more sediment with it. What you have is much better than the normal plastic valves!

Yours, Larry

reggi

mattmia2 said:

/here is the same thing on Larry's web site: https://www.waterheaterrescue.com/products/powered-anodes-for-sale.html I would also replace the drain with a full port ball valve if you haven't already so that you can effectively flush it.

Psst . https://www.larryweingarten.com/  he's very modest 

george_42

I dropped my chanelock wrench and it hit the plastic drain valve and snapped it off and 50 gal hot water on the floor. the customer just happened to have huge pile of rags nearby and soaked up all the water before it could get to the finished basement area

Dave Carpentier

george_42 said:

... just happened to have huge pile of rags nearby and soaked up all the water before it could get to the finished basement area

Had a toilet seriously overflow once, only thing handy was the bath towels. I told the wife we could just launder them. So then we went shopping for new bath towels.