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Products > Flexible Combo
Magnesium Anode Rod

Picture of flexible combo magnesium anode with 4-inch nipple


  • a .90-inch-diameter (25 percent more anode than what usually comes with a 6-year-warranty water heater, and 45 percent more than what comes with most flexible anodes) segmented combo magnesium anode rod (about 12 inches of overhead clearance needed). This anode is 48 inches long.
  • pipe-thread seal tape
  • service sticker
  • instructions

This kind of anode screws into the hot-water port and can either replace another combo rod or augment a hex-head anode. Fits all residential water heaters with 3/4-inch plumbing. Heaters of 75 gallons and more often have larger plumbing and if so, this anode won't work in them.

IMPORTANT! If you have an electric water heater made after April 2015 by A.O. Smith, State, Kenmore, Reliance, American, Maytag or Whirlpool, let us know because you'll need an anode with a pipe nipple longer than four inches.

Click here to learn how to read the label to know when a water heater was made.


  • The anode will keep your tank from rusting and breaking.
  • The tape will enable you to remove the anode in future to check it.
  • The sticker will help you remember when you installed it.


Pipe wrench. For further details, check out the Tools page and Know-How.

A Warning

If you buy one of these, don't play with it. It is possible you could pull the links apart. If so, you can't return it.


Merchandise in original condition can be returned within 120 days for a full refund of the purchase price, not including shipping. E-mail mail@waterheaterrescue.com for instructions and authorization.


The shopping cart generates an invoice and response, but we will give you delivery date and tracking information within a few days of your order by e-mail. We try to ship within one business day. If there is any hitch, we'll let you know immediately. If you hear nothing, consult your e-mail junk file. It's not uncommon for spam blockers to reroute our e-mails.


The products offered here are designed to make water heaters last longer, or solve specific problems. Installation is potentially do-it-yourself, but if you have the least doubt about your abilities, we suggest that you obtain expert help.

Remember also that if you have difficulties with installation, odds are that a professional or handyman will know a way to do it.

Shipping is by UPS within the contiguous United States. UPS does not deliver to post boxes. Allow up to about a week for delivery. Canada, Hawaii and Alaska are only served by Priority Mail and can use a post box.


If you contemplate adding an anode to a new tank, things have gotten complicated recently. The combo anode will not work in heaters made in 2005 or later by Rheem/Ruud/Richmond/GE.

Also, if there are two anodes in a tank, they need to be of the same metal. Otherwise, the magnesium rod will be consumed more rapidly in the presence of an aluminum one and you won't get as long a life. On the other hand, if the tank is five years old or more, having dissimilar metals is less of an issue, since the original one will likely be largely consumed.

All the lower-end heaters by A.O. Smith, American, State, Kenmore, Whirlpool and Maytag have aluminum anodes. We've thought about stocking aluminum combo rods, but we've preached against aluminum for 15 years and won't change now just to make a buck.

You still have the option of removing the aluminum hex anode that comes with the tank and installing two magnesium anodes. A plus is that ours are thicker than factory ones.

Also tell us the brand of your heater.

If you have any doubts about what you're ordering, be sure and e-mail your questions to us at mail@waterheaterrescue.com. We want you to order only what you need!


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