Sunday, October 2, 2022


How to fix stripped threads on RV water heater anode

Hi Gary,
This pertains to the anode rod threading in a Suburban water heater. I cannot get the new anode rod threading to “catch” and screw in straight. It’s been getting more difficult every year but this year I’m stymied. Can you help me? —David B.

Hi David,
As will happen every now and again with repeated procedures, the female threads on the water heater tank fitting have likely become damaged or corroded over time. In the shop we use a tool called a “thread chaser.”

Thread chasers

Tool makers manufacturer both male and female thread chasers. Similar to a tap or a die (but different), thread chasers are designed specifically to clean and straighten existing threads only. To use a standard tap may actually remove portions of the existing threads as well as cut new threads — something to be avoided in a water heater tank fitting.

You’ll need a 3/4-inch NPT thread chaser since the replacement anode will likely have a tapered pipe thread. As a last resort, using a 3/4-inch NPT standard tap will work if you’re very careful. But the pros will use a correctly sized thread chaser.

Also, be sure to flush out the heater tank after chasing the threads in case any fragments of corrosion, metal or debris fell into the tank during your repair process. A couple wraps of thread sealing tape or an appropriate fresh water pipe joint compound on the first two or three threads of the new anode should have you back in business in no time.



Read more from Gary Bunzer at the See Gary’s videos about RV repair and maintenance.




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Dave stewart
5 years ago

hi Gary I like your advice I’ve been looking for a thread chaser like the one in the photograph I can’t seem to find one any help

George B.
5 years ago

You can likely replace the threads with a helicoil. If you don’t use them often to buy a kit is costly so seek out an automotive shop and find a helicoil that fits.

5 years ago

I bought a 3/4 inch black pipe nipple & use that as a thread chaser. Just be gentle & don’t force. I have a brass “toothbrush” that I use to cleanup threads & flush tank

John Sciortino
5 years ago

I have this problem too. My problem is not stripped threads, but correct alignment. They must be inserted straight into the hole. The long anode rod wants to tip down when inserted. I use a socket with a short extension when inserting the rod. With this setup I can tip the anode rod up a bit and insert it straight (level) into the hole. Since I turn it by hand, I can tell if it’s cross threaded or if it’s ok. After I know it’s good, then I tighten it with the ratchet.

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