This pertains to a Suburban water heater, specifically the anode rod threading. 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. Any help? —David B.
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.”
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.