A threaded 3 inch cast iron cleanout plug in my toilet sewer line has deteriorated. I bought a plastic threaded replacement plug for it.

Can I just screw it in as is, or do I need to use something like Teflon tape or another type of sealant on the threads to prevent future leakage?

Thank you for your help.

Yes, you can screw it in as is. However, I suggest you put teflon tape over the threads. That way you make sure no sewer gases will be escaping into your bathroom


Hope that helps

Milo

You can use Teflon tape or plumber's grease... both work fine.

However, a 3" cast iron plug is usually not the same size as a 3" PVC plug, so be prepared, and if that is indeed your case in the end, you can purchase a 3" LEAD FIT ALL plug at a local plumbing supply store. Here, you grease the threads of the lead fit all plug and you use a hammer to tap the plug into the threads of the cleanout while you spin the plug... effectively cutting new, deeper threads into the lead plug.

Good luck.

Mark