a cast iron cleanout plug Home › Forums › Public Forums › Drainage & Sewerage › a cast iron cleanout plug This topic has 1 reply, 2 voices, and was last updated 24 years, 5 months ago by SylvanLMP. Viewing 1 reply thread Author Posts 1 Jun 2000 at 4:08 pm #278552 MasterPlumbersKeymaster i have a 1’1/2 comby with a cleanout,made out of cast iron and the plug just won’t come off so that i can clear the draini’ve tried heating it but it will not blugeany suggestions? 2 Jun 2000 at 12:49 am #298747 SylvanLMPParticipant Chop into the threads (use a chisel) THEN replace the CO plug with a new one with Teflon on the threads. Using heat (flame) is a FANTASTIC way of blowing yourself out of the picture. THINK of sewer gases HUH Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In