How to Remove a Brass Cleanout Plug

Grip the square head on the top of the plug with a pipe wrench and turn the plug counterclockwise. In the absence of complications, such as corrosion, this is all you need to do to remove the plug. Use the longest wrench you have, because you'll probably need the leverage of its long handle to turn the plug.

Loosen the threads of a stuck plug by generously spraying it with spray lubricant and waiting 10 minutes for the lubricant to penetrate the threads. Spray a second application and wait another 10 minutes if needed.

Gain extra leverage for turning a stubborn plug by fitting a 2-foot length of 1-inch steel plumbing pipe around the handle of the wrench. Pull from the end of the pipe.

Use a hammer and chisel to loosen a stuck plug if you don't have enough clearance for a long wrench handle. Use a moderately sharp wood chisel you don't mind resharpening after removing the plug.

Hold the chisel blade against the edge of the plug and tilt the chisel to about a 45-degree angle. The head should be facing in the counterclockwise direction. Sharply tap the chisel with a hammer to jolt the plug loose. Keep tapping and turning the plug until it is loose enough to unscrew with a wrench. Cast iron can break under the impact of a hammer or chisel. If you use a chisel, keep the head entirely on the plug and off the rim of the pipe opening.