How to Locate Your Sewer Cleanout in Case of Emergency (2024)

Equipment / Tools

Materials

Locating Indoor Drain Cleanouts

1. Follow the Drainage Pipes to the Main Sewage Line

   The drainage pipes inside the home run to every sink, toilet, and water-reliant appliance, like the dishwasher and washing machine, so finding a drainage pipe shouldn't be too difficult. Look for black or white ABS, cast iron, copper, or bronze drainage pipes that lead away from the sink, toilet, or appliance. You can typically find the main sewage line by following these drainage pipes.

2. Look for a T- or Y-Shaped Pipe Fitting With a Cap or Plug

   When the drain cleanout is installed indoors, it can typically be found on the main sewage line, just before the main line meets the home's foundation.

   • The drain cleanout will be on a T- or Y-shaped pipe fitting with a threaded plug and a square nut. The nut may also be covered by a plastic cap.
   • The drain cleanout isn't always installed on the main line. Some homes may have alternate access points to the sewage system. Instead, look for a black or white pipe with a threaded plug and a square nut.

3. Check Bathrooms, Utility Rooms, and the Garage

   Inspect alternate locations around the home when it's not on the main sewer line. Use a flashlight to help see better in dimly lit areas.

   • The drain cleanout will often be close to a cluster of drainage pipes, like a full bathroom with drains for the sink, toilet, and shower. Inspect each bathroom in the home, looking for a capped black or white ABS plastic drain line.
   • Also, check the utility room or the garage.
   • Current or previous owners may have done renovations that hid the main drain cleanout. If your efforts to find it fail, contact a plumber to help locate it.

4. Test the Drain Cleanout Plug

   After finding the drain cleanout, it's a good idea to test the plug or end cap to ensure it opens.

   • Put on disposable gloves and use a pipe wrench or a large pair of Channellock pliers to grip the square nut on the drain cleanout plug.
   • Gradually begin turning the nut with the wrench, loosening it fully. Clean away any accumulated grime from the threads, then replace the plug.
   • In rare cases, the cleanout may be covered by an expandable plug that is loosened by turning a screw in the center of the plug.
   • Even more rarely, the cleanout fitting may be covered by a rubber bonnet and secured with pipe clamps.

   Warning

   Call a professional if you start to open the plug and see water or feel pressure under the cap. Pressure indicates a stoppage in the line. If you continue to open the plug, your drainage pit, yard, or house may fill with backed-up raw sewage.

Locating Outdoor Drain Cleanouts

1. Walk to the Septic Tank or Municipal Sewer Line

   Start at the septic tank location or municipal sewer line. The sewer line is indicated by the nearest maintenance hole or a curb with a large "S" stamped into the concrete.

2. Estimate the Direction of the Drainage Line

   The drain cleanout is usually located close to the home, in line with the septic tank or municipal system.

   • Septic systems: Walk back from the tank towards the home, looking for a plastic pipe vertically sticking up from the lawn or garden.
   • Municipal system: The actual drainage line is usually not visible, so trace a broad path through the yard to find the drain cleanout pipe. The pipe is typically black or white. sealed with a threaded plug with a square nut and may be labeled "S.C.O." or cleanout. Sometimes, this plug is covered with a plastic cap or a metal lid. Also, look around for objects or coverings for a 3-, 4-, or 6-inch pipe.

3. Move Lawn Decorations, Foliage, and Other Obstacles

   It may be accidentally or purposely covered or hidden if you still cannot locate the drain cleanout.

   • Obscured by lawn objects or foliage: Move any lawn decorations obscuring the yard outside of bathrooms, expanding the search area as you go. Foliage could obscure the cleanout. Overgrown grass can also be a problem, so mow the lawn to help make the search easier.
   • Buried in the yard: The sewer cleanout may be completely buried. Estimate where the drainage line is coming in and use a long screwdriver to penetrate about 1 inch into the ground, probing for the top of the pipe. This method is essentially trial and error, even with a good educated guess, and can be time-consuming. In this case, hiring a professional to locate the drain cleanout may be worth it.

4. Mark and Test the Drain Cleanout

   • After locating the drain cleanout, mark the location with a metal stake and a brightly colored flag, which will serve as a quick reference point in an emergency.
   • Test the drain cleanout plug to ensure it can be removed if necessary. Use a pipe wrench or a set of large Channellock pliers to unscrew the nut from the pipe slowly. The nut should thread out easily, but if you see water or feel pressure in the line, tighten the nut again and call a plumber to clear the clog.

How to Maintain Your Drain Cleanout

Most plumbers and professional sewer companies can clean main drain lines. Consider getting a sewer specialist to perform an annual inspection and cleaning. They can also check for tree roots that might interfere with buried sewer lines.

A homeowner can clean the main drain blockage only if they have training and specialized tools, such as a motorized drain auger.It is generally not recommended that DIYers attempt cleaning the line.