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Unstopping Clogged Drains, Toilets, and Sewers

Here are easy-to-follow instructions on how to unstop clogged drains, toilets and sewers. Read these instructions carefully before undertaking these jobs.

If any part of the instructions is unclear, call or visit your retailer and ask for further information.


  • If the drain is sluggish but not completely clogged, turn on the hot water tap for 5 to 10 minutes. This sometimes opens the drain.
  • If running hot water does not open the sluggish drain, try an environmentally safe chemical drain opener. Such cleaners are available in several forms, and they are made primarily from caustic soda with bauxite and other ingredients. Read the label on the drain cleaner and follow manufacturer's instructions.
  • After using any chemical cleaner, flush it from the drain pipes by allowing hot water to run for at least 10 minutes.


  • In some cases, using a simple suction cup will open a clogged sink drain.
  • First, remove the basket strainer from the drain (see image).
  • Run hot water until it stands about 2" deep in the sink.
  • Take a suction cup plunger and pump it up and down directly over the clogged drain. The water in the sink provides a seal. If the suction cup does not clear the drain in a few minutes, you will probably be forced to remove some of the pipes to get the job done.
  • If you cannot open the drain with the suction cup, set a pail underneath the sink trap and remove the cleanout plug and washer (see image below). If the drain is only slightly clogged, a few quick probes with a screwdriver may solve the problem.
  • If the screwdriver doesn't open it, use a snake or drain auger through the pipe. A drain auger works best if you rotate it, feed it in a short distance, and then rotate it again. This enables the drain auger to be inserted deeply into the pipe.
  • After the drain pipe is opened, replace the cleanout plug and washer. Run scalding water through the pipe to carry away any accumulations.
  • If the lavatory drain is only slightly clogged, try opening it by removing the drain stopper and probing for hair and other debris with a short piece of wire.
  • If this doesn't work, try a plunger. Since your lavatory drain has an overflow outlet, you'll need to plug it with tape or rags before using a plunger (see image). After plugging the overflow drain, use the plunger exactly as you would in opening an ordinary sink.
  • If the wire and plunger treatments do not work, use a sink auger or plumber's snake. You may be able to do this without removing the sink trap (see first image below).
  • If none of these efforts works, set a pail under the lavatory and remove the trap (see second image below). Cover the chrome nut with tape or a rag to prevent marring by the wrench.
  • Loosen the thumbscrew on the plumber's snake and move the handle back about 3' (see third image below). Insert the snake into the drainpipe, rotate the auger, feed it in, then rotate again. This allows you to drive the snake deeply into the drainpipe.
  • To unstop bathtub drains, try the running hot water, the plunger, or the chemical method. Remember to plug the overflow outlet before using a plunger.
  • If the chemical, the plunger, or the hot water treatments do not open the clogged drain, you'll need to remove the trap located under the tub. If the tub is on the first floor with crawl space or basement access to the pipes, this can be relatively easy.
  • In older homes this trap will be a drum trap (see image) which has a removable top. This top often becomes corroded and may be very difficult to remove. Apply penetrating oil to the top and let it set for a few minutes. Then use a large wrench to remove the top. If that fails, a hameer and punch may be necessary to do the job.
  • Tubs in newer homes usually have a tubular trap. The bottom portion of this trap can be removed by loosing the two large nuts that hold it in place. Prior to loosing these nuts hang a pail under the trap to catch any water that is in the trap.
  • After you have removed the trap or the cover check for debris in the trap itself and in the pipes leading to and from the trap. In tub drains clogs of hair and soap are quite commonplace. A pair of rubber gloves might be a good idea here.
  • After you have removed the clog and resealed the drain, run hot water through the drain for a few minutes. This will allow you to check the operation of the drain and to flush any remaining debris from the drain.


  • In most cases you can open a clogged toilet using a force ball-type plunger (first plunger in image). A regular suction cup plunger will seldom do the job (second plunger in image). A force ball-type plunger exerts a great deal more pressure for cleaning toilets than the regular type.
  • Be sure to have sufficient water in the toilet bowl when using the plunger.
  • If the plunger does not clear the clogged drain, use a closet auger (see image below). Start the auger or snake into the bowl and continue to crank it until it becomes tight. This cranking and pulling action will usually bring up the object that is causing the stoppage.
  • If the closet auger is not effective, use a small snake in the same way as described for opening lavatory drains.
  • If neither the plunger, the closet auger, nor the snake removes the obstruction, you may need to remove the toilet from the floor, turn it upside down, and force the obstruction out from the top or bottom.
  • If you must remove the toilet from the floor, use either a wax preformed O-ring or fresh plumber's putty in reseating the toilet.


  • In older construction there were three basic causes for clogged sewers. These were excessive mortar (see first image below) left at soil pipe joints, roots (see second image below) from trees and plants and broken pipes.
  • In both new and old construction, broken pipes (see third image below) allow foreign matter to enter the drainage system. This can often cause clogging.
  • Clogged sewers in newer construction are often limited to broken pipes and poor design or construction. Using the wrong fittings during construction or allowing too little slope in the drain run can cause the drain to become clogged.
  • To open a clogged sewer, set a container just underneath the cleanout plug (see fourth image below). Loosen the plug just enough to permit water and waste to flow into the container.
  • When all the water and waste have drained out, remove the plug and insert a cleanout tape.
  • Rotate the reel clockwise as you unroll it, and push the tape forward into the sewer pipes.
Closet AugerSuction Cup Plunger
Force Ball PlungerPenetrating Oil
O-Rings-Assorted SizesWork Gloves
HammerPlumbing Wrenches
Chemical Drain CleanerPlumber's Snake or Drain Auger
Graphite PackingPlastic or Galvanized Pail
Hand CleanerPunch or Cold Chisel
HacksawSewer Cleanout Tape

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Check your state and local codes before starting any project. Follow all safety precautions. Information in this document has been furnished by the North American Retail Hardware Association (NRHA) and associated contributors. Every effort has been made to ensure accuracy and safety. Neither NRHA, any contributor nor the retailer can be held responsible for damages or injuries resulting from the use of the information in this document.

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