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How to unclogg a Drain or Toilet

by Lorenz Prem
published on October 15 2009 6:17 pm

So you have a clog. Water is backing up into your toilet or sink. It's Thanksgiving day. You can't get a hold of a plumber. The prices the plumber charges are exorbitant. We have all been there. This post provides step by step instructions for unclogging the drain yourself; or at least do the simple stuff yourself before you call in the heavy guns.

The following steps should be done in order. They start with the simplest steps. The further you progress the more work you have to do and the messier the process gets.

1) Clean the strainer:

Some drains have a built in strainer. It's meant to keep large debris out of the drain. All strainers eventually clog. While this may not necessarily help you with toilets or your bathroom sink, it is the most common cause for outdoor drains to clog. Take the cover off and remove all the debris you can reach with your hand.

2) Next up, the plunger:

A plunger exerts alternating push and pull pressure on the obstruction in the pipe. It transmits the force to the clog through the water in the pipe. This is called hydraulic pressure. You push on the plunger, the plunger pushes on the water, the pressure travels through the water and pushes on the obstruction.

For the plunger to work properly, the pipe must be filled with water. If you have a slow draining clog, fill up the sink with enough water to slightly submerge the plunger. Push up and down repeatedly. You feel the plunger work through the handle. If you are successful, the water will evacuate the pipe in a sudden rush.

A plunger is an essential item in your household. You will need it eventually. It is inexpensive, and should work most of the time.

3) Chemicals:

There are a host of different products available that claim to dissolve "clogs" in your pipes. Simply pour them down the drain. After some time the pipes will be as good as new. I cannot comment on the effectiveness of these products, but I consider most of them snake oil. It's not necessary to pour dollars down the drain every time you have a clog without a guarantee of success. The other methods on this list are cheaper over the long run, and don't require a trip to the store.

On the other hand, if you want to chemicals to do all the work, this may be a good option for you. If they work as advertised, you need to pour them down the drain. Let us know what works for you.

4) Remove the Trap:

Sinks, toilets and most other drains have a U shaped trap somewhere near the drain's opening. This trap is meant to trap debris, just like its name suggest. Due to this function, the vast majority of clogs are caused by clogged traps.

Place a bucket under the trap. Remove the trap. Water will rush out of the sink into the bucket. If the sink is full, your bucket might not be large enough. Make sure it is before you take the trap off. If there is debris in the trap and relatively little water is coming from the pipe connected to the wall, you most likely had a clogged trap. Reinstall the trap and test the drain.

If a lot of water is coming from the wall, the clog is deeper in the pipe. Do not reinstall the trap. Move on to the next step. It's a lot easier to insert your drain snake or blow bag into the pipe in the wall without going through the trap.

5) Blow bag:

For outdoor drains or drains close to a garden hose you can use a blow bag. This device is attached to a garden hose. Insert the bag into the drain and turn the water on. The rush on incoming water will inflate the bag. The bag expands against the walls of the pipe effectively sealing it. The water then exits the bag and enters the new sealed section of the pipe. The pipe fills up. When it does the water pressure of your garden house is pushing against the clog. In most cases it will force the clog right out of the pipe.

Blog bags are dangerous to use in your house because they add water to the system. If your clog can resist the water pressure and the water has an alternate path, you might be blowing water into your sink only to have it come up the toilet. If you can't shut off the water fast enough you'll have a spill on top of your clog.

In most cases you can skip this step and move on the drain snake.

6) Drain snake:

Once you get to this step, things get messy. A drain auger is a long metal snake with a drill bit at its tip. It is inserted into a drain and advanced until it hits an obstruction. The entire snake is then spun around its center axis. This causes the drill head to burrow into the clog. The action either directly splits the clog, or the head catches the obstruction and allows you to pull it out of the pipe.

Using the auger is straight forward. Insert the tip into the drain and advance it. When you feel the snake not advancing anymore, you have either hit an obstruction or a bend the auger cannot get around without help. Lock the auger and spin it. You should feel the resistance slowly getting weaker. Advance the auger while spinning. Continue doing this until you feel no resistance anymore. Eventually you will hear a rush of water evacuating the pipe. Pull the auger back. Sometimes you might have to insert and pull back the auger repeatedly in order to break up a clog. In this case the clog is larger and requires several runs. You will have success with this method unless you are dealing with major obstruction such a collapsed pipe or tree roots.

7) Full-size drain auger

A drain auger is motorized drain snake. The snake is longer and can be spun with a lot more force. The principles behind it are the same as with the manual snake. The major advantage is that the drain auger can drive cutter heads that can cut roots in the pipes.

You can rent an auger from almost all rental places. Be careful. The forces involves are a lot stronger now. The situation you want to avoid is catching an obstruction the cutter head cannot cut rough; like the edge of a pipe segment. The head will lock and tension will build up along the snake. This tension will eventually release by causing the snake to violently lurch out of the drain and coiling in on itself. This can cause harm to the operator. Calling in the professionals at this point may be a wise decision for you.

8) Sewer jetter

If you have a pressure washer you can clean outdoor drains with a sewer jetter. The jetter is a long hose with a nozzle attached. The nozzle fires high pressure water forward and backward. The backward jets pull the hose into the pipe and clean the wall. The forward jet drills through any clogs.

The beauty of this system is that it simple and save. The snake advances itself. You actually have to hold it back. Commercial sewer trucks use this method. One drawback are the backward firing jets. Water will come out of the drain hole the snake is inserted into. This makes jetting impractical for indoor use.

Drain cleaning process


All homes should have a plunger and drain snake. These two inexpensive tools will allow you to clean almost all clog you are going to encounter yourself at only the onetime expense of buying the tools. By following the process you can avoid doing extra work. Most clogs are fixed using simple methods that are within reach of the home owner.

About the Author
"Lorenz is the founder of Hingmy. When he is not reviewing power tools or improving the site, he is building things in his workshop or playing hockey."