Drain cleaning: what to know

What the job involves, what changes the price, and what to ask a pro.

What drain cleaning is

Drain cleaning clears a clog from a sink, tub, shower or main line so water moves freely again. People call when water sits in a fixture, a drain gurgles, or a slow drain has turned into a full stop.

Signs you need it

  • Water in a tub or shower stands for minutes before it drains, and the level rises when you run the sink
  • Two or more fixtures back up at the same time, which points to the branch or main line instead of one trap
  • Gurgling from the toilet or a floor drain when you run water somewhere else in the house
  • Clogs return within a few weeks after a hot water flush or a plunger, which means the blockage is deeper in the line
  • A sewer smell from a drain that is not used often, such as a basement floor drain or a guest tub

What the pro does

  • Ask which fixtures are slow and check the trap and the stopper or strainer for hair, soap and grease
  • Run a drain cable machine through the cleanout or the fixture, using a cutter head to break hair and root mats
  • Use a water jet when the line has grease or scale build-up, since a cable can punch a hole through the clog and leave the coating on the wall
  • Run water through the line to confirm the flow is steady and check the trap nuts for leaks
  • Explain the likely cause, such as grease in the kitchen line or roots in the main, and whether a camera check is needed to confirm it

What changes the price

Every job is different, so we do not publish prices. These are the things that move the quote up or down.

  • Whether the clog is at one fixture or on a branch or main line
  • Access to the cleanout, or whether a trap, wall or floor has to be opened to reach the blockage
  • The cause: hair and soap, grease, roots and foreign objects each need different tools
  • Whether a water jet is needed instead of a cable
  • Pipe condition, since old cast iron or clay can need several passes and can hold a clog in a low spot
  • Whether a camera inspection is added to confirm the cause

What a written quote should spell out

  • Which lines will be cleared and whether the main is part of the scope
  • Method used: cable, water jet, or both, and the cleanout or access point
  • Whether a camera inspection is included or quoted separately
  • What happens if the blockage is past the cable's reach or the line is damaged
  • Whether any access work, such as removing a trap or opening a wall, is included

Questions to ask before you hire

  • Will you run a camera down the line to find the real cause, or only clear the clog?
  • Is a water jet included, and when do you recommend one over a cable?
  • If the clog is in the main, where does the cable go and how far can it reach from the cleanout?
  • Will you check the trap, vent and cleanout for damage after clearing?
  • Can I see the camera footage if one is run?
  • What do you recommend to keep this line from clogging again, based on what you find?

Red flags

  • Pro pours caustic chemical into the line without asking what is blocked, since it can damage old pipe and splash back on the worker
  • Quote that says only 'unclog drain' with no line, method or cause named
  • Pro who clears one fixture and does not check whether the clog is in the main, which means the problem comes back
  • Pro who wants to open a wall before trying the cleanout, the trap or the fixture stopper

What you can do yourself

A homeowner can clear a single slow sink or tub with a hand plunger, a small hand auger, or by pulling and cleaning the stopper and trap. Call a pro if more than one fixture backs up, if water rises in the lowest drain, or if the clog returns within days, since those point to the branch or main line.

Licenses and permits

Drain cleaning on building drains is commonly done by licensed plumbers, and some areas require a license even for simple clearing. Check with your state or local licensing agency to confirm what applies to the work where you live.

Drain cleaning questions

How do I know if the clog is in the main line?

If two or more fixtures back up together, especially the lowest tub or floor drain, the clog is usually in the branch or main line. A single slow sink usually sits in its own trap and short branch.

Are chemical drain cleaners safe to use first?

Caustic cleaners can damage old or metal pipe, and the standing liquid can burn skin and eyes if a pro has to open the trap. Tell the pro what was used before work starts.

Why does the drain clog again soon after cleaning?

A cable often cuts a hole through the clog and leaves grease or a root mat on the pipe wall. A water jet or camera check shows whether the line needs more than one clearing.

Do I need to be home for drain cleaning?

Usually not, but someone needs to give access to the fixture or cleanout and remove any hair catcher or cover ahead of time.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

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