A slow drain is easy to ignore until it stops completely. Most clogs build up over time from grease, hair, soap and things that should never go down a drain. Knowing when to reach for the plunger and when to call a plumber saves time and pipes.
Sifixit is a free referral service. Call the number on this page and you will be connected with an independent plumbing provider where one serves your area. Calling costs nothing and you are never obliged to hire anyone.
Signs a drain needs cleaning
Watch for these signs before a slow drain becomes a blocked one.
- Water that drains slowly from a sink, tub or shower
- Gurgling sounds from drains or toilets
- Bad smells from drains
- Water backing up in one drain when another is used
- Several drains slow at the same time
- Standing water in a floor drain
What to do right now
Do not pour chemical drain cleaners into a blocked drain. They can damage pipes and cause burns if a plumber later has to open the line.
- Stop running water into the blocked drain
- Try a plunger on a single slow sink or tub
- Remove hair from shower and tub drains
- If several drains are slow, stop using water and call a plumber
- If sewage comes up, keep away and call for help
- Call a plumber for stubborn clogs
What causes clogs
Grease and fat
Grease poured down kitchen sinks cools, hardens and traps food scraps.
Hair and soap
Hair binds with soap scum in bathroom drains.
Wipes and other items
Wipes, cotton and paper towels do not break down and block pipes, even if the label says flushable.
Tree roots
Roots can grow into older sewer pipes and cause blockages in the main line.
How plumbers clear drains
- The plumber finds where the clog is, in one fixture or the main line.
- A drain snake or auger breaks up or pulls out the blockage.
- Hydro jetting may be used to scour grease and roots from the pipe walls.
- A camera inspection can show what caused the clog and whether the pipe is damaged.
- The plumber tests the drain and explains how to prevent future clogs.
How to prevent clogs
- Wipe grease into the trash, not the sink
- Use strainers in sinks, tubs and showers
- Only flush toilet paper
- Run hot water after using the kitchen sink
- Have older sewer lines checked if clogs keep coming back
Questions to ask before you hire
- Is the clog in one drain or the main line?
- Will you use a snake, hydro jetting or both?
- Do you recommend a camera inspection?
- Do you charge by the hour or by the job?
- What warranty do you give if the clog comes back?
Frequently asked questions
Are chemical drain cleaners safe?
They can damage older pipes and are dangerous to handle. A plunger or a plumber’s snake is safer.
What is hydro jetting?
It uses a high pressure stream of water to clean the inside of pipes, removing grease, scale and roots.
Why do my drains keep clogging?
Repeated clogs can mean grease buildup, roots in the sewer line or a damaged pipe. A camera inspection can find the cause.
Should I call a plumber for a slow drain?
Try a plunger first for a single slow drain. If several drains are slow, or the clog returns, call a plumber.
Learn more
Our main plumbing guide covers the wider picture, including what affects the cost and when to call a professional.
Sifixit is a free referral service and does not provide home services. Calls may be answered by a partner call center or connected directly to independent local providers, who are solely responsible for their work, pricing, licensing and insurance.