How to unclog a bathtub drain – 5 steps to stop slow emptying

Get that water moving again with these expert plumber's advice

A bathroom with a red and white chequered floor, a bath and sink
(Image credit: BC Designs / Darren Chung)

There are few tasks less appealing than unclogging a bathtub drain, but plumbers take time and money, and if you're short on either, it can be useful to pull on the rubber gloves and tackle it yourself.

We find that hair is the worst bathtub drain-clogging offender, followed by soap build-up and residue from bath oils and conditioner. However, if your bath has drained slowly ever since it was first installed, the issue will likely be down to the gradient of the pipework beneath or a more serious sewerage issue, which is when you’ll need to call in a professional.

Here, professional plumbers have shared their first-hand experience unclogging bathtub drains to help you stop the block and get water moving again. The best news? the same method can be used to unclog a shower drain and fix a clogged kitchen sink.

How to unclog a bathtub drain

Bathtub drains are prone to becoming clogged over time, especially if you have forgotten to empty it out for a week or so, begins David Cruz, plumbing expert at MyJobQuote. It happens to the best of us.

'If you find your bathtub is constantly getting clogged, however, then you might need to take some precautionary measures to keep water moving, he continues. ‘I find that a simple strainer will prevent hair from clogging the drain while making regular drain cleaning a lot easier.' It’s worth adopting the same tactics to avoid the need to unclog a sink, too.

If you are currently experiencing a blocked bathtub, the experts recommend simple bathroom cleaning tips are often the best way to deal with the problem.

You will need:

1. Remove obvious obstructions

Bath drain

(Image credit: Getty Images)

If you are lucky, you might find that the block is only on the surface level, and you can clear it by removing any obvious obstructions such as hair that has matted in the plughole.

If you have a traditional drain stopper on a chain, accessing the drain opening on your bathtub will be a breeze. However, most modern baths support some form of integrated drain stopper – be it pop-up, click-clack (a.k.a. toe-touch), or trip-lever. In this instance, you must remove it to gain better access to the drain. The majority screw off, but some may require a screwdriver to pop the drain stopper up and out of place.

Once you have taken the drain stopper out of the equation – and you may find a clog of hair/gunk comes with it – take a good look down the drain, using a torch if required. If you can see any obvious obstructions, use your fingers, a set of small tongs (we like these metal tongs, from Walmart), or a wire coat hanger to drag them free.

2. Boil the blockage away

white smeg kettle and toaster in kitchen with marble worktop and backspalsh and blue paneled walls

(Image credit: Smeg)

Assuming there is no standing water in your bath, the next easiest solution for unclogging a bathtub is the good old boiling water trick. ‘I have found that pouring boiling water down the drain will help you get to the areas that may be out of reach. Boiling water is ideal for clearing grease and soap that has stuck together – the heat will melt it away and help get things moving,’ explains Chris Wootton, Managing Director of cleaning service Poppies.

Just a liter or so of boiling water should suffice. Once it has cleared, try running the faucet to see if things are running smoothly. If not, it’s worth trying one more kettle full before moving to step three.

3. Use a plunger

Unclogging a sink with a plunger

(Image credit: Alamy)

Before using a plunger you will need to plug the bath’s overflow to create the necessary vacuum. Most overflow covers screw off, then you can simply plug the hole with a damp cleaning rag.

‘To execute the plunger technique properly, remove the drain stopper and fill the water up by a couple of inches. Take a sink plunger, not a toilet plunger, and place this directly over the drain before pumping it up and down a few times, taking pauses to see if the water begins to drain,’ says Trinity Owhe, Design Expert, Victorian Plumbing. ‘Repeat this a few times until, with luck, the blockage is gone.’

4. Add baking soda and vinegar

A container of baking soda beside a scrubbing brush

(Image credit: Getty Images)

'Cleaning with vinegar and cleaning with baking soda is a great home remedy for unclogging a bathtub drain,’ says Trinity Owhe, design expert, Victorian Plumbing. 'Pour some bicarbonate soda into the drain and let it sit for 15 minutes before pouring white vinegar down the drain.

‘The chemical reaction creates a strong foam-like substance that might dislodge any blockages and help neutralize unpleasant odors. Once the mixture stops fizzing be sure to rinse this away with water,’ she adds.

It's important to note that some experts say you shouldn't use vinegar and baking soda to unclog a drain. This is because in older homes, with metal pipework, acidic solutions like vinegar can accelerate the corrosion of pipes. If you're worried about damaging your own pipes, skip to step five.

5. Invest in a plumber's snake

bath drain with hair snake and pipe cleaner

(Image credit: Future PLC/Linda Clayton)

If your blockage is still refusing to budge, it’s time to tool up and learn how to use a drain snake or one of the range of tools readily available from hardware stores or online, designed to delve deeper into your drain. Plumber’s snakes, hair snakes, and long, flexible pipe cleaners are all brilliant for breaking through blockages further down the pipework underneath your bath.

‘A metal plumber’s snake that is about 9ft long is best for accessing any obstructions that can’t be removed by hand. They’re easy to use and very effective,’ says Ben Chalk, chartered construction manager, GIR Services.


What can I pour down my bathtub drain to unclog it?

Boiling water should be your first port of call. ‘Baking soda and vinegar are also great natural alternatives to chemical solutions. Pour a cup of baking soda down the drain, wait a few minutes for it to set, then pour a cup of white vinegar down the drain,’ advises Chris Wootton, managing director of cleaning service Poppies.

‘The mildly acidic solution should break down more severe clogs and following up by pouring boiling water down a few hours later should help clear any lingering debris. In the event this doesn’t work, you may need to resort to chemicals or unblocker – there are lots of reasonably priced and effective drain unblockers on the market,’ adds Chris.

Learning how to clean a bathtub drain will help prevent potential blockages from developing. It's one of the steps people with nice-smelling bathrooms take to remove bad odors and keep their bathtub drains flowing freely.

Linda Clayton

Linda graduated from university with a First in Journalism, Film and Broadcasting. Her career began on a trade title for the kitchen and bathroom industry, and she has worked for Homes & Gardens, and sister-brands Livingetc, Country Homes & Interiors and Ideal Home, since 2006, covering interiors topics, though kitchens and bathrooms are her specialism. 

With contributions from