How to unclog a bathtub drain – 5 simple steps to swerve slow emptying

Trying to work out how to unclog a bathtub drain? Get that water moving again with our expert advice

chubby bathtub and chequered floor tiles
(Image credit: BC Designs/Darren Chung)

Blocked bathtub drains are a common issue that few households escape, particularly when there are long-haired people in residence. Plumbers take time and money, so it’s only natural that you might prefer to learn how to unclog a bathtub drain yourself. 

Hair is by far the worst bathtub drain-clogging offender, alongside 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 is likely to 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. 

This guide will tell you how to unclog a bathtub drain in simple, expert steps; you can take similar steps to unclog a shower drain.

How to unclog a bathtub drain

Prevention is often better than cure. ‘If you find your bathtub is constantly getting clogged, then make a few changes to stop it happening again,’ says David Cruz, plumbing expert at MyJobQuote (opens in new tab). ‘A simple strainer will prevent hair clogging the drain. And regular drain cleaning with a ready-made cleaner or even just hot water can help keep soap residue at bay.’ 

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. Here’s how to unclog a bathtub in five steps – we’ve ordered them by ease, so work through step-by-step until your bath empties in a timely manner. 

You will need:

1. Remove obvious obstructions

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 will need to remove it to gain better access to the drain. The majority screw off, but some may require a screwdriver to pop the drain stopper. 

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, small tongs or a wire coat hanger to drag them free.  

2. Boil the blockage away

Assuming there is no standing water in your bath, the next easiest solution for unclogging a bathtub is the good old boiling water trick. ‘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 activate it and help get things moving,’ explains Chris Wootton, Managing Director, of cleaning service Poppies (opens in new tab).  

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

3. Use a plunger

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 face cloth or large slab of putty (like Blu Tack).  

‘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 (unclogging a toilet requires a different size 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 (opens in new tab). ‘Repeat this a few times until, with luck, the blockage is gone.’

4. Add baking soda and vinegar

Cleaning with vinegar and baking soda is a good way to clear a blockage in a bathtub drain. 

‘Baking soda and white vinegar are a great home remedy for unclogging a bathtub drain. Pour some bicarbonate soda into the drain and let it sit for 15 minutes before pouring white vinegar down the drain,’ says Trinity Owhe, Design Expert, Victorian Plumbing. 

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

5. Invest in a plumber's snake 

If your blockage is still refusing to budge, it’s time to tool up! There are a 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 (opens in new tab).  

bath drain with hair snake and pipe cleaner

(Image credit: Future PLC/Linda Clayton)

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.  

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.