Seven plumbing and bathroom specialists have shared their preferred methods for clearing blocked drains, and they all agree on the same first step: pouring boiling water down the drain. This simple approach can help melt and loosen grease or scum that may be causing the blockage.
Boiling Water as the First Step
According to Andy Ellis, shower and bathroom specialist at Vidalux, boiling water is a straightforward yet powerful trick. "It can help fix drain clogs by melting and loosening any grease or scum that is in the pipes." Olivia Young, cleaning specialist at Astonish, offers identical guidance: "Start by pouring a kettle of boiling water down the drain to loosen residue."
Jess Thomas, managing director of Drainage Central, suggests a step-by-step method: "Fill your kettle with the maximum amount of water that it can hold and boil it. Slowly pour the water down the blocked drain in two to three stages, allowing a few seconds between each stage to give the water time to work. This can be repeated if needed, and adding washing-up liquid can help if you think that the blockage is caused by grease." A specialist from Plumbworld agreed: "One of the easiest cleaning hacks is to pour boiling water down the drain regularly to help dissolve grease."
Baking Soda and Vinegar
Six out of seven specialists also advocate for the combination of baking soda (or bicarbonate of soda) and white vinegar. James Roberts, director of Sanctuary Bathrooms, explains: "Using a solution of baking soda, vinegar, and water can easily unblock a bathroom sink," adding that "Vinegar's acidic nature enables it to dissolve dirt, grease, grime, and eliminate bacteria, making it an ideal cleaner for your bathroom."
Andy from Vidalux shares his approach: "My go-to hack is to pop in about four tablespoons of bicarbonate of soda, pour over roughly 250ml of white vinegar, let it fizz for five to 10 minutes, then flush it through with more boiling water." Olivia from Astonish echoes this technique: "Add half a cup of bicarbonate of soda, followed by half a cup of white vinegar, and let it fizz for around 10 minutes before flushing with more boiling water." Plumbworld also backs this strategy: "For more stubborn blockages, a natural mixture of baking soda followed by white vinegar can create a fizzing action that loosens debris."
Yet Jess from Drainage Central takes a different view, cautioning: "Leaving the two to sit in a drain for too long can cause them to harden and add to the blockage, and the acidity of vinegar may corrode older, metal pipes." Nevertheless, with six experts out of seven backing the method, it's evidently the go-to household remedy among plumbing professionals.
Prevention and Tools
Multiple specialists emphasised that tackling blockages is only part of the solution - stopping them happening in the first place is equally crucial. "The trick is to keep on top of them before they get bad," says Andy (Vidalux). "Once a month, pull out any hair or gunk you can see, then pour boiling water down to clear things through." Olivia (Astonish) advocates for bathroom drain covers: "A simple drain cover can catch hair before it causes problems." Plumbworld advises using strainers in kitchen sinks: "Regular use of drain strainers is also a great preventive measure to stop hair and food particles entering the pipes."
Should boiling water and bicarbonate of soda prove ineffective, physical intervention might be your most reliable option. Aspect's drainage engineer recommends a drain snake: "Carefully extract any obstructions you find using a drain snake, but be careful, as using too much pressure with a drain snake can cause damage to plastic pipes." Plumbworld continues: "If you need a tool, a manual drain snake or a plunger designed for sinks can help physically remove clogs without harsh chemicals." Jess from Drainage Central shares an economical do-it-yourself solution: "You can use a wire coat hanger to make a homemade drain snake to attempt to fish out the blockage or dislodge it. Bend the wire of the hanger into a hook, and insert this into the drain to remove clogs."
Caution with Chemical Cleaners
While many instinctively grab a bottle of caustic soda, professionals urge care. A drainage engineer at Aspect delivers a serious caution: "Caustic soda or 'lye' (sodium hydroxide) is a type of corrosive unblocker that can eat away at uPVC pipes when used excessively. Unless the crystals fully dissolve and clear the blockage right away, they can harden like cement - creating an additional blockage. You may then need to replace the pipe entirely."
Plumbworld advises steering clear of aggressive chemicals completely: "Enzyme-based drain cleaners like Bio-Clean or Green Gobbler break down organic matter safely without damaging your pipes. Avoid chemical-heavy cleaners where possible to protect your plumbing and the environment." Jess from Drainage Central echoes the sentiment that bleach should be a final option: "Bleach should be used as a last resort, as it can corrode some pipes."
Additional Tricks
Several specialists put forward other household remedies that might be worth exploring: Salt and lemon juice – Salt can act as a mild abrasive, while lemon juice adds acidity and freshness. Effervescent tablets – Fizzy indigestion tablets dropped into a drain with vinegar can mimic the bubbling action of baking soda and vinegar. Washing powder – Biological washing powder to break down fat and oil, followed by boiling water. Vodka or Coca-Cola – Vodka can help with maintenance (to kill bacteria and odours), while Coca-Cola can dislodge dirt if you’ve got nothing else to hand.
