10 Best Heavy Duty Drain Cleaners And Unblockers in The UK

Last updated on 15/08/2025

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Best Choice

9.7

Exceptional

Spear & Jackson

Spear Jackson Heavy Duty Sink and Drain Unblocker Gel - Powerful Formula- Indoor and Outdoor, 5 l (Pack of 1)

Why We Love It

Effective on tough blockages.
Safe for all pipes.
Experienced, reputable brand.

Main Highlights

SPEAR & JACKSON CLEANING PRODUCTS: Since 1760 Spear and Jackson has been selling hand, garden, contractors, agricultural, landscaping and professional tools from its base in the city of Sheffield. Their range of cleaning products are made to target tough stains, grease, grim and fat. Their Heavy Duty Outdoor Drain Unblocker Gel is designed to clear any deposits that are blocking your sink, leaving it draining smoothly
SINK UNBLOCKER LIQUID GEL: Spear and Jackson's Heavy Duty Sink And Drain Unblocker comes in gel form and is designed to dissolve the fat, food, hair or soap residue build up that's blocking your sink. Their heavy duty sink and drain unblocker gel will instantly clear and dissolve the unwanted blockage, and with the sink freshener element of the gel, your sink will be look and smell brand new
BATHROOM & KITCHEN SINK UNBLOCKER: With no drain snake require, this product really couldn't be any easier to use. The gel will dissolve any build up that is causing a blockage in your sink or drain in 3 hours. Ideal for the kitchen or bathroom sink, however this Heavy Duty Sink & Drain Unblocker works on exterior drains just as well. In comparison to other drain cleaners and unblockers on the market, this product has a powerful formulation that achieves results in rapid speed
BATHROOM CLEANING PRODUCTS: Spear and Jackson's fast acting, powerful and effective sink and drain unblocker liquid is perfectly safe to use on all pipe types. For the best results, pour the heavy duty drain unblocker down the plughole, leave for a minimum of 3 hours (preferably overnight) and finish off by flushing the drain with hot water for at least 2 minutes to completely free any blockages - it's really that easy!
SPEAR & JACKSON: With over 250 years experience and continuous innovation, Spear and Jackson have built an enviable reputation with their market leading products that offer high quality performance tools to suit a wide range of needs. Whether you're looking to unblock your sink drain or a concentrated mould, algae and moss spray then shop Spear and Jackson range of versatile, effective and long lasting cleaning products

5 Litre Heavy Duty Sink & Drain Unblocker Strong Cleaning Liquid Plug Hole Toilet Cleaner Tool For Home, Office, Garage & Shops (1 x 5 Litre)

Why We Love It

Unclogs sinks rapidly under 5 minutes.
Super-strength formula clears stubborn blockages.
Safely maintains all types of drains.

Main Highlights

SINK & DRAIN UNBLOCKER: However much you try, sometimes food, hair or other blockages might fall down your sink or drains. Luckily, our sink and drain unblocker will help you get those clogs shifted. Soon you’ll be able to take a shower without it filling up with water or wash up in your kitchen sink without the dirty water getting stuck. Our Sink and Drain unblocker is the fast and effective way to unclog your sinks and drains with one dose. Gets to work really fast in under 5 minutes.
POWERFUL FORMULA: Power through blockages in your drain with our super-strength drain unblocker solution. It's a home essential and can be used on sinks, showers, and outdoor drains. It powers through to the source of the blockage to resolve the issue and give you free running water again. Use regularly to ensure pipes and drains remain problem free.
MULTI USE: Protect your sinks and drains by using this drain unblocker on a regular basis. Out solution is safe for use on all pipes, its perfect for the home, office, workplace, shops and canteens.
SIMPLE TO USE: Add 1 Litre of product to the affected sink or drain and allow the solution to work for at least 5 minutes. For best results, leave for up to 30 minutes and then flush through with hot water. Simple select the amount required from the menu above.

Buster Bathroom Drain Unblocker 300ml, Pack of 3 – Sink Unblocker Removes Hair & Sludge in Showers, Baths & Sinks. Fast-Acting Shower Drain Unblocker Clears Blockages & Slow-Draining Water

9% OffFree Shipping

Why We Love It

Clears hair and sludge swiftly.
Saves showers, baths, and basins.
Fast-acting, efficient blockage solution.

Main Highlights

BATHROOM SINK UNBLOCKER - Buster Bathroom Plughole Unblocker is the one-shot drain unblocker specially designed to blast away hair and soap scum in bathroom drains fast
TARGETS HAIR & SLUDGE - Buster clears bathroom plugholes from the build-up of hair, soap scum and sludge; these are the common plughole nasties that, if not treated regularly, cause the dreaded bathroom plughole blockage
FOR SHOWERS, BATHS & BASINS - Buster Bathroom Plughole Unblocker is specially formulated to tackle the causes of blockages inside your bathroom pipes - It’s suitable for showers, baths, sink plugholes and is safe to use on septic systems
STOPS SLOW DRAINING WATER & BLOCKAGES - Whether it’s a full blockage or slow draining water, Buster’s fast-acting formula gets to work in 15 minutes (for best results leave overnight), dissolving hair and clearing sludge to keep water flowing freely
YOUR PLUGHOLE EXPERTS - For over 30 years we’ve worked obsessively to make plughole care products that are effective and simply get the job done, from clearing and preventing blockages to cleaning and sanitising

Buster Kitchen Plughole Unblocker 150g, Pack of 3 - Kitchen Drains & Sinks Unblocker, Blasts Fat & Food Debris – Fast Acting Plughole Unclogger, Clears Blockages & Slow-Draining Water

Free Shipping

Why We Love It

Powerful against food and fat.
Mends blockages in minutes.
Experienced plughole care experts.

Main Highlights

KITCHEN SINK UNBLOCKER - Buster Kitchen Plughole Unblocker is the one-shot drain unblocker specially designed to target food and fat build-up in kitchen drains and sinks fast
BLASTS FAT & FOOD - Buster's heavy-duty kitchen drain cleaner tackles the build-up of fat and food debris – these are the common plughole nasties that, if not treated regularly, can cause the dreaded kitchen plug blockage
STOP SLOW DRAINING WATER & BLOCKAGES - Whether it’s a full blockage or slow draining water, Buster’s fast-acting sink unblocker targets build-up and melts fat and grease to keep water flowing freely
MIGHTY ONE-SHOT TREATMENT - Buster’s fast and effective unique formulation drops straight to the blockage and works in 20 minutes (for best results leave overnight), ready to flush away blockages inside your kitchen sink and pipes
YOUR PLUGHOLE EXPERTS - For over 30 years we’ve worked obsessively to make plughole care products that are effective and simply get the job done, from clearing and preventing blockages to cleaning and sanitising

Zep Commercial Unblocker Heat Drain Liquid

8% OffFree Shipping

Why We Love It

Melts blockages for easy drain.
Battles grease, fat effortlessly.
Safe for plastic components.

Main Highlights

Heavy duty formulations melts tough blockages
destroys grease, fat &amp
food build-up effortlessly
this professional-strength formula is safe for Plastic pimples
Destroys grease, fat & food build-up effortlessly
This professional-strength formula is safe for Plastic pimples

Strong Heavy Duty Industrial Sink & Drain Unblocker Cuts Through Standing Water Fast Effect 5 Litre Cleaner (1 x 5 Litre)

8% Off

Why We Love It

Unclogs water in minutes.
Effective on various drains.
Safe for all pipes.

Main Highlights

5 Litre heavy duty industrial sink and drain unblocker is designed to cut through standing water that has been caused due to food being trapped in drain pipes or either a build up of hair stuck in showers. It effectively unclogs your sinks in just one dose and gets to work in less than 5 minutes so you can have running water again.
The powerful formula cuts through standing water, clogged toilets and sinks, this is a essential cleaning product used in most homes, offices, workplaces, canteens and shops.
Sink and drain unblocker can be used for sinks, showers, toilets, drains, outdoor drains it powers through to the source of the blockage to resolve the issue and give you free running water again.
We recommend you use this on a regular basis to ensure pipes and drains remain problem free, our solution is safe for use on all pipes and is very easy to use simply add 1 Litre of product to the affected sink or drain and allow the solution to work for at least 5 minutes. For best results, leave for up to 30 minutes and then flush through with hot water.

HOMAITER Drain Unblocker, Powerful Cleaner Formula, 260g, Removes Hair, Grease & Soap Scum, Safe for Pipes and Septic Systems

Free Shipping

Why We Love It

Instantly clears tough clogs.
Safe for all plumbing types.
Easy and quick to use.

Main Highlights

Instantly Clears Blocked Drains: HOMAITER Drain Unblocker is a powerful and effective solution for clearing clogged drains. Quickly dissolves hair, grease, soap scum, and food build-up without damaging your plumbing
friendly product: Ideal for homeowners, renters, and anyone who faces recurring drain issues. Perfect for busy kitchens, bathrooms, and showers, clog remover for sink is your go-to solution for maintaining clean and free-flowing drains
Multiple Uses: Best drain cleaner, safe for use in both kitchen and bathroom drains, it provides a quick, easy fix for stubborn clogs. Simply pour, wait, and enjoy free-flowing drains in minutes
Safe for Pipes and Septic Systems: Safe for use on all types of pipes, including PVC, metal, and older plumbing systems. Compatible with septic tanks
Easy-to-Use: Simply pour and wait 5-10 minutes for quick results—no need for tools. Gentle on your plumbing while effectively clearing tough clogs

Mr Muscle Drain Unblocker, Sink & Drain Cleaner, Fast Acting Heavy Duty Gel Formula, Dissolves Clogs, Works 3x Better Than Bleach, Safe for All Pipes, Duo Pack, (2 x 1L)

Free Shipping

Why We Love It

Powerfully tackles tough clogs.
Quick-action, efficient unblocking.
Safe for all pipes.

Main Highlights

Sink power unblocker to destroy the toughest clogs in your drain
Blocked drain cleaner for dissolving clogs caused by debris in sinks, plugholes and pipes
3x more effective than bleach as a pipe unblocker based on hair removal in laboratory testing
Cuts through standing water to unblock plugholes
Mr Muscle drain unblocker is safe for use on all types of pipe

HG ECO Drain Unblocker, Kitchen Sink & Bathroom Sink Unblocker, Heavy Duty Drain Unblocker, Bath Traps & Waste Water Pipes, Eco Conscious HG Cleaning Products, Recyclable - 1000ml (681100106)

Free Shipping

Why We Love It

Efficient and quick unblocking action.
Eco-friendly, non-toxic formula.
Easy and safe usage.

Main Highlights

HG Drain Unblocker liquid: Bath drain unblocker and sink unblocker liquid, ideal for use in bathrooms, kitchens, washrooms and utility rooms. The plug unblocker quickly gets rid of any blockages
Powerful plug hole unblocker: Bathroom and kitchen drains tackles and removes various blockages, including food, fat, oil and soap. This formula is kinder to the environment using non toxic chemicals
Easy to use bath unblocker: Heavy duty shower drain unblocker liquid ready to tip down the plug hole, does not require dilution. Highly concentrated, works in just 30 minutes. Simply pour, wait, flush
HG eco cleaning products for your home: HG professional grade cleaning formulas are ultra effective yet kinder to the planet. Free from preservatives, phosphates, colourings and microplastics
1 x HG ECO Drain Unblocker, 1000ml, in a bottle made of recyclable materials. Discover the range of HG household cleaning products, with HG bathroom cleaning products and HG bathroom floor cleaner

HG Kitchen Drain & Plug Unblocker, Natural, Heavy Duty, Kitchen Sink Unblocker & Cleaner for Pipes, Septic Tank Safe - 1 Litre

14% OffFree Shipping

Why We Love It

Effective for persistent blockages.
Eco-friendly and biodegradable ingredients.
Prevents future blockages.

Main Highlights

HG Drain Unblocker for kitchen sinks: A fast acting drain unblocker and kitchen sink cleaner. Clears the pipes quickly and easily; ideal for persistent blockages caused by fat, oil and food remnants
Eco conscious formula: The kitchen sink unblocker is made using natural ingredients, including enzymes and microbes, making this cleaner biodegradable and safe for any kitchen drain or septic tank
Quick and easy plughole unblocker: High strength blockage remover gel which gets to work eating away at the blockage. Try this first before calling a plumber! Gentle on sinks, pipes and traps
Easy to use drain cleaner fluid: Can also be used as a sink drain cleaner and de-odouriser. Enhances the bacteria culture of septic tanks and has a preventative effect to help avoid future blockages
Includes: 1 x HG Plughole Unblocker, 1L. Discover the full range of HG professional household cleaning products, with HG Mould Remover, toilet unblocker, shower drain unblocker and all surface cleaner

8.8

Excellent

Save 14%

We scanned 1565 products

We reviewed these offers relevant to the Heavy Duty Drain Cleaners And Unblockers within online retailers such as Amazon, eBay and other local retailers, ensuring we covered all major brands and models. The products we selected come from trusted brands like Spear & Jackson, STORM TRADING GROUP, Buster, Zep, Pluto Packaging, HOMAITER, Mr Muscle, HG, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best Heavy Duty Drain Cleaners And Unblockers in the market, we considered we took a deep dive into 7826 online reviews , focusing on elements like user satisfaction, performance in real-world conditions, and long-term reliability. Our ranking also evaluates each review’s relevancy, authenticity, up-to-dateness and depth so that the comparison is more sound.

We concluded that:

The clear winner of our analysis is Spear Jackson Heavy Duty Sink and Drain Unblocker Gel - Powerful Formula- Indoor and Outdoor, 5 l (Pack of 1). We love many things about this product by Spear & Jackson. What sets it apart from the competition is Effective on tough blockages, Safe for all pipes, Experienced, reputable brand.
The best value product for most shoppers and where user satisfaction is continuously the highest is 5 Litre Heavy Duty Sink & Drain Unblocker Strong Cleaning Liquid Plug Hole Toilet Cleaner Tool For Home, Office, Garage & Shops (1 x 5 Litre) by STORM TRADING GROUP based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for Heavy Duty Drain Cleaners And Unblockers and the best cost-to-value ratio is HG Kitchen Drain & Plug Unblocker, Natural, Heavy Duty, Kitchen Sink Unblocker & Cleaner for Pipes, Septic Tank Safe - 1 Litreat HG with a 14% discount.
Our list of the best Heavy Duty Drain Cleaners And Unblockers is updated regularly to reflect new releases and changes in product availability, so be sure to check back often for the latest rankings and discounts.

10 Best Heavy Duty Drain Cleaners And Unblockers in The UK

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STARWAX Super Powerful Drain Unblocker Gel – 30% Caustic Soda – Works in Standing Water – Fast 30 Min Action – Thick Formula – Kitchen & Bathroom – 1L = 2 Uses

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We scanned 1565 products

We concluded that: