10 Best Outside Drain Unblocker Liquid Heavy Duty Acid in The UK

Last updated on 14/08/2025

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Spear & Jackson

Spear & Jackson - Heavy Duty Sink And Drain Unblocker Gel - 2 x 5 Litres - Clears Blocked Drains

3% Off

Why We Love It

Effective on tough blockages.
Easy to use gel formula.
Trusted brand with heritage.

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

One Chem Professional Heavy Duty Drain Unblocker 2 x 5 Litres, Clears Grease, Fat, Food Deposits, Indoor and Outdoor Use

9% Off

Why We Love It

Powerful and effective formula.
Reduces build-ups and blockages.
Easy and safe usage.

Main Highlights

Powerful Formula: One Chem Heavy Duty Indoor and Outdoor Drain Unblocker is a specially formulated liquid that clears grease, fat, and food deposits in drains, gulleys, and waste outlet pipes.
Maintenance: This liquid also helps maintain sinks and drains to reduce build-ups and blockages.
Usage Instructions: Wear gloves, place bottle on a flat surface, push down on the cap and turn anti-clockwise, pour 500ml of liquid down the drain taking care not to splash in eyes, allow to dwell for a minimum of 3 hours but preferably overnight, then flush with plenty of water.
Effective Dwell Time: For best results, allow the liquid to dwell for as long as possible, with a minimum of 3 hours but preferably overnight.

One Chem - Heavy Duty Sink and Drain Unblocker Gel - 2 x 5L - Powerful Formula- Drain Opener - Pipe Cleaner - Sink Unblocker

3% Off

Why We Love It

Instantly clears fat and deposits.
Dissolves unwanted blockages easily.
Safe for all pipes.

Main Highlights

DRAIN UNBLOCKER LIQUID: ONE CHEM heavy duty sink and drain unblocker is a premium sink unblocker liquid designed to instantly clear fat and other deposits from your drains. These versatile products are ultimate drain unblocker tools. ONE CHEM cleaning supplies are fast acting, powerful and combine super strength action with a faultless formula
MULTIPURPOSE SINK UNBLOCKER TOOL: ONE CHEM drain cleaners and unblockers dissolve unwanted blockages, even through standing water. Use as a kitchen sink unblocker to remove fat, grease and food build-up and as a bathroom sink unblocker to remove soap, bath waste and hair. This debris and hair remover fights through the toughest blockages to restore a clear running drain
HOME IMPROVEMENT: This drain cleaner is an optimum drain cleaning tool for use on internal and external drains. Use as an outside drain unblocker to unclog and maintain drainage. Use as an outdoor drain unblocker as well as a shower unblocker to remove hair and soap residue from the shower plug hole cover and drain
DRAIN MAINTENANCE: Protect your shiny sinks and drains by using this drain unblocker on a regular basis. This gel will get to work quickly in unblocking and draining plug holes. The gel will maintain a fresh running drain. No cleaning gadgets required
SAFE FOR ALL PIPES: ONE CHEM drain unblocker is safe to use on all pipe types. This cleaner will seep through a sink strainer, bathroom plug hole, shower drain cover and kitchen sink plug with ease. This plug unblocker is a premium product to keep your pipes and drains clean and fresh

One Chem - Heavy Duty Sink and Drain Unblocker Gel - 5L - Powerful Formula- Drain Opener - Pipe Cleaner - Sink Unblocker

5% Off

Why We Love It

Instantly clears fat deposits.
Dissolves all unwanted blockages.
Safe for all pipes.

Main Highlights

DRAIN UNBLOCKER LIQUID: ONE CHEM heavy duty sink and drain unblocker is a premium sink unblocker liquid designed to instantly clear fat and other deposits from your drains. These versatile products are ultimate drain unblocker tools. ONE CHEM cleaning supplies are fast acting, powerful and combine super strength action with a faultless formula
MULTIPURPOSE SINK UNBLOCKER TOOL: ONE CHEM drain cleaners and unblockers dissolve unwanted blockages, even through standing water. Use as a kitchen sink unblocker to remove fat, grease and food build-up and as a bathroom sink unblocker to remove soap, bath waste and hair. This debris and hair remover fights through the toughest blockages to restore a clear running drain
HOME IMPROVEMENT: This drain cleaner is an optimum drain cleaning tool for use on internal and external drains. Use as an outside drain unblocker to unclog and maintain drainage. Use as an outdoor drain unblocker as well as a shower unblocker to remove hair and soap residue from the shower plug hole cover and drain
DRAIN MAINTENANCE: Protect your shiny sinks and drains by using this drain unblocker on a regular basis. This gel will get to work quickly in unblocking and draining plug holes. The gel will maintain a fresh running drain. No cleaning gadgets required
SAFE FOR ALL PIPES: ONE CHEM drain unblocker is safe to use on all pipe types. This cleaner will seep through a sink strainer, bathroom plug hole, shower drain cover and kitchen sink plug with ease. This plug unblocker is a premium product to keep your pipes and drains clean and fresh

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

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

MultiWare 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

Powerfully clears stubborn clogs.
Safe for all pipes.
Offers rapid, efficient results.

Main Highlights

MULTIWARE POWERFUL DRAIN UNBLOCKER - Experience the strength of MultiWare's industrial-grade formula, specifically engineered to dissolve stubborn clogs quickly and efficiently. This powerful cleaner tackles everything from hair and soap scum to grease and food particles, ensuring your drains are free-flowing and clean.
SAFE FOR ALL PIPES - MultiWare Sink and Drain Unblocker is thoughtfully formulated to be safe for use in all plumbing systems. Whether your home uses modern PVC, traditional copper, or older metal piping, you can trust our product to clear clogs without causing any damage or corrosion.
RAPID RESULTS - Get quick results when time is of the essence. Our unblocker works within minutes to remove obstructions and restore optimal flow to slow drains, saving you both time and frustration. Simply follow the easy instructions for immediate relief.
EASY TO USE - Avoid expensive plumber calls with MultiWare's easy-to-use drain solution. Our clear, step-by-step guide allows anyone to professionally handle drain maintenance. Just pour the recommended amount into the drain, wait for the formula to work its magic, and rinse away the residues.
VERSATILE APPLICATIONS - Not just for kitchen sinks, MultiWare's Drain Unblocker is also effective in bathrooms, on shower drains, and even outdoor drains exposed to leaves and debris. Its versatility makes it a must-have in any home or commercial setting to tackle a variety of blockage issues.

HG Duo Unblocker, Powerful Drain Cleaner & Drain Unblocker, Kitchen Sink Unblocker & Bathroom Sink Unblocker, Pipe Cleaner, Plug Hole Liquid & Hair Unblocker - 2x 250ml

Free Shipping

Why We Love It

Ultra-effective for stubborn blockages.
Unique 2-component cleaning technology.
Safe and easy to use.

Main Highlights

HG Drain Unblocker duo: Ultra effective drain unblocker for blocked pipes in and around the home. Extremely powerful and recommended for stubborn blockages or persistently clogged drains
Effective multi purpose cleaner for removing stubborn blockages: Kitchen or bathroom plug unblocker, breaks down drain blockages caused by oil, food, debris, soap scum or hair
Shower and bath unblocker: Heavy duty pipe unblocker and drain pipe cleaner uses unique 2-component technology (bottles A and B) which work together to treat the clogged drain
No splash, easy to use: Drain unblocker liquid is safe for all drain types and won't foam or splash. It's ready to use and won't need diluting. Safe to use in kitchen, utility areas and wet rooms
Includes: HG Duo Unblocker, 2 x 500ml. Discover the innovative range of HG professional household cleaning products, including HG mould remover spray, multi purpose cleaners and all surface cleaners

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.

Spear and Jackson 2 x 500ml Heavy Duty Sink and Drain Unblocker

Why We Love It

Instantly clears toughest blockages.
No tools or equipment needed.
Safe for all pipe types.

Main Highlights

SPEAR AND 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 is designed to clear any deposits that are blocking your sink, leaving it draining smoothly
HEAVY DUTY SINK UNBLOCKER: To tackle the build up on fats, foods, hair and soap residue in your bathroom or kitchen sink that is blocking your drains, Spear and Jackson's heavy duty sink and drain unblocker is specifically designed to instantly clear and dissolve the unwanted blockage quickly and efficiently
NO DRAIN SNAKE NEEDED: No need to waste your time with drain rods, this product requires no tools or equipment as it swiftly dissolves any build up. 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 entire bottle of 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 AND 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

8.7

Excellent

We scanned 286 products

We reviewed these offers relevant to the Outside Drain Unblocker Liquid Heavy Duty Acid 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, One Chem, Zep, MultiWare, HG, STORM TRADING GROUP, Spear Jackson, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best Outside Drain Unblocker Liquid Heavy Duty Acid in the market, we considered we took a deep dive into 1431 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 - 2 x 5 Litres - Clears Blocked Drains. We love many things about this product by Spear & Jackson. What sets it apart from the competition is Effective on tough blockages. , Easy to use gel formula. , Trusted brand with heritage. .
The best value product for most shoppers and where user satisfaction is continuously the highest is One Chem Professional Heavy Duty Drain Unblocker 2 x 5 Litres, Clears Grease, Fat, Food Deposits, Indoor and Outdoor Use by One Chem based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for Outside Drain Unblocker Liquid Heavy Duty Acid and the best cost-to-value ratio is One Chem Professional Heavy Duty Drain Unblocker 2 x 5 Litres, Clears Grease, Fat, Food Deposits, Indoor and Outdoor Useat One Chem with a 9% discount.
Our list of the best Outside Drain Unblocker Liquid Heavy Duty Acid 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 Outside Drain Unblocker Liquid Heavy Duty Acid in The UK

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We scanned 286 products

We concluded that: