What Is The Best Drain Unblocker In The UK? (read this)

Wherever you live, you will at some point have come up against a blocked drain. Either in the kitchen or the bathroom or both at the same time. It’s usually at the most inopportune moment, not that there’s a good time for the drain to block. In this article we’ll look at the most popular drain unblockers on the market and advise you on which one to keep in your cupboard for when your drains finally decide to stop draining.

What Is A Drain Unblocker?

Put simply, a drain unblocker is a chemical preparation that is poured into the sink which cuts through the gunk that’s blocking the drain and allows a free flow of water again. There are a number of proprietary brands of drain unblockers available from shops and stores in the UK. 

They all work in a similar way; They are poured into the blocked sink and left for a period of time to do their magic. You then run fresh water into the sink and it should be clear again.

How Do Drain Unblockers Work?

The majority of drains get blocked by food, grease, fats or other nasty stuff that goes down the plughole. Drain cleaners come in two forms which are;

  1. Enzyme Based
    These work by dissolving any organic obstruction in their path without damaging your pipes. They are the safest option available and should always be used when cleaning toilets and other waste disposals. They are suitable for both kitchens and bathrooms.
  2. Chemical Based
    These work by reacting with whatever is causing the blockage and removing it by some sort of chemically induced heat. Extra care needs to be employed when using any chemical based cleaner as they can cause injury to the skin or if ingested in any way (including breathing). Never use chemical cleaners on toilets or waste disposals or anywhere that’s likely to overflow when blocked. 

Never use a plunger after pouring a chemical drain unblocker down the sink and never mix chemicals.

How To Choose A Drain Unblocker


As there are so many brands of drain unblocker on the market, it’s vital you choose the one best suited to your personal needs and preference. So let’s look at some of the choices available to you.

Type Of Unblocker

Drain unblockers come in 2 main types; 

  1. Those for kitchens
  2. Those for bathrooms

Choosing the correct type of unblocker will make a difference to the outcome of its performance. Kitchen unblockers target grease and detergents, whereas bathroom unblockers target soap and hair.

As well as room specifics, you’ll also need to look at whether to choose a liquid, gel, powder or a granular unblocker. We have found that liquids perform better as the liquid will stick to the sides of the pipe as well as tackling the main blockage. Liquid unblockers are also more general in as much as they will tackle grease and hair as well as soap, detergents, oil and anything else.

Type Of Pipe

Some homes have PVC piping and others have some sort of metal piping. Check that the product you purchase is suitable for the piping that you have.

Time It Takes

There are a number of drain unblockers that take around 20 to 30 minutes to work. Others need to be left overnight to be effective. However long your chosen product takes to work, you need to ensure that no water enters the pipe whilst the unblocker is working.

Scented Or Unscented

There are some drain cleaners that are odourless which means you’ll get some smelly drain smells in your home whilst the pipes are clearing. Others have an artificial chemically fresh sort of smell. The choice is yours, some people can’t stand that artificial fresh smell whilst others prefer that to the drain smell.

Exterior Or Interior Drain Clearers

Drain unblockers are usually specific, some work on exterior drains whilst others are for interior drains. They use different ingredients and should never be used for the wrong purpose. If you were to use exterior drain clearers indoors there’s a strong likelihood of damaging your pipes.

Size (Quantity)

There are drain unblockers ranging in size from 300ml up to 2 litres, the size you choose will depend on the size of your household, your cupboard space and your budget. If you have a large family, there’s more chance of the sink becoming blocked sooner rather than later and it’s always good to have an unblocker on stand by.

Obviously a larger quantity will cost more initially, but often buying in bulk saves money in the long run. If you have young children, you’ll need to keep the drain unblocker out of their reach, as you do all chemicals which means finding room in your probably already overstocked cleaning cupboard.

Convenience Of Use

Many drain unblockers need some sort of preparation before they can be used, which is great if you have plenty of time. But we find liquid drain unblockers with their simple pour into the drain and leave for around 30 minutes before flushing work best.

Plus as drain unblockers are chemicals, you need to take care when mixing or preparing them as any chemicals can be dangerous. So any that need mixing or stirring can be inconvenient to say the least.

One Shot Or Reusable?

There are a number of single use or one shot drain clearers on the market which can be quite effective. However, if your sink is totally blocked, it might take more than just one shot. This makes this type of unblocker more expensive in the long run. We find it better to buy a large bottle that can be reused if the blockage isn’t cleared completely in one go.

Buying a large bottle also works out costing less money overall, and also ensures you have more unblocker on hand for the next time the sink blocks.

You should always read the instructions on the bottle for the correct way to use the drain clearer.

How To Use A Drain Unblocker Effectively

It can be very tempting to get the unblocker home and immediately start pouring it down the sink. But that can be extremely dangerous. Generally you should:

  1. Remove any water sitting in the sink
    This can be done using a jug or a saucepan, keep going until all of the water is removed from the sink.
  2. Open the drain clearer and use as instructed
    Some need to be squeezed into the drain, others are just poured using no external force at all. Check the bottle for the manufacturer’s instructions and follow them to the letter
  3. Take care
    Remember you are handling chemicals strong enough to melt fat and hair. Those same chemicals should never touch your skin. Be careful and always take adequate precautions (wear gloves etc).
  4. Allow enough time for the cleaner to work
    Never be tempted to run water down the drain to see if it’s working before the instructed time. Whether that’s 30 minutes or overnight, allow the cleaner to do its work.
  5. Once the correct time has elapsed, rinse with water
    After allowing the full time period to elapse, rinse the drain using water, again the instructions will stipulate whether to use hot or cold water.
  6. Store any unused cleaner safely
    If you bought a large bottle of drain clearer store the residue somewhere safely away from children.

Best UK Drain Unblocker Reviews


We tried and tested the best drain unblockers on the market in the UK, below are our findings.

Mr. Muscle Power Gel Drain Unblocker

The Mr. Muscle Power Gel is available in 500ml and 1ltr bottles and can be used for a septic tank as well as a general drain. It comes in a single use plastic bottle but buying the larger size allows more than a single use. It is a fast and effective way to unblock the drain and can work within just 5 minutes. 

Mr. Muscle Power Gel works just as well in the shower for blockages caused by hair as it does in the kitchen on blockages caused by grease etc. If speed is of the essence, this is the unblocker for you.

Cillit Bang Drain Odour Eliminator & Unblocker Gel

The Cillit Bang Drain Odour Eliminator & Unblocker Gel comes in a 500ml bottle and although it is claimed to be safe to use on a septic tank, the manufacturer states they are unable to test on all septic tanks. You will need to check with your provider before using.

We found it wasn’t the fastest product we tried but it does work if left long enough and it’s affordable too. 

Buster Kitchen Plughole Unblocker

The Buster Kitchen Plughole Unblocker can be used with a septic tank and comes in a 200g bottle. It does clear the original blockage but tends to create a new blockage due to the sheer mass of the granules left behind. However, that second blockage was easy to remove with just one push of the plunger.

You have to buy separate bottles of Buster, one for the kitchen and a different one for the bathroom. The Buster Bathroom Plughole Unblocker proved to be very effective at removing the blockage in the bathroom. We noticed lots of hair passed through the cleared pipe after use.

Domestos 15 Minute Sink & Pipe Unblocker Gel

The Domestos 15 Minute Sink & Pipe Unblocker Gel comes in a 500ml bottle and is suitable for septic tanks. It does exactly what it says on the bottle, unblocks the pipes in 15 minutes. The only problem we found with this product was the instructions are printed in incredibly small letters on the bottle. It is, however, very simple to use.

HG Drain Unblocker

The HG Kitchen Drain Unblocker comes in a 1ltr bottle and is suitable for septic tanks. However, the HG Hair Unblocker which is for the bathroom, isn’t suitable for septic tanks.  

HG Kitchen Drain Unblocker

This one takes some work on your part as it needs to be mixed with water and then left for 6 hours. It does work effectively if you don’t mind leaving it for the 6 hours (or overnight).

HG Hair Unblocker

As we said, you can’t use this one if you have a septic tank plus you need to pour both bottles down the drain in one go. It takes approximately 1 to 2 hours to clear the shower drain.

Soda Crystals

You were probably told about soda crystals by your granny, as they’ve been used around the home for many years. They worked really well in the kitchen drain but failed to clear the shower drain of blocked hair. The main problem with soda crystals is the work involved with preparing them for use.

You need to create a solution by diluting the soda crystals in warm water before pouring that solution into the drain. It will then remove the blockage from your kitchen within an hour. Soda crystals are the cheapest drain unblocker, and are suitable for use with septic tanks and come in a 1kg packet.

They can also be used to clean many household products including pots and pans, barbeques, washing machines and removing stains from clothes.

How To Prevent Drain Blockages (Prevention Is Better Than Cure)

Once the drain is unblocked, it’s advisable to find ways to stop it getting so clogged again. In many cases serious blockages are avoidable if you follow these simple steps;

Ways To Prevent Drains From Blocking

If you always follow this advice, you will minimise the amount of blockages you have to deal with.

  • Remove food from your plates
    Always scrape all of the food from your dirty dishes before washing them to prevent any build up in the drain. 
  • Buy a drain protector
    A drain protector sits on top of the plug hole and catches any stary particles that could potentially cause a blockage in the pipe.
  • Never pour fat or grease down the sink
    Collect any fats or grease from cooking in a suitable container and dispose of it in your general waste.
  • Use a drain cleaner frequently to prevent blockages
    Get into the habit of using a drain cleaner at least once a month to prevent the pipes from getting clogged again.

Does Bicarbonate Of Soda And Vinegar Unblock Drains?

We tried using a mixture of bicarbonate soda and vinegar to unblock our sink and found it to be ineffective. We poured equal amounts of bicarbonate of soda and vinegar down the drain, left it for 60 minutes and then had to use a plunger to remove the blockage.

Frequently Asked Questions

What do plumbers use to unblock drains?

Plumbers use a plumber’s snake to unblock drains. This is a boring tool that spins as it is physically pushed through the pipe and eventually through the blockage. It takes time, patience and strength to use correctly. Too much pressure could damage the pipe, not enough and the blockage stays where it is.

Will bleach unblock a drain?

Bleach is great for deodorising a drain, but if that drain is blocked you should never use bleach. Not only will bleach not clear the blockage but it could react with whatever proprietary unblocker you eventually have to use.

Does baking soda and vinegar clean drains?

Baking soda and vinegar can help to clean drains naturally, but if the drain is blocked, you will need to use something stronger, like a proprietary drain unblocker.

How long do drain unblockers take to clear drains?

The amount of time needed by a drain unblocker to clear a drain depends on the product. Read the instructions on the bottle for directions. There are some drain unblockers that will work within minutes whilst others can take all night to work.

Will vinegar hurt PVC pipes?

Vinegar will not harm your pipes whether they are PVC, copper or any other type of construction as long as you don’t leave it in the pipe for too long.

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