The best leak detection sprays, compared.
Top pick: Liqui Moly 3350, 400 ml Best value: Arctic Hayes PH026M, 120 ml – Lowest shelf price that still states BS EN 14291:2004 and has a UK review file: about £3.83, 4.2 from 98. Updated October 2026.
A leak detection spray, and the brush-on leak detection fluid sold beside it, lays a surfactant film on a joint that is already under gas or air pressure so a leak shows as bubbles. In the UK you use one on a visible LPG fitting, a caravan or barbecue hose, or a pressurised pipe you are allowed to check. A smell of gas indoors starts with a call to the National Gas Emergency Service on 0800 111 999, not with a can. The joint has to be reachable and already under pressure. Use a proprietary leak detection fluid, then wipe it off. Washing-up liquid is a corrosion risk on corrugated stainless meter connections. A listing that states BS EN 14291:2004 is the line an MOT station, other than class 1 and 2, must hold. An aerosol covers several joints. A brush aims at one. A CFC-free line is not a non-flammable claim. Choosing a brush or an aerosol is set out in the [leak detection spray buying guide](/hub/measuring-equipment/leak-detection-spray/sub/leak-detection-spray-buying-guide). The film does not replace a tightness test or authorise gas work.
A leak detection spray, and the brush-on leak detection fluid sold beside it, lays a surfactant film on a joint that is already under gas or air pressure so a leak shows as bubbles.
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Personal buying guide
Question 1 of 2
Does the listing need to state BS EN 14291:2004?
Liqui Moly 3350 is a 400 ml leak finder spray, captured at £9.38, and the listing says it shows leaks in gas and compressed air on containers, pipes, hoses, threads, welds, flanges, and fittings. The rating line is 4.5 from 2,232 reviews, the largest count in this set. In the first 50 blocks only five are United Kingdom, and those five are short praise that it does what it says, including on gas leaks. The other texts are not British shopper opinion: some mention bubbles on a motorhome gas check and a gas barbecue, and others say the spray stays thin, foams little, and in one case missed a fuel-system leak that soap showed more clearly. Car tyres, plastic pipes, and flammability are questions on the listing with no answer in the saved bullets. BS EN 14291:2004 is not stated. A high star line here is not a UK leak-rate test.
Pros
Cons
Best for: A compressed-air or gas fitting when you want a 400 ml named spray and you will not treat the 2,232-review line as British opinion.
Less suitable: A buyer who needs UK review text, or a stated British Standard, on the Amazon card before they order.
Specifications
Common questions
What does the Liqui Moly listing say it finds?
Leaky points in gas and compressed air, on containers, pipelines, hoses, threads, welds, flanges, and fittings. Volume is 400 ml.
Does it answer car tyres, plastic pipes, or flammability?
Those three questions are on the listing and are not answered in the saved bullets.
Are the 2,232 reviews a UK sample?
The rating line is 4.5 from 2,232. In the first 50 blocks, five are United Kingdom and they are short praise. The rest are not United Kingdom.
The Rothenberger RoTest is a 400 ml tin spray, captured at £10.99, for gas lines, cylinders, containers, valves, and pipe connections. The bullets say it is neutral towards common flammable gases and refrigerants, apart from foam, and they do not cite BS EN 14291:2004. Amazon.co.uk shows 4.4 from 154 reviews. The saved file holds one United Kingdom review, which says the spray is ready to use and less messy than mixing soap and water. Other blocks are not UK: they say it worked, including on a gas barbecue cylinder, and they also say the foam is thin and drips off the joint. Indoor use is asked on the listing and not answered. The maker's UK page uses DVGW wording, which is not the same claim as BS EN 14291. At the top of this price band you are buying a named cylinder spray with a thin UK text sample.
Pros
Cons
Best for: A cylinder, valve, or pipe connection where the listing's cylinder wording is what you came for, and a thin UK review sample is acceptable.
Less suitable: Anyone who reads DVGW on the maker's site as BS EN 14291, or who wants a stack of UK reviews before they pay £10.99.
Specifications
Common questions
What joints does the RoTest listing name?
Gas lines, gas cylinders, containers, valves, and pipe connections. It says the spray is neutral towards common flammable gases and refrigerants, apart from foam.
Does the listing cite BS EN 14291?
No. That sentence is not in the saved bullets.
Is indoor use answered?
The listing asks and does not answer. The saved UK review says it is ready to use and not messy compared with mixing soap and water.
The Arctic Hayes PH026 is a 250 ml brush-on leak fluid, captured at £4.33, and the bullets say it meets BS EN 14291:2004 and is non-flammable and non-corrosive in confined areas. Across 106 amazon.co.uk reviews the line is 4.3, and the saved review blocks are United Kingdom. Reviewers describe bubbles locating a leak, including on a hot tub, and a brush that puts fluid on the joint without spraying the surrounding pipe. The brush has detached from the lid often enough that you should check the bristles before you treat a dry joint as sound. Contamination is the other repeated complaint: once the fluid is dirty it works less well. The listing leaves small leaks, plastic pipes, and drinking-water pipes unanswered. It is the top pick here because the standard is stated, the UK review file is readable, and 250 ml costs about 50p more than the 120 ml sibling.
Pros
Cons
Best for: A toolbox or a van where you want 250 ml of fluid that states BS EN 14291:2004 and a brush you can aim at one joint.
Less suitable: Oxygen systems, and a row of fittings where you would rather spray than keep reseating a brush.
Specifications
Common questions
Is the PH026 a spray can?
No. The listing is a 250 ml leak detector fluid with a brush in the cap, captured at £4.33.
Does it state a British Standard?
Yes. The bullets say it meets BS EN 14291:2004, and that it is non-flammable, non-corrosive, and for confined areas.
Will it confirm drinking-water pipes?
The listing asks and does not answer. The same is true of the plastic-pipe question.
The Arctic Hayes PH020 listing is a pack of two 400 ml aerosols, captured at £11.98, and the bullets say the spray meets BS EN 14291:2004 and is non-flammable and non-corrosive for positive-pressure leaks in pipelines and fittings. Amazon.co.uk shows 4.3 from five ratings, and the saved listing has no review bodies, so there is no UK account of foam, a dead can, or a loose nozzle. The title says pack of 2 while the included-components line names one 400 ml spray, so the box count is something to check when it arrives. The listing does not answer whether it suits all gases. The maker's page says this aerosol is not for medical oxygen, which the saved Amazon bullets do not repeat. It is the aerosol in this set that states the standard, and it is also the row with the least written evidence.
Pros
Cons
Best for: A workshop that wants an Arctic Hayes aerosol stating BS EN 14291:2004 and can accept five ratings with no written reviews.
Less suitable: A first can for a caravan, where you want review text about dead aerosols, and anyone who needs the pack count to be unambiguous.
Specifications
Common questions
Does the PH020 state BS EN 14291?
Yes. The bullets say it meets BS EN 14291:2004, and that it is a non-flammable, non-corrosive aerosol for positive-pressure leaks.
Is it one can or two?
The title says pack of 2 and the unit count is 2. The included-components line names one 400 ml spray.
What do reviewers say?
The rating line is 4.3 from 5. The saved listing has no review text, so there is nothing further to quote.
The Everbuild P18 is a 400 ml aerosol with a directional tube, captured at £8.38, and the bullets say it is CFC-free and suitable for most gas types on pressurised pipe systems. Amazon.co.uk shows 4.2 from 413 reviews, and the first 50 blocks in the file are all United Kingdom. Those reviews describe bubbles on a cooker hose, a caravan bottle connector, and campervan hoses, and several say it is easier than mixing soap and water. A large share of the same sample describes a can that dribbles, has no propellant, or runs out of gas while the tin is still half full. Foam that is too thick to read, or that disappears within a minute, is also reported, and a working spray is called strong and messy. The saved Amazon bullets do not state BS EN 14291:2004, and the propane question on the page is unanswered. The maker's data sheet lists oxygen and a stand-off of 25–30 cm, which is that sheet's instruction, not a line on this Amazon card.
Pros
Cons
Best for: A caravan hose or a cooker joint when you want a 400 ml can and you can return a tin that only dribbles.
Less suitable: A job that needs BS EN 14291 printed on the listing, and a day when a dead can would leave you with no film.
Specifications
Common questions
Does the Everbuild listing cite BS EN 14291?
No. The saved bullets do not state that standard. They say CFC free, suitable for most gas types, and a directional tube.
What do the UK reviews say?
The first 50 blocks are United Kingdom reviews. Praise is bubbles on a cooker hose, a caravan bottle, and campervan hoses. A repeated complaint is a can that dribbles or has no propellant.
Does it confirm propane?
The listing asks whether it works on propane and does not answer. The bullets say most gas types.
The Arctic Hayes PH026M is a 120 ml brush bottle, captured at £3.83, and the Amazon bullets say it meets BS EN 14291:2004 and is non-flammable and non-corrosive. Amazon.co.uk shows 4.2 from 98 reviews. The saved UK texts say it finds small leaks quickly, including an air leak after other liquids had failed, and that the bottle is small enough to carry. The same notes say the brush keeps falling off, and one bottle arrived with fluid leaked and dried on the neck. Some buyers, once they see the bottle, call it dear for the volume. The bullets claim indoor and confined-area use and a micro-porous foam for the smallest leaks, and they leave plastic pipes unanswered. The maker's own page adds that this fluid is not for oxygen, which the saved Amazon bullets do not print. It is the best value in this set as the lowest price that still states the standard, if a small bottle and a loose brush are acceptable.
Pros
Cons
Best for: An occasional check of one or two visible, pressurised joints when you want the stated standard at the lowest price in this set.
Less suitable: A run of joints that will empty 120 ml quickly, oxygen systems, and anyone who needs a brush that stays in the cap.
Specifications
Common questions
Does the PH026M state BS EN 14291?
Yes. The bullets say it meets the requirements of BS EN 14291:2004. They also say it is non-flammable and non-corrosive.
How do you apply it?
The listing says the brush is built into the bottle cap. UK reviews say that brush can fall off, and one bottle arrived with fluid dried on the neck.
Does the listing answer plastic pipes?
No. The question is on the page and the bullets do not answer it. They do claim indoor use and confined areas.
Six leak detection spray and leak detection fluid listings on amazon.co.uk were scored on 21 October 2026 from the 19 October 2026 shelf capture and the review notes already on the rows. No laboratory leak-rate test was run. Each row starts from the amazon.co.uk star rating times 20, then moves for a stated BS EN 14291:2004 line, a non-flammable and non-corrosive claim, how much of the saved review text is from the United Kingdom, and repeated applicator faults. Star line, stated standard, UK review text, applicator faults and the non-flammable claim are weighted 50, 20, 15, 10 and 5. A CFC-free line is not the non-flammable claim. DVGW wording on a maker page is not treated as BS EN 14291. The best-value row is the lowest shelf price that still states the standard and has a UK review file. A bubble film is not a Gas Safe sign-off.
Star line
50%The start of the score is the amazon.co.uk star rating times 20. A 4.5 line starts at 90. A 4.2 line starts at 84. Stars are not a measured leak rate, and a large count does not add points on its own.
Standard stated
20%Points when the saved Amazon bullets say BS EN 14291:2004. In this capture that is the three Arctic Hayes listings. Everbuild, Liqui Moly and Rothenberger do not receive it. DVGW on a maker page is not that standard.
UK review text
15%A large headline count whose first 50 blocks are mostly not United Kingdom is marked down. A single UK review is marked down. Ratings with no review bodies are marked down further. Non-UK text is not read as British shopper opinion.
Applicator faults
10%UK reviews of cans with no propellant, a brush that detaches, a bottle called dear for its size, and a pack count that disagrees with the included line, all reduce the score.
Non-flammable claim
5%A small uplift when the bullets say non-flammable and non-corrosive. A CFC-free line is not that claim. The uplift is not a flammability test.
Start with the joint, then whether the fluid is proprietary, then whether the listing states BS EN 14291:2004, then the applicator and the gas limits on that can. The notes below follow that order for these six listings. None of the scores is a laboratory leak-rate test.
A leak detection spray, and the brush-on leak detection fluid sold next to it, lays a surfactant film on a joint that is already under gas or air pressure so a leak shows as bubbles. UK shoppers use it on visible LPG fittings, caravan and barbecue hoses, and pressurised pipes. A smell of gas indoors starts with a call to the National Gas Emergency Service on 0800 111 999.
The film only shows a leak when gas or air is already leaving the joint. A dry fitting with no pressure will not grow bubbles, and a quiet film is not proof the joint is sound.
Technical Bulletin 059 names washing-up liquid as a corrosion risk on corrugated stainless meter connections. Use a proprietary leak detection fluid, and wipe it off stainless and brass afterwards.
UK reviews of one 400 ml aerosol in this set often describe no propellant, or foam that is too thick to read. A dribble is not a film. Check the nozzle before you treat a silent joint as tight.
You need bubbles on a reachable, pressurised joint. You do not need a pool dye, a refrigerant UV dye, or an electronic sniffer. Gas Safe Technical Bulletin 059, quoting IGEM/UP/1B and IGEM/UP/1C, says only proprietary leak detection fluids, no fluid above 30 ppm halogens on stainless steel, and no ammonia-bearing fluid on copper or brass. Washing-up liquid is named as a corrosion risk on corrugated stainless meter connections. Wipe the fluid off afterwards.
A brush is easier to aim at one joint. The PH026 and PH026M brushes sit in the cap, and UK reviews say those brushes detach. An aerosol covers several joints faster. On the Everbuild file, a repeated complaint is a can with no propellant. Gas limits belong to that can. Everbuild’s sheet lists oxygen and a 25–30 cm distance. Liqui Moly cites EN 437 families, 0 °C to 50 °C, 30–50 cm, and a rinse of copper and PVC.
Three typical situations, each with a recommendation from this comparison.
You want one can for a hose and a regulator you can isolate, and you can return a tin that only dribbles. The Everbuild P18 is a 400 ml aerosol at about £8.38, with 4.2 from 413 reviews. The first 50 texts are United Kingdom and include bubbles on cooker and caravan joints. Many of those same reviews describe a can with no propellant. BS EN 14291:2004 is not in the saved bullets.
You want 250 ml of brush fluid that states BS EN 14291:2004, aimed at one joint. The Arctic Hayes PH026 is about £4.33, with 4.3 from 106 reviews and UK review text. The brush detaches from the lid often enough that you check the bristles before you treat a dry joint as sound. It is not a spray, and the saved bullets do not print an oxygen exclusion.
You want the stated standard at the lowest shelf price in this set, and a 120 ml bottle is enough. The Arctic Hayes PH026M is about £3.83, with 4.2 from 98 reviews. UK reviews say the brush falls off, and some buyers call it dear once they see the volume. The maker’s page says this fluid is not for oxygen.
The top pick is the Arctic Hayes PH026 at about £4.33. It is a 250 ml brush-on fluid whose bullets state BS EN 14291:2004, with 4.3 from 106 amazon.co.uk reviews and UK review text. The brush detaches, and contamination is reported to stop the fluid working as well. Best value is the Arctic Hayes PH026M at about £3.83, the lowest shelf price in this set that still states the same standard, in 120 ml, with 4.2 from 98 reviews. UK reviews say that brush falls off. Everbuild, Liqui Moly and Rothenberger do not state BS EN 14291:2004 in the saved bullets. None of these scores is a laboratory leak-rate test, and a bubble film does not replace a tightness test.
Arctic Hayes PH026M, 120 ml
Lowest shelf price that still states BS EN 14291:2004 and has a UK review file: about £3.83, 4.2 from 98.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources from the research digest, last checked on 19 October 2026. Shelf prices and star lines are the amazon.co.uk figures captured with these six listings. The price bands are this set, not a market average.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are from the UK listings checked on 19 October 2026. We did not lab-test these leak detection sprays.
