Problems With Bristan Easyfit Kitchen Taps - Part 3

With the help of Bertie (Albert Erskine), Hamish the Plumber suggests a redesign of Bristan’s Easyfit kitchen taps that might prevent future models from flooding people’s houses, and he continues his call for Bristan to make a product recall of the 2014 to 2016 models which use grub screws to secure the tap to its base.

[@772pcs]

Just watched your third video Hamish, I congratulate you for exposing this company. I`m just a di-yer and installed one of these 15 months ago. My wife phoned me hysterical today as the tap had blown off. She did not know how to turn the water off, it was hitting the ceiling. The amount of water tripped the fuse box making it impossible to talk her through the procedure ( an isolator value behind kitchen drawers where you need light) 45 minutes later I got there. Hopefully, because of laminate and a stone floor, (swept the water out of the front door) the only damage is to the ceiling.(no kidding) Sadly I don`t think they will admit liability to any of this is because of the potential insurance claims like ours, much, much more than a tap exchange. I, like many others out there, think they have not tightened the screws enough. - I`m forgiven again thanks :) Many thanks again for the video. We need more guys like you out there to expose these flaws. Just a thought, an ugly fix, a new screw instead of the grub screw with a lock nut. That`s the way I`ll be going with company that won`t own up.

[@handyandy6050]

Absolutely amazing videos, Hamish! (and Bertie)!

[@keithbanbery940]

Thank you for this video. I was checking reviews of the Bristan Easyfit taps with a mind to buying some, but after your informative (and somewhat entertaining) video I have changed my mind. It is a pity that Bristan are shirking their responsibilities to their customers as I am very pleased with other taps they have made, and expected better from them. Thank you, again.

[@pipalia]

Thank you very much for sharing this, we just bought one and after seeing your video, planning to return it back to Screwfix ASAP!

[@rogerfallon4911]

Hi Hamish, I had already purchased a Bristan Renaissance EASYFIT tap and was looking to KZbin for help. I found your video very informative and probably saved a kitchen disaster. I used Loctite 243 thread locking (blue medium strength) on the grub screw before fitting. I tightened thoroughly and then put some Loctite 243 on the threads behind the grub screw as a further check. Fortunately, as I have fitted it myself, I will be able to monitor the tap for security. I hope that as Loctite 243 is used in water pumps to prevent vibration working screws loose this will solve the problem. I have used it computer disc storage systems with high vibration successfully previously. Thanks again for your work on this great video.

[@HamishErskine1]

Hi Roger, my guess is that will work. However, I would normally recommend checking the grub screws regularly with the allen key. But if you do that, it might break the loctite seal. My question is how you will monitor the grub screws? They don't have to loosen very much before the tap's security is at risk, and I am not sure you will be able to tell very easily just by looking at them. Although loctite is probably an ok solution for individuals like yourself, and Bristan could include a tube of loctite with every tap, it would be a solution very prone to installer omission - the reality is lots of installers, whether diy or professional plumbers, don' t read the installation guide, especially when Bristan advertise that installation is as easy as 1-2-3, see www.bristan.com/easyfit

[@barryhaeger4284]

Thanks useful video series. I have just bought one of the Echo taps you are fond of 🙂 I was looking for clarity on installing on a stainless steel sink top with the spreader which is not referenced in the awful fitting instructions, but got more than I had bargained for. Video 1 made doubt my purchase. Video 2 made me doubt I'd the same base but all was clear that Bristan had significantly redesigned the fixing for the grub screws in the 2021 base. Now the screws fix into 2 of 4 straight drilled holes removing the effect of the lateral vector forces imparted by the vertical forces of the mains water pressure. That said i think locktight on the grub screws is a worthwhile precautions.

[@peterbrown6249]

Im so glad i have seen this video. I now off to tell my customer to send back the easyfit and why. I just could not sleep at night if i installed this. The fault can be easily rectified. But i am surprised that the designer did not see the weakness. Disappointed. Thanks for putting this out.

[@keithbunting8675]

Thanks Hamish for your excellent trilogy of videos! I bought a Bristan Echo easyfit a couple of days ago having read the ease of fitting reviews on the ScrewFix website. Then when I came to fit I came across your comments about some of the known problems with these taps. At this point I regretted my decision to purchase the Bristan but I was by now committed. Old tap was off. Water was off.....so I was in a way too far into the job to turn back! Decided to go ahead anyway. The so called push fit connector is an updated one with much improved grub screws having a conical point and running into drilled holes in the base. The overall quality of the unit is good, and Its heavy and well made. The fitting of the push fit connector was however not without complications and I think maybe the word Easyfit should be considered with caution. My connector would'nt go through the sink top hole....the sink is a composite one and quite thick. So I had to split the connector and feed part of it up from underneath. I'm not as young as I was and this was an awkard and difficult thing for me to execute! However everything is now together and working. I've used studlock on the grub screws. The tap looks nice but frankly I wouldn't recommend these taps at all. It's a brilliant concept poorly executed. I will keep an eye on the grub screws but have to say why am I feeling I have to maintain a kitchen tap? I will definitely shut them off when we go away....which basically means I have reservations about their efficiency and safety. Which is in itself a poor reflection on Bristan. At this point I am thinking I will keep this tap for maybe a year and then change it.....just really for peace of mind!

[@barbarahills6420]

Crikey - glad I stumbled on your KZbin channel Hamish. I have one of those taps that I fitted myself more than 5 years ago. It has always occasionally dribbled but no other problems and def no explosive gushers! But just lately it has started squealing and I chanced upon your vid whilst looking for a new washer. After watching your clips I had a look at the tap and found one grub screw completely loose so tightened it up which seems to have stopped the squealing. We’re going away for a week tomorrow; now I think I might shut the water off! I shudder to think what bad fork in the road I just sailed past....

[@robertbailey8003]

I am about to have the Monza version fitted tomorrow morning. I have just checked the design and the angled slot is now a hole with a conical bottom and the screws have a conical tip. A tube of Molykote 111 is also included. After a quick google Molycote 111 is a lube for O rings.

[@alexramsey1006]

Thank you so much for letting us know!!

[@neilhunt7895]

i fitted my first easyfit tap today, something about it didnt feel right, came home and saw these films, i will be changing it asap and running it in to the scrap man !!!!!

[@HamishErskine1]

£2 per kilo of brass is about what these taps are worth. But if you're a plumber you might want to first take out the ceramic disc cartridges. Perhaps you'll be able to use them somewhere to fix a dripping tap.

[@deanos102]

Thank you , i was looking for fixing a dripping easy fit tap and came across your video, my tap had the triangle grub screws and was the first version of this tap , tap has been removed today and different make fitted , Bristan tap in the bin !

[@64bitAtheist]

Glad I found these 3 videos before my tap popped. It is a 2018 fit and appears to still have the original fault. The tap is dripping on the hot side after only 24 months which made me go in search of a fix, now I'm aware that it being loose means I'm close to a flood event.

[@The007Weasel]

Hi Hamish, Thanks for an excellent quality set of videos, which I only stumbled across after doing a search for thread size on Bristan monobloc mini mixer tap pipe tails. I had to disturb some pipework to fix a seeping leak on a copper joint, and wanted to replace the original rigid pipe tails with flexible hoses. It’s a 20 year old tap, but low usage so still good as new. Screwfix offer a 10mm x 15mm x 300mm hose so I’m thinking do they mean 10mm thread or just pipe bore? It’s approx 1/8BSP size as I recall. Nothing found on Google, so will have to disassemble and get the thread gauge on it. Anyway, I watched all 3 of your videos because being a retired aircraft maintenance engineer, it was nice to see you’re very dedicated to quality control and the whole closed loop process, even suggesting a design improvement. Moving the seals from the spigots on the base to the bores in the tap body is clever, but seals in small internal bore grooves are hard to get out, and difficult to inspect, compared to on the male spigot. OK if you were replacing the tap anyway, but a bit fiddly if you only wanted to replace perished seals. I thought it ’s funny that Bristan’s instructions cheekily go into extreme detail telling plumbers how to use an allen key, whilst in gross contrast, not one word in the maintenance section about check tightening the grub screws every 6 months, or when the tap body appears loose. If they did that, it would cost them nothing, and any complaints, they’d be able to fob off with; not our fault if you didn’t follow the maintenance requirements supplied with the product! But that’s an unfair get-out….you shouldn’t need a maintenance schedule for a sink tap! I suspect the guy at Board level in Bristan won’t even know how to fit a tap. He’ll be into profit rather than plumbing so his design input only extends to specifying the ‘Easyfit’ concept, as an attempt to induce artificial brand loyalty. All a big waste of effort if they don’t fix the design flaw though…..Huh, nobody’s going to buy a second self-jettisoning tap, just because they already have the base! As you’re offering Bristan some free suggestions for modification…..here’s one I’d suggest; I guess you’ve heard of Hozelock…..and their ‘Aquastop’ hose connectors. It’s the one with a small valve poppet inside which shuts the water off while you change attachments, same principle as a car tyre inflation valve…..That’s what Bristan need to fit inside their base to tap connector spigots, held open by coaxial actuating pins in the tap body bores, so that if the tap jettisons, the valves automatically close. But like you say, that’s fixing the symptom rather than the design flaw causing it. Oh, BTW any idea what thread is on mini mono block pipe tails? On the subject of making a company listen.......if you haven't already seen it, I reckon you'd be quite interested in this....also comprising of a set of 3 videos! kzbin.info/www/bejne/a4qqlGewhNaisNE Cheers, Allan

[@shaunjeffery4136]

Thanks for the insight into this problem ,yes it needs addressing by the manufacturer. But claims could be reduced ,as would the problems .simply by putting a warning into the taps packaging or instillation instructions stating the grub screws must be tightened or checked 6 monthly . This is not ideal but would help people like myself who have just purchased one of these taps .

[@danilodesnica3821]

Thanks, very useful. Have Bristan fixed the design flaw yet?

[@Mister_Bee]

Hi Hamish, Bertie and all plumbers (professional and amateur). I stumbled onto the tap trilogy after attending to a dripping Easyfit tap that was fitted in our kitchen in April 2019. I contacted Bristan, and 2x warranty replacement ceramic cartridges are on their way. I was unaware of the serious design flaw. Does anyone know if the issues highlighted in the videos have been adequately addressed in later versions of the tap - i.e. one bought in March 2019? Also, the original ceramic cartridges have silicone washer-type parts (blue on one, red on the other - cold and hot perhaps?). These parts were in a fairly badly worn state. What is their function?

[@CDigata]

ive just fitted one of these and it now has round holes in the base, any problems found with this 3rd base type?

[@rawcusfawcus]

Anyone experienced issues with the new design with the small holes instead of the large bevel?

[@lukebarns4859]

We fitted 2 of the cinnamon versions of this tap and 1 has failed after 10 months (luckily the customer was present when it happened). We are taking out the other tap out and not fitting any other easy fit taps.

[@tlangdon12]

If Bristan did take up your suggestions for a redesign of the Easyfit (and I hope they do), the decorative flange/union nut could potentially be tightened more than hand tight using a variety of means. One option would be to put two holes into the top of the nut such that a pin wrench could be used. A hole in the side of the nut would allow a hook pin wrench to be used.

[@smoothsilk47]

I have just messaged Bristan telling them my concerns, saying the product is not fit for purpose in its present design...I'll be interested to hear the reply, also telling them I have contacted my builder developer asking them to remove these taps from all the flats before disaster strikes. Let's hope we get some action here and not denials about the faulty fitting of this item.

[@nevillebrodie9658]

Good morning Hamish and Bertie. Been watching all three videos with interest as I fitted an Easy Fit on Tuesday. The base has changed with indents for the grub screws. Does Bertie have a stance on this, as well as yourself, obviously! Will the indent (grub shaped) now counter the upward pressure on the grub screw, from the tap? I will now need to speak with the customer.... Great work.

[@pcb1962]

Easy enough for the Bristan engineer to tell whether it's installer error - if the grub screws were done up properly there will be significant marking from the tip of the screw on the metal of the base, if there's just a light scratch then the screws weren't done up properly. I'm about to fit 2 of these, which is why I searched it on KZbin, I don't have any concerns.

[@yapproger]

Thanks for your videos on this Tap problem. I am a practical person having done lots of plumbing. I was warned earlier today that in the new flats where I live we have the Bristan Easyfit Taps. As a design modification, I was wondering if instead of having two grub screws, one long stout pin with a threaded end would be better, going right through the metal between the hot and cold pipes, then into the other side threading into the side of the chrome tap body. It would be impossible then for the top body to come of and the threaded pin would not rely on being tight.

[@HamishErskine1]

One of the important functions of the two grub screws screwing into the bevel is to tighten the tap body down onto the base as you tighten them. You could then have a third grub screw similar to what you've described that then screws into a hole in the base once the tap body is tight and correctly positioned. It need't go all the way through to the other side of the base, and I don't think there would be room for it to pass between the hot and cold. But if it simply screwed into a hole, there would be nothing to make it come lose. That might be a simpler redesign that the one I've proposed in my video.

[@robertolira9843]

Dear Hamish great videos - now 2023 and I want to install this tap BRISTAN ECHO EASYFIT MONO MIXER KITCHEN TAP CHROME do you think is OK now :)

[@davidthompson7445]

Why are Screwfix still selling these !

[@ad7219]

Hi Hamish, Just received 1901 Easyfit tap. Seems the design for grub screw fitting is different now with small indent for screw to sit in rather than the bevel/ angle. Do you think this will now be secure? Thanks

[@rawcusfawcus]

Anyone experienced issues with the new design with the small holes instead of the large bevel?

[@carolflynn1889]

I am just about to replace my kitchen mixer tap and Bristan was recommended by an acquaintance who is a plumber. After stumbling on the three videos I was wondering if they have resolved all of the issues mentioned or have they a range that is more conventional ie not with a detachable tap.>?? aNY COMMENTS FROM ANYONE WOULD BE APPRECIATED.

[@philjohnson7038]

Just watched Part 3. We definitely have the 2016 version. I have been showing my wife how to use the small alan key to check they are tight on - just in case I am not around to do so. The first thing that went through my mind when we got the new easyfit tap was to question the reliability of how two small grub screws could successfully keep the tap attached - but put that to rest by assuming all the necessary pros & cons must have been checked and crossed checked. For peace of mind a secondary (or even primary - the grub screws should be secondary) backup solution needs to be found. I understand your idea entirely but suspect that Bristan will be looking for something different - if they are looking at all now they have already altered the base configuation.

[@CivicMikey]

Heck, I wish I had found this video .. just had a Monza fitted today. Some questions:- 1. Is this still and issue with a new tap purchased in 2018? 2. Can the grub screws be held in place with Loctite? 3. If not would it suffice to check the screws every 3 months - sounds like they last 6 months - year before failure? Sorry just realised you answered 2 already.

[@Siemianowicee]

Blew-UP in my kitchen while my posh friend was helping me take caviar dish to dining room. Water everywhere, yesterday, fidelity. was bought in 2017. Water everywhere. He ingeniously found the stop cock, saved the day. We discovered this was a 2016 manufactured Bristan tap; the grub screws both had worked loose. My guest Tim, Alan-keyed it back into place while I mopped the floor, half inch of water everywhere. Nice looking tap but get inundation insurance, when you buy this handsome easy-fit tap.

[@Siemianowicee]

03/30/19 Blew-UP in my kitchen while my posh friend was helping me take caviar dish to dining room. Water everywhere. Water everywhere. He ingeniously found the stop cock, saved the day. We discovered this was a 2016 manufactured Bristan tap; the grub screws both had worked loose. My guest Alan keyed it back into place while I mopped the floor, half inch of water everywhere. Nice looking tap but get inundation insurance, when you buy this handsome easy-fit tap.

[@willdings]

Hi Hamish. this exact thing happened to us last night. Tap flew off and kitchen got flooded. Fitted about a year ago

[@Siemianowicee]

03/30/19 Blew-UP in my kitchen while my posh friend was helping me take caviar dish to dining room. Water everywhere. (tap bought in 2017) Water everywhere. He ingeniously found the stop cock, saved the day. We discovered this was a 2016 manufactured Bristan tap; the grub screws both had worked loose. My guest Alan-keyed it back into place while I mopped the floor, half inch of water everywhere. Nice looking tap but get inundation insurance, when you buy this handsome easy-fit tap.

[@roytucker9056]

Guess what, following a recent event where a tap I installed released itself and caused a lot of damage I decided to speak to Bristan to report the incident!! They immediately said it was an installer error and that my reference to these videos and proof the taps were failing was rubbish, they apparently investigated every tap installed referred to in these videos and every single installation was wrong, all were incorrectly installed. They requested a copy invoice proof of purchase and full photos of the tap base and installation!!! Guess I will be looking for a new manufacturer of taps going forward then for all my projects 😞

[@richardb7859]

Sorry about the spelling, but anyway, why is there only one cheep grub screw holding the top on. There could easily be three. I also agree with Hammish regarding the shamfer. It should be a groove. My new Grohe is a bit more expensive but worlds apart.

[@ptuk3700]

Good Video Hamish and I came across your video by accident looking for a solution for getting more rigidity on a Bristan Kitchen Tap - Possible quick fix, but Andy the installer thinks there is not enough room in the threaded holes, could be to have an extra grub screw to piggyback the first ones tightened onto the base. This way is creating a lock nut as extra friction is pushing against each grub screw in the same thread reducing the chance of the grub screw/s coming loose...?

[@HamishErskine1]

Hi Darrel, I agree with Andy that the thickness of the thread in the tap body in insufficient to allow for a second grub screw. Locktite 243 would probably work to make an existing installation secure. But for anyone who has just purchased an Easyfit tap, I would recommend returning it for a refund and fitting a non-Easyfit tap instead. If an Easyfit tap fails when you are out, or in the middle of the night, it could cause thousands or even tens of thousands of pounds worth of damage. These taps are simply not worth the risk. If you search for kitchen mixer taps on Amazon, there are some excellent alternatives. I especially like the Vapsint taps which are massively reduced on Amazon and are a nice sturdy design.

[@ptuk3700]

Hi Hamish A forum member has made the following comment who mention your videos and yourself - "I've been to see the customer this morning and had my supplier speak to Bristan. They are aware of this video and know that the ones he fitted where they blow of were fitted with the base plate the wrong way round. Bristan have changed the fitting now so that it's impossible to fit them the wrong way round. I am going back on Friday though to put some loctite on the grub screws.

[@HamishErskine1]

Hi Darrel, yes in this video (Part 3) I show the new base design alongside the original, and illustrate how Bristan have fixed the issue of 'installer error', ie. the possibility of fitting the base the wrong way round. The base-orientation issue relating to the original base design was a relatively minor flaw, in my opinion, compared to the design flaw that still causes the grub screws to gradually work loose on correctly installed taps. This flaw hasn't yet been corrected and still affects their current range. Bristan have tried to cover up the grub-screw loosening problem by blaming it all on the base-orientation problem. But these are two separate design flaws. They fixed one, but not the other. You say in your comment that Bristan 'are aware of this video and know that the ones he fitted where they blow off were fitted with the base plate the wrong way round'. If that is what Bristan are actually saying about the taps I had problems with, then they are unashamedly lying through their teeth. They know fine well that is not the case.

[@arnoldrimmer9161]

Who's ever noticed that this type of fixing on wall mounted accessories that are subject to vibration and usage like toilet roll holders etc (as in a grub screw winding down on a beveled surface) soon become loose. I'm an average Joe with poor to average school grades but if I was asked to fit one of these taps I would think twice, it would just seem too obvious to me that over time it would work it's way loose and I would suggest to the customer to pick another tap. Just as an extra I would definitely use some type of threat lock though, my rc helicopter has rotors that spin at 24000 rpm and experience some serious vibration have never come loose thanks to threadlock, and are relatively easy to undo and change too.

[@user-sg1ku5hu5d]

The simple fix is to form the cone shape end of the grub screw as a square or hex. this would fix all existing taps by simply supplying new grub screws...

[@richardb7859]

Thank God I saw this. I was not impressed with my easy fit tap because it started dripping again, and the swivel has always been really stiff. I had already replaced the valves once, and it was Not old. Seeing the taps pop off made me deide to change the whole thing rather than mess around. I bought a new Grone Swan neck tap. On removing my Britan Easy fit bace I found that the grub screw wax loose. One full turn if it and the top came off easily. I was lucky it had not blown off. As an engineer I can say that this design, with a single point failure is, what is known in the trade, as really shit.

[@davidthompson7445]

I bought this model so that i could fit it myself ( I'm a retired aerospace engineer ) . Glad i found your videos ! The base of mine looks different ( again ) and bears the description JL1019 . Haven't a clue as to its' "worth" . Is this instead of the word "front" ? If it had read 2019 I would have taken this to be JULY (JL) 2019 ? This base has no bevels but instead 4 slighlty co-bored holes which I would have imagined to be for 4 grubs screws to wind into ? The actual tap body has 2 grubscrews in it . Hamish , dare I proceed and fit the unit ? My old kitchen mixer tap has "had it " and ringing around i can't get an actual plumber or bathroom fitter to "fit me in " before XMAS ! HELP !!!!!!!!!!!!!!!

[@Malcarper]

I have just bought the same model dated JL 09 20 . Mine also has 2 grub screws in the tap body and 4 co-bored holes in the base. I think the idea is you can you fit the base in one of two position, by turning it 180 degrees. This is supposed to be the latest version, that should stop the top from popping off the base. I'm not convinced and seriously thinking about drilling 2 extra holes / tapping a thread in the tap body , to accept 2 extra grubs screws. Result will be 4 grub screws, in to 4 co-bore holes in the base.

[@joolsmartin1996]

They have now modified design

[@yapproger]

The reply I just had from Bristan, doesn't really give me any more confidence, as even if the tap screws were fully tightened, screws can work loose, if this happened in most taps there would not be a catastrophic flood, more of a slow leak! It is a design weakness which needs modification! Good Morning Case reference 01018103 (Bristan - New enquiry) Thank you for your email. We can confirm that you should have no problem with the Bristan Easyfit taps as long as they have been fitted as per the fitting instructions that are supplied with the taps. We have been made aware of instances, like the ones mentioned in the video, where the taps have blown off the Easyfit base. When Bristan engineers have attended these properties it has been found that they were not installed correctly and this is what had caused the problem. In these instances the taps were not fully pushed onto the base before the screws were tightened or in some cases the base was fitted the wrong way round although it did have 'FRONT' on the base. Bristan have changed the design of this base to make it easier and more fool proof for installation as it now does not matter which way around the base is fitted. We hope this has allayed any fears. Regards Joanne Fear

[@HamishErskine1]

John, I absolutely agree with you. If a failure started with a slight leak it wouldn't be such a problem. It's the fact these taps fail so catastrophically without warning that makes them such a serious flood risk to people's homes. In addition, when they fail you have potentially scalding water coming out of the hot side and bouncing off the ceiling, so when you reach under the sink to turn off the mains you could get badly scalded. As for their reply - an unfortunate sign-off and surname. Unfortunately it doesn't ...(allay any fears). Bristan engineers replaced the taps for a number of my customers after I published my first video last September. Three of those had previously blown off and been reattached by me. They never gave me any followup feedback or accused me of having fitted any of them incorrectly, and I am sure none of them had been. Neither of the above two mis-fitting examples were applicable. The grub screws had simply loosened over time, but they don't admit that as one of the possible reasons for taps blowing. As I've explained in another comment, such an admission would lead to a recall, and having sold 4 million Easyfit taps, a recall would cost them something in the region of £500 Million. So don't expect things to change any time soon. Just tell any plumbers you know not to fit them. And now that Bristan have said that applying loctite would invalidate the warranty, you can't do that either because you would transfer any potential liability from Bristan to yourself.

[@timbunker4529]

Glad I didn't use one now when we did the kitchen!

[@simonpidgeon949]

💯👍👍

[@neilhunt7895]

I am and I will take them out, might be able to salvage something out of a bad job !!!!! Still it won't be worth the £87 I paid for the tap

[@HamishErskine1]

Currently my favourite kitchen taps are made by Vapsint. You can get them heavily discounted on Amazon, so no need to pay £87 for a tap. £40 to £50 price range is much better, and they don't flood people's houses.

[@xinyuinternational]

The quality of this product is really bad, hahahaha.

[@lukebarns4859]

We fitted 2 of the cinnamon versions of this tap and 1 has failed after 10 months (luckily the customer was present when it happened). We are taking out the other tap out and not fitting any other easy fit taps.

[@HamishErskine1]

That's interesting. Back in August, Bristan assured me they hadn't had any problems with the Cinnamon. Have you been in touch with Bristan about this failure? I suspect one of the problems with these taps is that not enough people report back to Bristan about them.

[@lukebarns4859]

We waited on the phone for 20 minutes to the customer service team but didn't manage to get through. We took it up with our supplier (plumbase) and they were chasing it up. Both taps were changed today. First one (one that blew off and was reseated 1 month ago) had a loose grub screw again, the other was solid. The first tap was into a thin stainless steel sink and had flex, the other was into a solid worktop. I believe that this was the main culprit for the grub screw movement. Both 2015 versions.

[@HamishErskine1]

Personally I don't think the solidness or flexibility of the worktop is what makes the difference. I believe it is the pressure jolt that occurs when you turn the tap off. I also think there's a degree of randomness and bad luck as to how quickly the grub screws work loose. I would encourage you to persevere with Bristan's customer services. They are still selling these taps, and the more people report the problem to them the sooner they are likely to issue a general recall.