Gledhill Unvented Cylinder Loud Bang Hot Water Demand

[Adam-Robinson]

Recently had a new heating and hot water system retrofitted in a domestic property. Previous hot water system was gravity fed with a vented cylinder. New system as shown in the photos. Installer commissioned system about 3 months ago and all was working fine.

There have since been two faults:

1.) About 6 weeks ago the pressure relief pipe came off inside boiler, large amount of water leaked from the boiler, cause was a faulty thermostat on the Gledhill cylinder. Damage caused to boiler as PCB was beyond repair.
2.) Within the past 4 weeks the Gledhill cylinder has developed a popping sound whenever there is demand for hot water. This has now got to a volume that is alarming if standing near the cylinder. I've attached a video of this happening.

Could an experienced and G3 registered plumber provide opinion on the overall installation as shown in the pictures - do we have a sound installation or are there signs of a sub-standard job? I would also appreciate any thoughts on what could be causing the loud popping sound coming from the cylinder.

Any comments gratefully received.

 

[Scott_D]

Is the noise when you draw off hot water or when it’s heated?

 

[Adam-Robinson]

Is the noise when you draw off hot water or when it’s heated?

Hot water draw off.

 

[Scott_D]

Have you asked the installer to check it over?
If the secondary hot return is a long run the expansion may be undersized

 

[Adam-Robinson]

Installer has been asked to check it over however has yet to come on-site, his current thinking is back pressure through a mixer tap which requires a pressure reducing valve fitted above the stock cock or a check valve on the offending hot pipe.

 

[Scott_D]

Could be a few different things.
Best to get the installer out. If they won’t/can’t find the cause you may have to pay another installer or call in the manufacturer

 

[samba1]

Installer has been asked to check it over however has yet to come on-site, his current thinking is back pressure through a mixer tap which requires a pressure reducing valve fitted above the stock cock or a check valve on the offending hot pipe.

I have the same issue on same cylinder (210litre version), what was your resolution?

 

[Adam-Robinson]

I have the same issue on same cylinder (210litre version), what was your resolution?

PRV fitted above main stopcock appears to have resolved the issue. Still slight pops when hot water is drawn off but nothing compared to the original post, certainly nothing that makes me jump when next to the cylinder! Installer has stated the popping noise is the movement of insulation due to expansion/contraction within the cylinder and nothing to worry about.

I'll be interested to hear about your resolution.

 

[EvilDrPorkChop]

Sounds like they're s*** cylinders, think i'll stay away from them 😂 Never been a fan of Gledhill

 

[John.g]

I have the same issue on same cylinder (210litre version), what was your resolution?

Did you ever get a pressure gauge installed at the cylinder?? Both the OP's installer and Shaun Corbs, in your thread, reckon its the insulation, if so, maybe no big deal apart from noise?.

What is the advantage of these "lite" cylinders, presume its to enable the installation of a bigger volume cylinder (+25 litres or so) and not require extra floor reinforcement?.

 

[samba1]

Did you ever get a pressure gauge installed at the cylinder?? Both the OP's installer and Shaun Corbs, in your thread, reckon its the insulation, if so, maybe no big deal apart from noise?.

What is the advantage of these "lite" cylinders, presume its to enable the installation of a bigger volume cylinder (+25 litres or so) and not require extra floor reinforcement?.

Hi, no still waiting for Dyno to return. I think my situation is different, the noise is really loud, it’s like someone taking a hammer and smacking the cylinder hard. It’s shockingly loud when water is drawn. I feel, it could be the cylinder flexing in and out like a plastic water bottle, and I suspect that the combination valve is faulty as it sounds like an aircraft when any hot water tap is turned on. It could be a sticking combination valve that is causing the loud bang, but because they’re so close to each other it’s difficult to gauge. I think I really have 2 issues, because the bangs are of different amplitudes, one is the combination valve and the other is the cylinder, both making shockingly loud noises. I could be wrong. The cylinder does have an 8 inch crease on the outside (which was present when supplied and dismissed as being cosmetic), and I see my cylinder serial number sticker has been placed over an older serial number (with a lower number), which says to me I have re worked (of even a returned) unit. All very suspicious?? The cylinder, EV and combination valve was supplied by Gledhill. Neighbour has exactly the same cylinder, EV and valve (also fitted by BG/Dyno). It’s silent, even when water is drawn, which is how my old cylinder and valves behaved before being replaced with a Gledhill lite. I think I have a lemon considering all the factors.

I really don’t know, but others have said they are lite, because they’re 10kg lighter than others so perhaps their internal cylinder wall are thinner, I see other manufacturers say their internal cylinder wall is 40% thicker steel, and their specs show an empty weight of around 45kg, whereas the Gledhill lite is about 33kg for a 210L.

 

[John.g]

Could be a sticking combination valve all right, the hot water flow might be a bit erratic if it is.
Has your neighbour got the balanced cold taken from the combination valve?, or did BG/Dyno install it like yours where the cold and hot are taken from two different PRVs, not that that shouldn't work OK, as probably dozens of cylinders plumbed in like that.

 

[samba1]

Could be a sticking combination valve all right, the hot water flow might be a bit erratic if it is.
Has your neighbour got the balanced cold taken from the combination valve?, or did BG/Dyno install it like yours where the cold and hot are taken from two different PRVs, not that that shouldn't work OK, as probably dozens of cylinders plumbed in like that.

Yep, plumbed exactly the same as mine, no balanced cold taken either. Both houses pretty much the same too with identical mixer showers. Only difference is that his pump is the previous model, mine is Grunfos UPS3, which was only replaced very recently.

 

[samba1]

Yep, plumbed exactly the same as mine, no balanced cold taken either. Both houses pretty much the same too with identical mixer showers. Only difference is that his pump is the previous model, mine is Grunfos UPS3, which was only replaced very recently.

Folks, I thought I’d try to close this problem off, the resolution in my case was a replacement cylinder (not Gledhill, but Joule), and no more banging. The expansion vessel was replaced with same make and model, and the combination valve was replaced with a Caleffi this time (not Reliance Water Controls), personally I feel there were 2 things at fault. The cylinder (which I suspect was a factory rework - as it had a new serial number stuck on top of the old one) and the combination valve being defective in some way.

Thanks to all that offered advice and guidance.

 

[Jurgen Klopp]

I have this issue with the 300 litre Gledhill Stainless Lite. After nearly 8 months of emails and calls to Gledhill I will be getting a new cylinder next week. The problem is that in order to produce more cylinders, Gledhill reduced the drying time for the foam from 21 minutes to 16 minutes and this is where the problems started. All cylinders made at that time have developed the banging noise, they have now gone back to a 21 miute drying time. They will try to resolve the issue by riveting the skins together but who wants rivets on a brand new cylinder ?1?!
If you have this problem tell them you want a new cylinder and demand the £120 call out charge be returned because it is not an installation issue, it is a Gledhill issue.

 

[samba1]

I have this issue with the 300 litre Gledhill Stainless Lite. After nearly 8 months of emails and calls to Gledhill I will be getting a new cylinder next week. The problem is that in order to produce more cylinders, Gledhill reduced the drying time for the foam from 21 minutes to 16 minutes and this is where the problems started. All cylinders made at that time have developed the banging noise, they have now gone back to a 21 miute drying time. They will try to resolve the issue by riveting the skins together but who wants rivets on a brand new cylinder ?1?!
If you have this problem tell them you want a new cylinder and demand the £120 call out charge be returned because it is not an installation issue, it is a Gledhill issue.

Funny you say that. When the Dyno engineer called Gledhill for advice, he normally expected them to go though a set of fault diagnosis steps. He was surprised that they didn’t engage in that dialogue and instantly said they’d send a Gledhill engineer out. He felt that Gledhill knew about this issue. Your post just reinforces and confirms the suspicion!

 

[Poiuytr]

Jurgen / Samba - apologies for jumping on an old thread - I too am having issues with noise with a Gledhill Stainless Lite Indirect 150L - the noise is made when the cylinder is heating up rather than drawing (though there may be some noise after a shower has been taken also) so may be different from you guys - but the noise is like a metalic/plastic hybrid bang when it goes off - the bang is not every time it heats up though so is quite hard to replicate. (John G is kindly being of assistance on a separate thread)

My Gledhill was installed Feb 21 from a manufacturing date in Jan 21 - I was wondering if you knew when the issue with these cylinders was meant to be around, and also, on the replacement with the Joule cylinder if BG/Dyno arranged and covered this for you.

I am keen to try and move on with mu current issues as they have been ongoing for a while now so any info you could provide would be of great help as somehow with BG/Dyno will have to figure out whats going on, or Gledhill for that matter.

Many thanks

 

[samba1]

Jurgen / Samba - apologies for jumping on an old thread - I too am having issues with noise with a Gledhill Stainless Lite Indirect 150L - the noise is made when the cylinder is heating up rather than drawing so may be different from you guys - but the noise is like a metalic/plastic hybrid bang when it goes off - the bang is not every time it heats up though so is quite hard to replicate. (John G is kindly being of assistance on a separate thread)

My Gledhill was installed Feb 21 from a manufacturing date in Jan 21 - I was wondering if you knew when the issue with these cylinders was meant to be around, and also, on the replacement with the Joule cylinder if BG/Dyno arranged and covered this for you.

I am keen to try and move on with mu current issues as they have been ongoing for a while now so any info you could provide would be of great help as somehow with BG/Dyno will have to figure out whats going on, or Gledhill for that matter.

Many thanks

In my case, Dyno heard it and so there was no doubt that the issue was abnormal. It is a shocking noise, and I do feel for people like you as it ruined my Christmas and the weeks following it. If you have had it installed, then just say you want it replaced. I have read that Gledhill know about the issue and some report that it is to do with the time the insulation material is allowed to “dry” - which has been reduced by many minutes. I have read that Gledhill fix the issue by riveting the skins together, not sure how they do it but who wants rivets on a new cylinder face?

If in your case Dyno/BG installed it, then get them to replace. Initially Dyno were going to order a replacement of the same and I said no thanks. I did a little research and I went for Joule because the technical guys there said they use 1mm stainless steel skin whereas others tend to use 0.5mm stainless skin.

I don’t know if I have answered your question but I hope my experience and suggestion is if use?

 

[Poiuytr]

Samba - thank you so much for this. The issue has been going on for some time now and BG/Dyno have not so far been able to resolve - despite being able to play them audio files etc - they have changed valve around the MV, adjusted bypass (which helped to an extent) - but the problem keeps coming back. The loud noise was heard by an independent G3 who did the annual service and suggested I speak to Gledhill - I am doing this (but certainlty wont be accepting a riveted cylinder - though I'd consider it if they offered to replaced and install in full) in conjunction with more observation and then another conversation with BG/Dyno slightly further down the line - either way, someone needs to resolve and it shouldn't be me - unfortunately this means I am still chasing around after a few months of this.

I am sorry that your Christmas and weeks after were ruined - I know exactly how you are feeling having put up with this through the Winter months - now I just need it to be brought to a solution.

Thanks again and hope your Joule cylinder continues to bring you the silence you deserve.

 

[samba1]

Samba - thank you so much for this. The issue has been going on for some time now and BG/Dyno have not so far been able to resolve - despite being able to play them audio files etc - they have changed valve around the MV, adjusted bypass (which helped to an extent) - but the problem keeps coming back. The loud noise was heard by an independent G3 who did the annual service and suggested I speak to Gledhill - I am doing this (but certainlty wont be accepting a riveted cylinder - though I'd consider it if they offered to replaced and install in full) in conjunction with more observation and then another conversation with BG/Dyno slightly further down the line - either way, someone needs to resolve and it shouldn't be me - unfortunately this means I am still chasing around after a few months of this.

I am sorry that your Christmas and weeks after were ruined - I know exactly how you are feeling having put up with this through the Winter months - now I just need it to be brought to a solution.

Thanks again and hope your Joule cylinder continues to bring you the silence you deserve.

Samba - thank you so much for this. The issue has been going on for some time now and BG/Dyno have not so far been able to resolve - despite being able to play them audio files etc - they have changed valve around the MV, adjusted bypass (which helped to an extent) - but the problem keeps coming back. The loud noise was heard by an independent G3 who did the annual service and suggested I speak to Gledhill - I am doing this (but certainlty wont be accepting a riveted cylinder - though I'd consider it if they offered to replaced and install in full) in conjunction with more observation and then another conversation with BG/Dyno slightly further down the line - either way, someone needs to resolve and it shouldn't be me - unfortunately this means I am still chasing around after a few months of this.

I am sorry that your Christmas and weeks after were ruined - I know exactly how you are feeling having put up with this through the Winter months - now I just need it to be brought to a solution.

Thanks again and hope your Joule cylinder continues to bring you the silence you deserve.

If you’re with BG then call them out and if no joy in replacement, raise a complaint. In my case it was an immediate problem. The evidence is too great for them to ignore. Only sticking issue for you is that it has been a little while since the install. Gledhill know about the problem, you can call them directly as the product warranty covers you for that. If you mention noises etc they will know precisely the issue. When they propose a riveting solution you say no, and then tell BG, the fix is not acceptable so let them battle with Gledhill. BG are a big customer of Gledhill so they won’t want to ruin that relationship for a few hundred quid. It’s an absolute pain in the rear this… some guy must have thought he’s saving the company loads of money on reducing the production line times by shortening the drying times… this is the price we pay, and eventually Gledhill will pay as people will just avoid their products…

 

[Poiuytr]

I suspect the issue has been longer running to be honest - maybe since install last Feb - I used to have the HW on during the night (with a short top up during the day) but changed the timings a while ago and this is when I first started hearing the noise - though I would say that used to wake up during the night so everything could be linked back to install date. BGs cover suggests that they replace if they cant fix it and there is clearly an issue here, not just for me, but others with Gledhill cylinders - having it replaced by BG (for another brand) would be my preferred solution - my previous Santon Premier ran until it eventually started leaking after many years of just sitting in the airing cupboard minding its own business. If they have fixed their drying times then it may be that a Gledhill replacement will work as and when down the line. I'd rather not pay for a replacement myself and dont think I should either.

 

[Poiuytr]

Watched back OPs video from June... noise is similar here - and also ties back to noise that is sometimes made at some point after shower usage here. I'm not quite sure I buy the line that this is just movement through contracting etc - am sure that cylinder make some kind of noise, but surely not that?

 

[GLEDHILLSUCKS]

Hi All.

Just came across this thread.

Firstly thanks for the info, it's been useful and has confirmed there is an issue with this cylinder. I am sure I read it last year, but since then, things have gone south again

Had a full system replacement, from gravity fed to unvented, new boiler etc March 2021.

Problems started almost immediately where my bathroom installer noticed the tank was leaking.

I called out the plumber who installed the system and the tank was replaced free of charge August 2021.

Since then, I have had no leaks, however I have been experiencing a loud bang from the cylinder. I've noticed this happens whenever the tank is heating up. If hot water is off, it seems to be fine. This bang has got worse over the last couple of months and is worrying to say the least as it can be heard throughout the house.

I am now experiencing a loud juddering sound when drawing hot water from the cylinder. This only happens after the tank has been heated, not after initial draw off or of the water is not being heated.

 

[Poiuytr]

Hi All.

Just came across this thread.

Firstly thanks for the info, it's been useful and has confirmed there is an issue with this cylinder. I am sure I read it last year, but since then, things have gone south again

Had a full system replacement, from gravity fed to unvented, new boiler etc March 2021.

Problems started almost immediately where my bathroom installer noticed the tank was leaking.

I called out the plumber who installed the system and the tank was replaced free of charge August 2021.

Since then, I have had no leaks, however I have been experiencing a loud bang from the cylinder. I've noticed this happens whenever the tank is heating up. If hot water is off, it seems to be fine. This bang has got worse over the last couple of months and is worrying to say the least as it can be heard throughout the house.

I am now experiencing a loud juddering sound when drawing hot water from the cylinder. This only happens after the tank has been heated, not after initial draw off or of the water is not being heated.

Hi All.

Just came across this thread.

Firstly thanks for the info, it's been useful and has confirmed there is an issue with this cylinder. I am sure I read it last year, but since then, things have gone south again

Had a full system replacement, from gravity fed to unvented, new boiler etc March 2021.

Problems started almost immediately where my bathroom installer noticed the tank was leaking.

I called out the plumber who installed the system and the tank was replaced free of charge August 2021.

Since then, I have had no leaks, however I have been experiencing a loud bang from the cylinder. I've noticed this happens whenever the tank is heating up. If hot water is off, it seems to be fine. This bang has got worse over the last couple of months and is worrying to say the least as it can be heard throughout the house.

I am now experiencing a loud juddering sound when drawing hot water from the cylinder. This only happens after the tank has been heated, not after initial draw off or of the water is not being heated.

Hi there. I too had an issue with the banging. As noted there seems to have been an issue regarding a batch of these cylinders. Times of manufacture differ and my understanding is that new cylinders are not affected but I dont know this - but the install date is not what matters here as there will be cylinder lying around storage at merchants etc.

In my instance, after much investigation by myself, BG/Dyno and rmuch eference to this excellent board I approached Gledhill directly on the issue. They inspected and advised that the repair was to rivet the outer skin - the rivet is at the back of the cyilinder so this will not affect any asthetics. I have heard some reports that this does not work, but so far, (very much) fingers crossed, two months after the repair, the banging has gone. Should it come back I would simply contact Gledhill again. The issue was noise of the casing during expansion and contraction. I would advise that, in consultation perhaps with your installer, that you speak to Gledhill on this matter.

I fully understand your concerns here, it is a very loud noise but hope that my reply will assist you in some way.

All the best.

 

[Lou]

(Just bumping a few older threads, they will drop off what is new soon)

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