Gledhill Stainless Lite Indirect

[williams85]

I too have been having trouble with a Gledhill unvented indirect cylinder, which I installed last summer and haven't been able to resolve!
The symptoms sound pretty much like what has been described on here.
A loud bang/crack from the cylinder when a hot tap is run but not all the time, there seems to be no pattern?
I connected Gledhill about this and they said they have never come across this, one suggested extra expansion vessel which i did but made no difference.
I then had the cylinder changed for a new one from Gledhill which started to run fine but then after about 1 month of use, the same problem came back!
The cylinder was tested and found to be no issue with it...
Now Gledhill say it must be an installation fault or design fault? Ive installed many cylinders and this is the first that has caused problems, so Im a little stumped on what it could be and the next step?
Would really like to know how you get on with Gledhill and what they might suggest?

 

[socdesign]

Funny, we too contacted Gledhill and they've said that they have "never seen this before". They also suggested an extra expansion, but as the bangs are happening at lower pressures, then the plumber said that didn't sound right. Our cylinder also seems to rattle inside if you nudge the coil outlet pipe!

I'm probably a stage behind you! Gledhill do not have anyone who can look at the cylinder, so we have to swap out and return.

I'm beginning to think that I should cut my losses and get a different make of cylinder fitted! I hate to think that this can go on indefinitely.

What are the working/standing pressures on the system ? I'd be interested to hear if they're similar to mine.

 

[williams85]

The time when it was first happening, Gledhill had said they couldn't send anyone out to have a look because I had got the cylinder from my merchants at a good price so can't afford too!! which i think is a joke!!
I was out of ideas on what it could be so my only conclusion was to have the cylinder exchanged for another one, which Gledhill agreed to at no expense to myself. Sadly the problem was the same with the new cylinder.
The latest now is that Gledhill can send an engineer out but at a cost and there is no guarantee that the problem will be resolved. They recommend the installer (me) at finding the problem.....
I cant remember the exact figures for the standing/working pressures to be honest, with it being last year. I will be going back to the property in question soon to see about a solution so will check the pressures again

 

[mickyg]

i checked the manual and surprisingly there is no min dynamic pressure that I can see unless i have missed it. Megaflo state min 1.5bar, and most others state something similar.
If you want to stop it try fitting a 1.5 or 2 bar pressure reducing valve before the manf combination valve.

 

[williams85]

Thanks for the advice mickyg
Is this something you have experienced before?

 

[mickyg]

Thanks for the advice mickyg
Is this something you have experienced before?

no im just a smarty pants

 

[socdesign]

If you want to stop it try fitting a 1.5 or 2 bar pressure reducing valve before the manf combination valve.

We have a pressure reducing and non return on the incoming to the house prior to the 22mm going to the combination valve. It's adjustable, so I can turn it down. We had it turned down before, but I don't think to anything as low as 1.5. At this rate, the pressure is going to be the same as the old vented cylinder. I'll give it a go though.

 

[mickyg]

If you want to stop it try fitting a 1.5 or 2 bar pressure reducing valve before the manf combination valve.

We have a pressure reducing and non return on the incoming to the house prior to the 22mm going to the combi valve. It's adjustable, so I can turn it down. We had it turned down before, but I don't think to anything as low as 1.5. At this rate, the pressure is going to be the same as the old vented cylinder. I'll give it a go though.

well if it works you will at least confirm the diagnosis

 

[socdesign]

That's it turned down now. Ran all the hot water out and have now started the boiler up. I'll post the results tomorrow.

 

[williams85]

I hope it works.........
look forward to hearing how you get on

 

[socdesign]

Didn't work! Two loud bangs from the cylinder this morning.

Next step cylinder replacement and if that doesn't work, then I've no choice but to rip it out and put something else in.

I have to say that if it had worked, I don't think your customer would have been that happy with the water pressure anyway.

 

[mickyg]

what pressure reducing valve was that ? and does it have a gauge? The cheap ones only seem to reduce pressure in flow and don't lock up, basically useless.

 

[socdesign]

Looks like this one, but I need to verify the make. The gauge isn't fitted to it at the moment, it's fitted up on the hot water circuit, as I've been trying to understand the pressures that the cylinder is banging at.

http://www.builderdepot.co.uk/altecnic-22mm-pressure-reducing-valves-and-gauge.html

 

[williams85]

Shame it didn't sort the noise out......
Yes I agree that the customer would not think too much about the lower pressure setting.
So you've put the pressure reducer on the out going hot?

 

[williams85]

Have you tried reducing the pressure of the expansion vessel?