Sealed System Worcester Bosch Boiler With Banging Noises in Storage Cylinder

[WSB]

Have a 6 month old Sealed System Worcester Bosch 4000 Ri Boiler system with Storage Cylinder.

When it heats water or rads, getting banging noises from the hot water cylinder.

Got engineer coming to look at it (under warranty) in a couple of days but wanted to be clued up as to what the issue could be and what he possible needs to do to rectify it.

It's only 6 months old and only had this issue in last 2 months, not prior.

Had engineer visit 2 weeks ago who repressurised the system and bled the rads but have the same problem again.

Back then the boiler stopped working.

Now it works as in heats water and rads but am still getting these banging noises in the storage cylinder again.

Any thoughts and suggestions greatly appreciated.

Thanks in advance.

 

[Johntheo5]

Is this HW storage cylinder a unvented cylinder with a external expansion vessel, what make and model is the UV cylinder?.

 

[WSB]

Is this HW storage cylinder a unvented cylinder with a external expansion vessel, what make and model is the UV cylinder?.

Thanks. Yes, it's an unvented system with an expansion vessel in the same downstairs cupboard as the boiler. Not sure of the make and model.

 

[Johntheo5]

If a S system which will have a separate 2 port motorised valve on the HW heating coil to the HW Cylinder, ensure the arrow on the valve body is pointing into the. Cylinder, this assumes that to top connection is the coil inlet.

 

[WSB]

If a S system which will have a separate 2 port motorised valve on the HW heating coil to the HW Cylinder, ensure the arrow on the valve body is pointing into the. Cylinder, this assumes that to top connection is the coil inlet.

Got the Boxt appointed engineer coming out on Saturday as it's still under warranty.
Had it installed end of Feb this year. Has taken till Oct to get this problem.
We used the central heating for a few months after installation without any issues.
Over summer just had it to heat the hot water.
Started getting these noises in early Oct, long before we started using central heating again.
Just don't understand how something so new can go wrong after working fine for over 6 months.
NB: This boiler job was quite a big refit as was replacing an old Baxi Bermuda back boiler system.

 

[dilalio]

What make is the UV?

 

[WSB]

Ok, so the Boxt appointed engineer came out.
Good bloke who carried out a thorough investigation.
Upshot was it was the coil pipe inside the hot water cylinder come loose.
Of course, no way to fix that other than to replace the whole cylinder.
He said he'd only ever seen that issue once.
I'm guessing maybe the cylinder had got damaged somehow by being dropped at some point.
Don't know. Boxt are getting it replaced under warranty so all good.
Is this problem common? Doesn't sound it.

 

[CountryFan]

Is this problem common? Doesn't sound it.

I wouldn’t have thought so. First time I’ve heard of it today.

 

[Johntheo5]

I think some coils are now flexible and are on hangers of some sort or other, unlike the rigid copper coils which are very unlikely to go banging about. The cylinder make might throw up something in its MIs.

 

[dilalio]

Yes. Be interested to know make and model.

 

[WSB]

Yes. Be interested to know make and model.

It is a Gledhill cylinder, vented to loft cold tank (450x1050).