Vibrating hot water return pipe from indirect cylinder

[Antony001]

Hi,

I have two indirect water cylinders (Gledhill) connected to a gas boiler (Vaillant). The system is setup/programmed so that the tanks heat up twice a day for about 2 hours. When the tanks start to heat, one of them makes a loud vibrating noise, sometimes for about 15-20 mins, sometimes for longer. The noise seems to be coming from the hot water return pipe (i.e. the pipe taking the hot water back to the boiler). If I hold that pipe (it has insulating foam) tightly close to the cylinder then the noise stops.

This has been happening since we moved into the property about 9 months ago. I was worried that it's getting louder, but my wife thinks it's the same as it always was.

I was wondering if anyone can tell me ...

• What is the likely cause?
• How much do I need to worry? We're booked for a service in a couple of months anyway so could just get our plumber to look at it then, but do we need to get him out sooner?

Many thanks,
Antony

 

[John.g]

Are they Gledhill Lite cylinders?.

 

[Antony001]

Are they Gledhill Lite cylinders?.

Yes ... Gledhill StainlessLite

 

[John.g]

There have been numerous posts about these, have a look at this......

Search results for query: gledhill lite problems

www.plumbersforums.net

and

Cylinder noise / Balanced Colds / Pressure etc

I wanted to start a new more dedicated thread as I am on about 3 just now in one way or another trying to get up to speed with my problem. The issue is that my Gledhill Stainless Lite indirect unvented cylinder makes loud noises when heating - this is a bit random, but that noise is loud enough...

www.plumbersforums.net

 

[ShaunCorbs]

Too much flow through the return needs a lockshield gate valve fitting on the return from each cylinder 100% will fix the problem

Leave them fully open turn the boiler on to heat one up at a time and slowly close the lockshield gate valve until the vibration stops should be around 4-5 full turns etc