Loud Buzzing Noise From Cylinder Driving Us Crazy!!!

[WSB]

Hi All,

Had my old Baxi Bermuda back boiler system completely replaced with Boxt in Feb this year.

Had a conventional Worcester Bosch Grenstar Ri fitted with new cylinder and new rad TRVs and piping etc.

All was good until Sept when we were woken when the hot water heating came on in the morning and there was this terrible very loud humming noise coming from the hot water storage cylinder. It was doing this intermittently every time the hot water heating came on.

After various Boxt sub contractor heating engineer visits, it was eventually diagnosed that the issue was a rare manufacturing fault within the hot water storage cylinder, whereby the coil inside came lose.

Two weeks ago, this cylinder was replaced under warranty and all was well apart from the CH zone valve being stuck such that when the hot water heating came on, the CH also comes on Very annoying! Contacted Boxt who said that they would send someone in the New Year to replace that valve (not been fixed yet).

However, 2 days ago, less that 2 weeks after having the new cylinder fitted, we are getting the same terrible loud humming noise from the cylinder when the hot water heating comes on.

Driving us mad!!!!

Any advice much appreciated.

 

[Razor900]

Is it a Gledhill cylinder by any chance?

It probably needs a valve on the return to throttle the amount of water going into the coil. Corrugated coils are notorious for it

 

[WSB]

Is it a Gledhill cylinder by any chance?

It probably needs a valve on the return to throttle the amount of water going into the coil. Corrugated coils are notorious for it

Thank you. That's very interesting and helpful. Yes, the first cylinder was a Gledhill. Not sure about the second one. I'm guessing it is as well. Not sure if this is relevant but the original was green and the new one is blue.

So when you say "It probably needs a valve on the return to throttle the amount of water going into the coil" is water being shoved into the coil at too fast a rate?

Sorry, but what is a corrugated coil?

Also, any idea why this problem would occur 6 months after original installation?

Thanks!

 

[Johntheo5]

The circulation flow rate through the coil may be too fast, this can be slowed down by installing a (normally) gate valve on the coil return and then throttling this to say a 1/2 to 1 turn open, it may, but only my, help.
A corrugated coil is a coil with corrugations, gives better heat transfer than a smooth walled one.
Can you have a look at your blue cylinder and post or take a few photos of its labelled details??

 

[dilalio]

Is it a Gledhill cylinder by any chance?

It probably needs a valve on the return to throttle the amount of water going into the coil. Corrugated coils are notorious for it

If BOXT always use gledhills, you'd like to think they'd have learned this by now!

 

[WSB]

The circulation flow rate through the coil may be too fast, this can be slowed down by installing a (normally) gate valve on the coil return and then throttling this to say a 1/2 to 1 turn open, it may, but only my, help.
A corrugated coil is a coil with corrugations, gives better heat transfer than a smooth walled one.
Can you have a look at your blue cylinder and post or take a few photos of its labelled details??

Strange that it took 6 months for noise to occur on original cylinder and only a couple of weeks to occur on the new cylinder. Will attach video below in this thread.

 

[WSB]

If BOXT always use gledhills, you'd like to think they'd have learned this by now!

Making me think that the problem is something else

 

[WSB]

Sorry, can't attach video as file too big

 

[Johntheo5]

Your WB RI boiler should/will have a external circ pump?, can you post details of its make/model/mode/setting and/or a close up photo of its LEDs while running, may be able to reduce its head which might reduce noise level.