vaillant turbomax judding / moaning on hot water

[simonjay]

Hi, first post to the plumbing section
My vaillant turbomax boiler has started making a juddering moaning noise when the hot water is on. It does not do it with the central heating. Sometimes it is constant, sometimes intermittant. If the water is run very slowly (still triggering the boiler), the noise is reduced to just a bubbling type of sound.
Any ideas what the problem may be ?
Thanks,
Simon.

 

[Agile]

I dont remember encountering anything like that on your model.

Usually using a mechanical stethescope would often identify the source of the problem.

The flow regulator would be a suspect although its difficult to reach.

Tony

 

[bengasman]

Which turbomax is it? Photo would help.

 

[simonjay]

I dont remember encountering anything like that on your model.

Usually using a mechanical stethescope would often identify the source of the problem.

The flow regulator would be a suspect although its difficult to reach.

Tony

By flow regulator, do you mean (off the schematic diagram):
Modulating gas valve (I guess not)
Diverter valve
Aqua sensor (DHW flow switch) ?

Simon

 

[simonjay]

Which turbomax is it? Photo would help.

Vaillant turbomax plus 824E
Could get photo later when missus brings camera home.

Simon.

 

[Agile]

I think its within the connectors where the cold water goes into the plate HE at bottom right.

But thats only one possibility. I dont blindly change parts. I try to diagnose the problem first as I described above.

Tony