CH Noise

[BillW]

Hello all. Hope someone can help.
Just changed boiler from standard Gloworm to Worcester Bosch 37CDi condensing combi by accredited Worcester engineer. System flushed, kept same rads but he changed all the lockshields and TRVs. All seems ok except when the heating starts I can hear what I can only describe as a low level, irregular and persistent drumming/droning/vibration around the main bedroom and en-suite. With ear to the en-suite rad I can hear what seems to be the same noise, slightly clearer at the top and bottom and a slight vibration. Don't seem to get this from any of the other rads.Bled all the rads but noise still there. Engineer visited but frustratingly said he couldn't hear anything untoward but turned down the boiler pump anyway which made no difference at all. Noise resonance can occasionally be heard above other ambient sounds and is very irritating. Help!!
Cheers
BillW

 

[wards]

was the system cleaned and flushed?strange it is only on this one radiator.

 

[Billy Bob Bob]

faulty trv or rad valve restricted to much what your hearing is numatic noise

 

[BillW]

Thanks.
Wards: Yes the engineer flushed the system (not power flush, the house is only ten years old). Inhibitor added and a Magnaclean filter built in.

Gas man: So do you think one or both valves are faulty and need replacing? (BTW I did fully open the TRV and opened the lockshield a little more:made no difference). For info as well, the TRV he's put on is a Danfoss bidirectional on the return side. I checked the TRV flow selector - it was facing the correct way: changing it to the other way made no difference either.
Ta
BillW

 

[LIFES A GAS]

Turn off the radiator in question, is the noise still there? if it is then its not the radiator or valves on that one, you could do the same thing to other rads and see if the noise stops.
Martin

 

[BillW]

Thanks Lifes A Gas.
Did as you suggested - turned off all rads one at a time by closing each TRV fully. Waited a minute and when the sound persisted reopened the TRV to its previous position then did the same to the next rad and so on until all 12 rads were done individually. Sound still there as before ie more noticable in main bedroom and en-suite but resonance detectable elsewhere.
As it happens had engineer out again today - he still claims - unbelievably - that he can't hear it but suggested that any sound may be due to the original piping system reacting to the new higher pressure?
Ta
BillW

 

[oldplumber]

could be some pipes arent secured properly and are vibrating a bit, try tracing back the noise to its source and see if its the pipes, more likely to be a lockshield closed down to much or a faulty trv as stated previously

 

[BillW]

Thanks Old Plumber.
Tracing the noise to its source is proving difficult. The en-suite rad appeared to be the source but I've changed it and the noise persists so I'll be looking at the new piping and valves soon.
Ta
BillW

 

[Plouasne]

You could also try replacing your ordinary pipe clips, with sound deadening pipe clips like these, collier isophonique, I think that you should be able to get something like these in the UK

FTI - Colliers - Fixation sanitaire

5 colliers isophoniques Ø 14 - CASTORAMA

 

[BillW]

Cheers Plouasne Ill look into that.
BillW