Boiler/pipe wining ringing noise

[AnnaD2002]

I really hope someone can enlighten me here! Our boiler (Main Eco Combi, installed less than a year ago before we moved in) has been making a really loud ringing noise when the heating is on. Stops momentarily when we run the hot tap at either of the taps in the house. I have had a plumber round twice to check it out but both times it has been silent (sods law). He says the boiler looks in good nick and well installed.

I think I have isolated a pipe where the noise is emanating from. I took a floorboard out from one of the upstairs bedrooms and tapped on the pipes under it - one of them seems to be the culprit as when i hammer it the noise changes or stops altogther. See video. What is the problem?!

http://www.youtube.com/watch?v=005hNFdNj-M&feature=youtu.be

 

[Gas2Air]

Nice hammer work! It's obviously vibrating on a joist, poorly notched somewhere!

 

[AnnaD2002]

I don't think it is vibrating on a joist. We have taken more floorboards up and wrapped towels round the pipe on the joists to dampen the sound and it didn't stop. It sounds like it's coming from within the pipe. The noise transmits all the way down to the boiler. It's driving us insane.

 

[Joe4542]

When it's doing it, try closing the CH flow isolation valve, black tap furthest to left side when looking under boiler. If it stops, it could suggest an issue with water flow.

Not noted as a problem on the main eco's, but others had a 'singing' noise like yours caused by faulty/damaged o-ring in diverter cartridge, allowing water to 'squeeze' past causing that noise.

 

[AnnaD2002]

Thank you Joe! Noise started again so we turned that valve and it stopped the noise. Turned it back again. Just waiting to hear if noise starts again.

 

[Joe4542]

Sometimes closing and opening the flow (as you've done) will cause it to clear the debris from the diverter valve seats, but sometimes the seals/divvy will need changing.

 

[chantelle]

It's obviously vibrating on a joist, poorly notched somewhere

Another gas bloke who has never done any plumbing in his life.

 

[Dan Robinson]

And your suggestion to the OP is?

 

[AnnaD2002]

So our plumber has told us to close the valve on the return pipe slowly to see if reducing the flow will make a difference. Hope it does!!

 

[chantelle]

Probably a tap head/ washer on hot water side, lever tap is notorious. These are ceramic cartridges, for any gas muppet out there.