humming noise in pipes

[Geoffhowes]

I have an unvented heating system which is only 1 year old. When it was fitted they was allot of humming coming from the pipes. I called the plumber back and he fitted an inline valve which seemed to cure it. It has now returned and I cant locate the plumber. It happends on all the taps at different time of the day and even if I turn the tap off slowly it doesn't seem to stop it . Any ideas.
Cheers

 

[kevplumb]

see this

 

[Geoffhowes]

Its a megaflow gas boiler
Im getting humming from the pipes when I turn of the taps
It hapened when it was first fitted and the plumber fitted an inline valve of some sort and it stopped for 10months now it has started again
It started again a few days ago
It hapeds when you shut the tap even when done slowly
Hope this helps

 

[kevplumb]

Its a megaflow gas boiler

new one never heard of it

 

[ChrisR]

FIrst thing I'd look at is your float operated valves (aka ballvalves) in loos and loft cisterns if you have any.
It's quite common that they hum when they're nearly full, solution is to change the washer, which will last a few years, or the whole valve for a metal one , which will probably last longer.
If you press the float down so water comes in and the valve is pushed off hard, the noise will stop - until next time!

 

[Geoffhowes]

The cylinder is made by megaflow, the boiler is glow worm

 

[kevplumb]

possibly the perssure reducing valve