Whistling radiators

[jt racing]

Hi all.
My wife, (honestly my wife did it!), bleed the radiators 4 weeks ago, and since then it's like the upstairs ones are whistling. Not loud, but enought to hear it and it's starting to drive me mental!
I've rebleed them, but to no avail! Any ideas what's going on?
Thanks.

[Big Al.]

Are they fitted with thermostats? if so try tweaking the temp up or down on the stat.

Works for me.

[mrsxllifts]

Get a bit of power behind the water when you bleed them, power flush kind of thing. Connect filling loop and fill to 2 bar, open top vent and leave open til pressure drops til 0.5/0.75 bar, the re-pressurise to correct pressure. Worked for us when we had same trouble, had air stuck and couldn't budge it. Just in case of flaming, I am not a plumbery person this is just personal experience.

[wooly350i]

Big Al. said:

Are they fitted with thermostats? if so try tweaking the temp up or down on the stat.

Works for me.

Also the balancing valve on other end may be shut down too much causing restricted flow and noise. John

[Gingerbread Man]

Is the lockshield valve cranked right down causing the whistling noise as the water forces its way through the valve?

Try opening it a turn and see If it improves. Don't turn it too much though as you could upset the balancing of the system, so remember what you do.

[jt racing]

Thanks everyone. Was going to have a crack at them last night, but then they stopped!!
Ha, they must read pistonheads too!