I have a Worcester/Bosch 28si combi boiler with 12 radiators. I am getting a high pitched noise from the TRVs. If I turn the valves, either up or down, the noise stops. But shortly after it returns. The one in the lounge is driving my wife batty. Any help would be greatly appreciated

Gerald, November 2007

the noise could be from the velocity of water being to high from the boiler it comes when the valve is closing try putting an automatic bypass valve in

paul h, March 2009