DIY Doctor UK DIY Forums

Our C/Heating system is driven by a Worcester/Bosch Highflow 4.5 combi.
We are experiencing loud vibration noise like a pneumatic drill in the pipes which is cured by slightly altering the thermostat on one of the downstairs radiators. This can happen several times in an evening when its on.

I have bled the radiators today and there was a lot of air in the system; I did allow more water into the c/h system several times by opening the valve at the boiler before bleeding the next radiator. The noise still occurs. Is there anything else I can do or should I call in a Pro? Thanks

Peter

If the noise stops when you alter just one TRV the valve is either goosed, or fited on the wrong pipe making the water flow the wrong way through the valve. There should be an arrow on it indicating the direction of the water flow. You can find the flow direction through your rad when you first turn it on as the flow is from the hot pipe to the cold pipe, turn it on and see what one heats up first.