Noise comming from pipes and from what I have been told on this site my problem is noise bouncing from TRVs which are fitted to all radiators except hall where room stat is. Some of the TRVS were 1 way and were on the return - I have now replaced these with 2 way TRVS. Still getting noise. From what I can gather I need to balance rads. Although some opinion seems to be that with TRVS this should not be necessary. Anyway I have got 2 pipe thermometers which after 30 mins recorded 40C on the flow from boiler and 20c on the return (boiler is new oil condenser model) from what I have learned these thermostats are not very accurate but the important point is the difference. The flow is probably between 70-80. You cannot hold your hand on it. Anyway I am now in the process of checking radiators - I have not touched the lock shields just fully opened the TRVS to get an idea - starting point for the system. The radiators are all reading high 20's into 30's. The difference between flow is between 6 and 9C. From what I have read this should be around 11C. Can anyone advise.