banging in radiator

[micol1873]

hello folks

I have a junior 28i combi boiler (6 weeks old) , I recently replaced all 6 radiators at the weekend as they were old. The all have new danfoss bi directional valves on the new rads and the pipes/system was flushed, cleaned and refilled refilled with inhibitor. I have checked all the setting arrows for the flow on the radiatortrvs and these are set correctly for correct flow direction.

I am getting a banging from one of the downstairs radiators with the trv on it, if i close this radiator off including lockshield valve the baning moves to the radiator with no trvs on it just two lockshield valves. None of the other radiators are doing it.. totallt lost.. any idea's, !!! thx micol

 

[onlyfitidealboilers]

bits of solder may be stuck in the system.

 

[micol1873]

how do you get it out......fitted a drainoff to radiator with the two lockshields as boiler was installed upstairsand driainoff wasnt fitted... system was drained on sunday through this as thought banging might be dirt and was refilled but still banging...thx