noisy radiator

[baza72]

one of my radiators makes a banging noise and the water going through it sounds like being at the beach.this only happens first thing in the morning when heating comes on,rest of time no noises.boiler is 6 years old,radiators are older.no other noises or problems anywhere else.system recently serviced and all radiators were bled.idiot guide required nothing to technical.

[Bryan King]

is it a thermostatic valve on the radiator, if so it may not be bi flow and could be on the wrong way round. Their should be an arrow on the valve stating direction of flow.