rattling from the bypass radiator

[loon1608]

I have just removed a radiator and some pipe work which involved draining my heating system (combi boiler) Having done this many times without a problem, I was not that lucky this time.
there is a 400x400 radiator in the airing cupboard which is the bypass for the boiler but after filling this time there is a rattle in the radiator (sounds like a piece of metal rattling inside)
I removed the bypass radiator this morning to see if anything was loose but no luck -

ANY IDEAS?

When i removed the radiator and pipe work i terminated with isolating valves as i want to put a new radiator back in a different position -

SHOULD I MAKE THIS A LOOP I.E ATTACH A PIPE TO JOIN THEM?

Many thanks
John

 

[dextrous]

You could try flushing out the radiator in the garden, or it could be the plastic lugs on thw wall brackets that have fallen off/degraded.