'Ticking' radiators

[marctwo]

When my heating is on some of the radiators in the house make a ticking sound. I found that turning down the thermostatic valve from max stops this. Does anyone know what it is? One rad is old but the other is new.

[mxspyder]

I always assumed it was the metal expanding and contracting, never really thought about it though. I will be interested to see what one of the knowlegable people on here come up with!

[cod man]

Might be air bubbles going through?

[marctwo]

cod man said:

Might be air bubbles going through?

That's what I thought it might be but it only happens on some rads, not all. Is this something to worry about?

[s1962a]

It's the metal cooling and 'rubbing' against the brackets that hold it to the wall. A lot of the newer ones come with plastic spacers which you put over the bracket hook so the radiator has a bit of play against the bracket and hence doesn't tick.

[marctwo]

s1962a said:

It's the metal cooling and 'rubbing' against the brackets that hold it to the wall. A lot of the newer ones come with plastic spacers which you put over the bracket hook so the radiator has a bit of play against the bracket and hence doesn't tick.

'Ticking' is maybe not the best description. They 'tick' when heating and cooling but this is more of a fast tapping sound that is constant when the boiler is on. Air bubbles seems the most likely explanation but it only affects 2 rads in the house.

[Gingerbread Man]

marctwo said:

s1962a said:

It's the metal cooling and 'rubbing' against the brackets that hold it to the wall. A lot of the newer ones come with plastic spacers which you put over the bracket hook so the radiator has a bit of play against the bracket and hence doesn't tick.

'Ticking' is maybe not the best description. They 'tick' when heating and cooling but this is more of a fast tapping sound that is constant when the boiler is on. Air bubbles seems the most likely explanation but it only affects 2 rads in the house.

Air normally collects in a select few rads and not in others due to pipe runs. Towel rails normally collect air.