Central Heating Radiators

[kloofnek]

I was not sure which catagory to put this under but here goes...when the central heating is off,my radiators sound as if they are empty but people keep telling me that there is still water in them...so why do they sound hollow when I tap them?

[The Builder]

I had to turn around and tap a radiator after reading this question, Kloofers. How can you tell?

Rest assured, the water always stays in them, whether the boiler is on or off.

Kloof, I think you should get out more ;o)

[gingejbee]

Quite agree! If you had a genuinely empty radiator handy (and who doesn't?) I think you would notice a clear difference when tapped.

[Old_Geezer]

I guess the sound travelling through water isn't so different to that where there is a vacuum inside and the sound is just travelling through the metal of the radiator. (Or were you thinking air was getting in and then escaping again ?)

[johnny37]

might sound naive but I would try bleeding them.