What is it if it isn't air in rads?

Dec 17, 2003 7 Replies

Sat here - the rad to my right keeps gurgling and making noises that I assume is air passing round in it. Yet it's red hot - and when bled - there's nowt in it. Any air in the system collects in the top of the tallest rad - and that is the subject of my post earlier this week.



So what the hell is it if it's not air? It's making that gurgling noise like it should be air - now I'm flummoxed.



Cheers Dan.


if it's red hot then maybe you've got steam! if the boiler temperature is too high and producing steam in the system them you would get "steam hammer" in the system making those noises. Can you slightly reduce the boiler water output temp?

The Q

Q, it's not that hot - but uniformly hot with no cold spots or dead spots. Very odd.

I can turn the stat down a spot and see if it makes a difference -it's not even on half now tho! And it's only a small boiler :)

Cheers Dan.

It probably is air, Dan.

The only other option would be hydrogen, but it would not be being produced at the rate that you are experiencing

.andy

To email, substitute .nospam with .gl

Probably is air, drawn in down the vent pipe by the pump being set to high. Or if you have circulation through the header tank simply coming out of solution when the water is heated.

Air will generally collect in the first rad from the boiler, this may or may not be highest one.

It doesn't always collect at the highest point - life's not that simple. If you're not using inhibitor (Fernox) that's worth a try - for some reason it seems to quieten down this sort of noise. However, if you've just re-filled the system it should eventually go away if it's not sealed.

It must be air - grrrrr - more things to try and fix :)

Cheers Dan.

Hi,

Is production of steam a bad thing? How bad?

Steam came out of my rads when I bled them the other day.

Dave

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