Since we started using the central heating again a couple of weeks
ago, when
the heating is on I can hear a dripping noise when sat in the lounge. The
noise appears to be coming from the ceiling, probably where central heating
pipes run. So far there is no water mark on the ceiling and I can't feel
anything damp but the dripping noise can be quite rapid at times and then
slow down for a while.

Is it likely to be a leak or could it just be expansion?


Most likely to be expansion as others have explained.

Once pulled the place apart for a moth fluttering behind a large mirror.

The problem was that I was worried that loft tank was overflowing -
won't go into complicated reasons why I thought this might be the case
but the important lesson is that your brain interprets what you think
you fear as what you are hearing - the fact that there was no water and
the noise was intermittent did not figure as I KNEW what is was.

Of course a moth fluttering its last does not sound like an overflow and
now if I hear that noise my brain tells me it is a moth so I will miss
the overflow if it happens.

http://www.diynot.com/pages/pl/pl034.php#a1

No matter how careful the installer is, creaks seem likely at some time.
My best successes seems to have been with the saddle type of clips with
a plastic saddle that you push the pipe into. In your case you might
decide to live with it or when you can get access try something - start
with slackening off a little repeat little any screws holding metal pipe
clips. Don't fasten back the floor boards until you are sure you have
got it fixed as you are very likely to want to go back to it.

Most creaks seem to occur where there is a right angle bend and/or
restricted space.


Here in an old cottage I am pleased the mice no longer squeal with the
heat as the pipes warm up.


--
PK
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