Hello all

I hope someone can help me with this problem as it is starting to really
annoy us.

I leave the heating turned on at the timer in the airing cupboard and
control the heating with the thermostat situated in the hall.

After the heating has been on for a few hours (this is not constant) at
approximately 20 Degrees C there is a very loud banging that sounds as if it
is coming from the airing cupboard.

There is also a kind of crunching sound that comes from the radiators even
though they are warm.

If I run the hot water tap for a few seconds then the banging will stop.

I have tried to bleed the radiators using the key but there is little or no
air in them.

Is there anyway to get rid of air in the system easily without having to get
a plumber in?

I had thought about draining down the system but do not really know how to
do this and also do not know if this would get rid of the air.

Thanks in advance for any help you can provide.

Kevin