My boiler is making a ticking sound, any idea what it might be?

My boiler is making a ticking sound, any idea what it might be?
I have a Ferroli F24 CH boiler and recently it has started making a ticking sound. The boiler sometimes switches into backup mode, a red light comes on and it needs to be reset, but otherwise it works fine. Even after backup mode has been reset the boiler continues to work fine. The ticking sound is different each time, sometimes its a single tick/click then a short break and sometimes it can be continuous. Does anyone have any ideas?


Answers:

paul:  some one has planted a time bomb in it tic toc tic toc
2010-04-06 23:59:17
b:  expansion and contraction ue to heat
2010-04-06 23:59:53
The Plumber:  Read the instructions and trouble guide at the link below or just call the manufacturer.
2010-04-07 04:23:15