My room is heated with a hot water baseboard heating system. As soon as the system was installed, it was making clicking noises. I figured out a way to attach the pipes to the baseboards, and the clicking noise went away temporarily. Just
recently, I accidentally knocked a textbook from my desk right on top of the baseboards, and after that, when the heat came on, they started clicking like mad, all over again. What I have noticed is that the pipes and the metal baseboard covers only make the clicking noise if the covers are attached to the support brackets; if I remove them, the clicking ceases. I believe this is because when the covers are on, they pull the support brackets tightly together, which increases tension between the support brackets and the pipes. When the pipes heat up and begin to expand, they do not have enough room to do so, and it results in a clicking noise. However, I am not positive that this is what is creating the noise. Also, I can hear a trickling noise coming from the pipes, as if there were air in the system, so maybe it needs to be bled? It's extremely annoying because I wake up early in the morning whenever the heat comes on and cannot sleep. What the heck can be done about this?
If the wall is bowed and the heater is tightly secured this could cause these noises. Since you hear water trickling it also means you have air that needs to be bleed from the system. A auto-bleeded can be added to the heater itself to help with this.