There could be two reasons why your forced baseboard heat could be making noise. The first reason why your baseboard heat could be making a rolling noise is because you need to bleed the air from the pipes. The second reason could be that you are experiencing something called water hammer and that’s a completely different noise then the rolling noise that you will get from air in your heating pipes.

Water hammer is caused when cold water and warm water collide with each other inside of the heat loop. The heat loop is the run of pipe that connects from the boiler to the baseboard heat and then loops back to the boiler again. When cold water is laying inside of the heat loop and then the boiler forces hot water into the loop that’s when the “water hammer” can happen. Most forced baseboard heat elements like Slant Fin will have plastic clips on the bottom of the element to help prevent the baseboard from banging so loud if water hammer was to happen.

If your boiler has been off for several months and you are hearing a rolling noise inside of your heat loops when you turn your heat on then you could have some air in your pipes. When air is trapped inside of the heat loops there is space for the hot water coming from the boiler to roll or twist the water around inside of the heat loops and the baseboard heating elements creating a noise. This rolling noise can be fixed by bleeding the air from the heating zone.

Its always a good idea to have your forced hot water boiler serviced before you start it up again for the winter. Over the summer or the off season water can evaporate or be lost and then when you start the heating season you could have water hammer or water rolling through the pipes creating noise inside of the heating elements.

Another thing you will also want to check for is to make sure that you have all of the plastic clips in the correct spot underneath the heating elements. On Slant Fin baseboard heat which is the most common type of forced hot water baseboard heat you will find gray clips that fit between the aluminum elements and the brackets. If these clips come undone or are possibly in the wrong spot your baseboard heat could also make noise. You will want to make sure that the gray clips are securely mounted to the bottom of the heating element and are laying correctly on the bracket. If your clips on the bottom of your Slant Fin heating are in place and you still have noise when your boiler calls for heat then you will want to check to make sure all the air has been bleed from the heat loop zone. This can be done by a professional plumbing and heating company.