Gas and Oil Home Heating Furnaces - heating vents

I just moved into a new home and some of the heating vents blow out more air then others. I tried to move the slide on the registers to see if more heat would come out but it did not work. I have electric heat in the house. Is there any way to go into the vents and see if something is blocking the vents and perhaps adjust air flow that comes through them? any help would be appreciated, thank you in advance. Margie

they will be evident from outside the duct by a handle sticking out. these are generally located at the "takeoff" or where the individual duct run comes off the trunk. if none are present, you may want to add some in the ducts that you are trying to divert air from. these are merely round sheetmetal discs inserted in the duct with a handle to adjust volume. when the handle runs parralell to the duct, it is open, when perpindicular, it is closed.