Blows

Question

My Kirby is blowing instead of sucking when we try to vacuum. I thought it was only supposed to do this when you take the bag off and use different attachments on it, but it is all put together like normal and we haven't used it to blow anything up for quite a while. It was working fine until recently when it started to blow dirt out. I took it apart this morning and cleaned out all of the dirt that was clogging everywhere from all of the blowing, but it still isn't working properly. I can't find my manual and I can't find a "switch" anywhere to change it. Can you help?