Can anybody give me advice on why my secondary air tubes stopped working. The stove is about five years old. The tubes worked great untill last year. Now im getting a lot of smoke untill the fire is burning real hot. Im wondering if i need to clean the stove better. I usually scoop all the ashes out and brush what ashes are left thru the grates. Does the stove need vacumned? I bought a ash vacumn but it didnt hardly have any suction so i took it back to the store.