I am trying to install my EF2. I have a brand new set of 3" stove pit kit. It won't work. The appliance adapter wont fit onto the exhaust. I looked at the manual and it states that a 3" or 4" pipe can be used. What do I do? Is there an adapter that goes from 4" to 3"? I tried to find one on pf the websites ( venting pipe.com) and can't seem to find one. I can not afford to buy a 4" vent kit. Can someone help me out here. There has to be a decreaser of some sort right? Or am I doing it backwards, should I be looking for a 3" to 4" increaser?