Had a customer call me today to thank for for my advise I gave him last week. He called stating his stove we installed a few years ago wont draft this season and was asking about the outside air kit. Always getting smoke back in the house. I found out he did not have the chimney cleaned or inspected since before last season. I said the cap was probably clogged up, classic symptoms. I ran through all other things he could check since he did not want to climb on the roof in the ice / snow. Well when I talked to him today he did end up on the roof and found an 80% plugged cap. Works like new now that he cleaned it out.