I have a maybe 20 year old Morso 1600. I bought it secondhand some months ago. When the fire is well burning with some Jarrah logs (I'm in Western Australia and this is the best wood), I open the door and smoke comes out. Is this normal? It drives me nuts. I had a Jotul 3 before and never had this problem. I've attached three photos. the inside bits all look okay. it has bricks inside too. do i need new bricks or something? The flu has soot in it as I burnt some painted jarrah from a pergola. Any advice please?