I have recently had a Jotul 400 stove installed by a HETAS installer and have the certificate to prove it! The chimney is lined with pumice and there are approved air vents in the room. The stove is advertised as having an airwash system but the door glass keeps sooting up and I cannot keep the stove in overnight even when it's loaded with wood and the air control on the stove is turned to minimum. The logs I'm burning are quite small so I guess larger logs would be more dense and may take longer to burn but the stove does seem to burn logs very quickly. I had a woodburner in a previous house and had no similar problems so I begin to wonder if there is a problem with too much draught but if that were the case then I wouldn't expect the door to soot up? Grateful for any advice.