Clean everything often, the full boiler every other weekend, also under the grate.
Smoke moves freely (the full chimney is cleaned every autumn), but when I reduce the blow numbers then even from the chimney on the roof I could see black smoke. Right now there is at least white smoke.
The flame is strong and bold even on 40%, on 100% the flame is really long and reaches even the ash tray.
Yes I understand there is something wrong and that's why I'm here for help
![:) :)](./images/smilies/icon_smile.gif)