lots of smoke

[stone]

i have a buderus 02.40 wood/coal add on boiler, for 2 weeks it worked great a lil smoke(which i figured was due to a missing smoke screen) but all i did was open the door a crack and the smoke cleared then i could manage the fire. the other night i tried to add more coal and it was smokeing alot, unbareabe, so i figured it might of been a lil too much coal and not enough red coals, that i may be smothering it, so i opened the bottom door to try and burn it up and give it a cleaning, when i went to clean it there was alot of really thick black dust almost like tar all around the top heating grates so i thought that this might of been the problem that it was blocking the smoke from exiting, so i cleaned it good but today the same thing is happeneing when i open the loading door the smoke it unbareable to stand to load more coal, i can light the fire great, and burns well, with no smoke, but one i add coal to it after about 20 minutes of burning it starts to smoke, im only putting on 2 small shovels of coal at first, so i done think its an over loading problem, im thinking a draft issue, but it worked so well for 2 weeks that it has me puzzled. is there any suggestions or should i just call in a tech? thanks alot

 

[derbygreg]

http://www.nepadigital.com/bb/index.php

You will likely get a better response on the Anthracite Coal Forum