My fuel oil furnace has smoke bellowing out of a cracked between the fire tube and the crock. Can it be repair

Should there be a gap between the fire tube and fire crock? It also does'nt want to fire if it's shut off or tempiture is turned down for a while. I have to hit the reset button in order to fire it up, that's when the smoke comes out of the inspection plate and exaust pipe. Should and can I get some stove cement and close the gap between the fire tube and crock?My fuel oil furnace has smoke bellowing out of a cracked between the fire tube and the crock. Can it be repair
well either do that or call a furnace man right away thats carbon monoxide coming out...with the smoke..My fuel oil furnace has smoke bellowing out of a cracked between the fire tube and the crock. Can it be repair
get a cleaning and have the person tell you what else you need done. some will tell you if they think you can handle it yourself.
yes but i suggest calling a professional