u/swegpeg

I just bought a 6 months old second hand Behmor 2020SR and tried to roast it today. I put in 250 gr of green beans, pressed the 400g/1lbs setting and P1. About 3 or 4 minutes into the roast a lot of smoke stsrted coming from the exhaust on the backside of the roaster.
I’ve now tried it without green beans and the same thing happens.
The unterior seems pretty clean, not a lot of built up chaff there. What could be the cause of this and how should i go about solving it?