I never intentionally stop the roaster between roasts. I believe I was warned not to power off the roaster when it’s still hot as the residual heat can damage wiring with the exhaust fan stopped. [ We need input from @jacob about this ] I always vacuum the chaff collector after a roast session (3-5 roasts of 550g each) and (in the past) at a minimum check the basket after 2 roast sessions. If I don’t see a lot of light thru the filter it gets cleaned. However…
I had an instance where the the filter in the chaff collector became clogged thanks to a lot of fine chaff and what I guess was oily residue (or maybe moisture from the drying phase). The filter basket was so clogged after 2 roasts the exhaust fan was literally pulling the basket out enough to contact the fan. That slowed the fan a lot so that, between the clogged filter and the drag on the fan, the air flow got so low it overheated the roaster. The rubber had become so soft from all the heat (not enough air moving thru the filter) that the filter basket just wouldn’t stay seated and would sag down enough to touch the rim of the fan impeller.
Since that occasion I’ve made it a point to carefully seat the edge of the filter basket inside the inner groove in the EDPM filter basket mount. But seating the filter basket in the groove won’t help if the filter becomes clogged with debris. If you’re mid-roast, there’s not much choice but to dump the chaff and clean the filter basket so you can get air moving again and cool the roaster properly.
Since the problem above I have started pulling the filter basket after every session to be sure it isn’t clogged with fine particles. This is contrary to the general maintenance guidelines Sweet Maria’s presented in their video back in Jan or Feb.
Btw, I had gotten the over-temp ErC so there was no continuing the roast at that point. I’ve never tried roasting those beans again!
I can’t recall: have you calibrated your exhaust fan recently? I wonder if the calibration data has somehow become corrupted and the fan isn’t running as fast as it should. Only takes a few minutes in Off mode so it doesn’t require heating the roaster.