Fan preview
- Chris Hilder
This feature starts the fan without any heat being applied so that you can verify that the beans are circulating properly in the roast chamber for the upcoming roast. It is available from the ≡ button.
A correctly calibrated fan normally means correct fan speed is automatic, but variations in bean density and batch size can sometimes cause problems with correct circulation. Fan preview lets you verify that there is not a problem, or make adjustments if there is.
During fan preview you want to see the entire surface of the bean mass moving. Pay particular attention to the beans in the centre. If you need more circulation, either reduce the load size by removing some beans from the roaster, or increase the fan speed by increasing the BOOST load size setting. Aim to use the lowest fan speed possible that gets the entire surface of the bean mass moving.
If you are seeing consistently low circulation with correct load weights this may be an indication of the need for recalibration, see Bean circulation calibration.
Note
Fan preview requires firmware version 7.10 or higher. If you need to update, see Update firmware.