Why does it growl

The “Low Growl”

The low growl means the motor is working hard, and the cooling fan is not at full capacity.

The low growl happens when the air pocket is popped by the shove of the tamper, and the blades “grip” a thick concoction. That is when the motor is really working hard (and heating up). There is nothing wrong with the low growl as long as it doesn’t continue for too long without any breaks. The low growl is when the blending is happening.

You want the blending to happen, but it is good to create a balance between the low growl, and the high pitched whine. For many recipes this happens naturally, because every time you shove the tamper into the mix you get the low growl for a few seconds, then when you pull the tamper up you get the high pitched whine. Nut butters and ice creams are like this. In the beginning there is a lot of tamping before the mixture gets blended enough that it will flow freely through the blades on its own. Each shove of the tamper should cause a low growl (a little bit of blending) followed by a high pitched whine (an air pocket), and this happens over, and over, and over. This creates a natural balance between heating and cooling.

If you are making something thick, using the tamper a lot, are tamping quickly, and are doing this for a long time, the motor might not get a chance to cool off. Sometimes you will get a burning smell coming off of the motor when it is over heating.

If the thermal heat sensor trips the Automatic Overload Protection, and your machine turns off, unplug it, and let it sit for 45 minutes to cool off. Once it has sufficiently cooled, it will come on again. Or, if you are like me (impatient) you can use a hair dryer (on the cool setting) to cool off the motor. Blow the cool air into the air vent. The air vent is on the back of the next generation machines, and on the bottom of the standard models.