Below you will find the step by step process on draining the boilers of the Profitec Pro 300.
Things needed: ~20 oz cup
1. Machine will need to be on and both boilers need to be fully heated.
2. You will drain the coffee boiler first. To do so, turn on the grouphead so water starts to flow, remove the water tank while the grouphead is running and it will continue to flow for a few seconds. When the water stops flowing from the grouphead (roughly 2-4 oz after removing the water tank), turn the machine completely off.
2. Once the machine is off, open up the hot water valve and the pressure of the steam boiler will push all of the water out of the steam boiler (about 20 oz of water will come out).