Below you will find step by step instructions for adjusting the expansion valve on the Profitec Pro 500, which is used to adjust pump pressure for the vibratory pump housed in the machine.
- 2.5mm Allen Wrench
- 3mm Allen Wrench
- Flathead Screwdriver
1. Remove the panels of the machine, instructions for panel removal can be found here: Pro 500 Panel Removal.
2. The expansion valve is found at the back of the machine, use a flathead screwdriver to adjust the expansion valve clockwise to increase pump pressure and counterclockwise to decrease pump pressure. Small adjustments are typically all that is needed, no more than a quarter turn at a time to get large results.
To properly adjust the expansion valve, use a backflush blank in your machine to get an accurate reading of where your pump pressure is. Clive recommends setting the pressure at 9.8 bars with a backflush blank to get 9 bars during espresso extraction. It is safe to run the machine with the panels off, you will need to set your water tank in the housing off to the side in order for the machine to run during this test.