Under constant temperature mode, you can manually adjust the temperature of S&A water chiller. 

You can find how to choose constant temp mode here: Selecting Intelligent or Constant Mode on CW-5000 Series Chillers

For example, to set the water temperature at 20℃

1. Press and keep holding ▲and SET buttons
2. Then for 5 seconds and it displays "0"
3. Press ▲ key  to switch to "8" and release the key
4. Press "SET" key, and it displays "F0"
5. Press  "SET" key again
6. Press▼ to adjust to "20"
7. Press "RST" key to save the modification

Here is the chiller manual: S&W CW-5000 Series Chiller User Manual

Here is a video of setting the temperature: