I see that the CW-3000 units on ebay are sold either as 220V or 110V units. Is the difference the setting of a switch on a power supply, or is it a completely different AC pump motor, or is it how an AC pump motor has been wired?
I’m wondering; if I get a 220V unit because I plan to use it right now for a water-cooled spindle, if I later have a reason to want a 110V unit am I just flipping a switch, changing pump motor wiring, or buying a new unit?
On my unit the voltage is fixed. The fan is AC powered with only two input terminals and the pump is powered by a 110V input DC power supply. There is no way to change them to 220V.
Mine is fixed at 110V as well.
The 220V CW-3000 I purchased came with a 110V plug 
, but otherwise appears intact, and I plan to wire it into 240V router spindle system anyway. One missing nylon washer, and one ding in the radiator fins, but nothing otherwise obviously wrong from inspection.
The 24V DC adapter is 110-240V input, but at least the fan and the water temperature sensors are specifically 220/240V parts. I didn’t pull apart the wiring loom to determine whether the pump is 24VDC or 240V.
I love that “FORBIDDEN TO ANHYDROUS BOOT”
I’ll wait to test it until I purchase sufficient distilled water.