If the black condensate line that runs from the VistaCool system to the drain adapter assembly appears to be blocked, the inline thermal sensor has been activated, blocking condensate flow to the drain.
It's likely that the inline thermal sensor has been activated due to a lack of coolant water in the tank that overheated the condensate. By design, overheated condensate causes the wax motor in the inline sensor to expand, closing the outlet to protect the drain.
To reset the inline sensor and enable flow to resume, allow the system to rest and cool naturally. The inline sensor’s wax-motor piston will retract, opening the outlet port.