This behavior suggests a leak in the loop valve.

The leak is most likely due to a failed loop valve rotor. It's common that the "Fill" portion of this test will fail, but the "Elute" portion will pass as the loop valve is in a different configuration for the two portions of the test.

Please exchange the loop valve rotor (EV1014) following Section 11.9 "Replacing a valve rotor and or valve stator" in the User Guide.

Degas the system until it is passing specifications. Perform the HP system diagnostic test. Does it pass specification?

Evosep One Diagnostic Tests