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ACQUITY Solvent Manager Error: Degasser vacuum h/w failure (1) - WKB20487

Article number: 20487


  • "Degasser vacuum h/w failure (1)" error in console upon ACQUITY Solvent Manager power-on initialization
    • Degasser error code 1 indicates that it took more than three minutes for the vacuum pressure to fall below 0.909 psi
  • Fault occurs when turning the system back on after the instrument had been shut down
    • Upon initialization, the degasser pump is unable draw down to effective vacuum pressure at the sensor


  • ACQUITY UPLC Binary Solvent Manager (BSM)
  • ACQUITY H-Class Quaternary Solvent Manager (QSM)
  • ACQUITY I-Class Binary Solvent Manager
  • ACQUITY Systems Driver Pack 4 SR1
  • ACQUITY Systems Driver Pack 2017 Release 1


ACQUITY solvent managers pull down a vacuum for only three minutes upon initialization. This amount of time is insufficient.  Three minutes of draw-down does not effectively purge solvent vapor from the degasser tubing for all mobile phases.

  • Teflon AF tubing within the degasser chamber bleeds during periods of downtime.
  • Common solvents such as acetonitrile and methanol condense over time as vapor escapes the Teflon AF tubing within the degasser chambers
  • Solvent vapor pressure rises, making it difficult to avoid degasser faults when turning on the instrument after an overnight or weekend idle period.



Recycle instrument power to restart the three-minute pump-down cycle on the degasser.

  • It may take several cycles to purge the vacuum lines of excess solvent vapors.
  • This will effectively purge degasser lines of excess solvent vapors and pull down to suitable vacuum.




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