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Thermo Fisher Scientific

Pump Problems


How to troubleshoot if the unit is experiencing peak pump problems?


  • Vanquish Flex Binary UHPLC System
  • Vanquish Flex Quaternary UHPLC System


Piston seals in pump leaking Replace the seals (refer to Pump Operating Manual).
Air trapped in pump head Purge the pump (refer to Pump Operating Manual).
Baseline fluctuations See "Periodic baseline fluctions" in Baseline on page 121.
Pump pulsation or flow fluctuations See "Pressure pulsation or inconstant pressure" in Pressure on page 120.
Irreproducible gradient
  • Change the gradient. 
  • Check the solvent line filters for permeability.
  • Replace the filter frits if necessary. (refer to Pump Operating Manual).

For additional troubleshooting help try downloading the Thermo Scientific HPLC Troubleshooting Guide App. The app is an extensive tool to effectively diagnose various potential issues with HPLC analysis.

Thermo Scientific HPLC Troubleshooting Guide App (Apple App Store)

Thermo Scientific HPLC Troubleshooting Guide App (Google Play) 


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