5.0 How to Maintain Solinst Pump Controller

Moisture in the Model 464 Electronic Pump Control Unit can shorten the lifetime of some of its components. After each sampling session, compressed air or nitrogen should be sent through the Pump Control Unit to ensure that any build-up of moisture is purged and pushed out of the Pump Control Unit, as well as through the Supply and Drive Lines.

Connect the compressed air/nitrogen gas source and let it cycle through the Pump Control Unit with the drive line disconnected at the pneumatic pump. Set a 10 second "Drive Time" and 2 second "Vent Time". This will create a pulse of air to purge the system components. Maintain this purging cycle for 10 minutes.

If you are using the 464 External Filter, use the draining valve as necessary to prevent water from entering the 464 Electronic Pump Control Unit.


If moisture is observed exiting the diffuser on the Drive Line exhaust fitting when the pump is venting, remove the pump from the well and check for damage (o-rings, bladder, lines).

Of note, sources of moisture may include:

  1. The air compressor - follow the manufacture's suggestions for routine maintenance for draining the air tank from a build-up of moisture.
  2. Sample backflow - best practice is to maintain the Control Unit at a higher elevation than the Drive Line connection at the wellhead. This height difference reduces the potential for backflow into the Control Unit.
  3. Precipitation
    • avoid direct exposure to precipitation or water splashing;
    • ensure that your Control Unit is stored dry, inside and out.
  4. Pump damage − leaks in tubing, a ruptured bladder, or damaged o-rings can cause backflow. Regularly monitor pump condition and replace parts as required.