Boosting Pressure -3 PSI - Spectra Connect

Boosting Pressure -3 PSI.

When you start a run cycle, the first thing that happens is a small centrifugal boost pump turns on and builds pressure at the inlet of the larger feed pump. Here, the “boost pressure sensor” is looking for 15 PSIA (this is 1 PSI above a vacuum as we do not want the vane pump operating in a vacuum & drawing its own water). Once the 15 PSIA is reached (the “boost pressure setpoint”) the system starts. If you see a screen that says “Boosting Pressure : -3psi” it means this pressure sensor has a bad connection or is faulty. This pressure sensor is marked with a yellow band and is connected to the three pins labeled 5V, PRES1, GND.

         Connect Circuit Board                        Catalina Pressure Sensor & Board   Newport Pressure Sensor & Board     







The most common cause for this issue is a loose, intermittent, or unseated connection at the absolute pressure sensor.

  • The first thing you should do is unclip the pressure sensor cable, clean/grease the connection, and clip it back in. If this does not get the sensor reading correctly, disconnect green plug on the circuit board, wipe a small amount of grease on the bottom of the connector and plug it back in, make sure you hear a good snap as it clicks in.

If both ends of the cable are securely connected the pressure sensor likely needs to be replaced. The part number and description for the transducer & cable is:



Bypassing this pressure sensor will allow you to run the watermaker. However, doing this will disable two critical parts of your system. This will disable your system’s ability to monitor filter condition. Disabling this will also disable the boost pressure set point. If boost pump fails, the vane pump will draw in its own water in leading to wear at a significantly faster rate. Vane pumps without a boost pump can fail in one year. Change your prefilters frequently and check the operation of your boost pump regularly (Boost Pump Test)

To bypass this sensor the user must navigate to the Boost Pressure Setup Screen: 

Tap the menu bars, then Dealer Access Point (password and username are both “admin”), then General Settings, then Boost Pressure Setup. Once in the Boost Pressure Setup screen, click the dot under enable next to the PSIA sensor so that no bubbles are filled in. Finally tap back, back, back and save.