Service Prefilter - MPC (systems with NO boost pump)
*Systems with no boost pump include Ventura product line & MKI Catalina/Newport systems*
The Service Prefilter alarm is triggered by pressure sensors on either side of your filter bowls. The alarm is designed to trip when the filters get clogged and the difference in pressure between the two sensors hits a programmed limit, the Differential Limit.
DIFFERENTIAL LIMIT: This function compares the pressure reading from the two pressure sensors (red and green) on the 20 and 5 micron filter housings to determine the pressure drop across the filters. The left hand number on the display is the real time pressure differential and the right hand number is the maximum differential set point. If the pressure drop across the pre-filters exceeds the set point the system will alarm “Service Prefilters” and shutdown. Factory default is 10 PSI.
If you want to use the differential limit to help bypass the alarm, you would want to increase it from 10. However, doing this or messing with the offset is really just masking the issue. The differential limit doesn’t go too high for safety reasons, it’s meant to go lower for people who want no chance of dirty filters.
INLET OFFSET: This parameter calibrates the pressure sensor on the inlet side of the black prefilter housings. This sensor, and its cable, are usually marked with red heat shrink tubing. The number on the left is the real time pressure reading and the number on the right is the offset. Factory default for this is 0. The reading can be increased or decreased by putting a positive or negative number in the offset setting.
OUTLET OFFSET: Outlet offset calibrates the sensor on the outlet side of the black pre-filter housings. This sensor, and its cable, are usually marked with green heat shrink tubing. In addition to providing the differential pressure reading, across the pre-filters, this sensor also provides the Feed Pressure reading. The number on the left is the real time pressure reading and the number on the right is the offset. Factory default for this is 0.
If you think you are having a sensor issue, you should start running the system with the "Run Manual" toggle switch. Then, with the system running, enter the programming settings and note how the real time value is behaving.
Our linked YouTube video goes over how to access the MPC programming. https://www.youtube.com/watch?v=RCRWLuhTB10
Print instructions are also available at https://katadyngroup.ladesk.com/961525-Programming-From-the-Display-Definitions--How-to-Access
If the numbers jump around more than 10 psi you will need a new sensor. If the numbers seem steady but unreasonable, we suggest you take them off and clean out the port with a wire or paper clip. If cleaning doesn't do the trick, you may need to disable the alarm and get a new sensor. You can also open the pressure relief valve and check that both the pressures drop, or at least change. Upon opening the pressure relief valve, if one drops and other does not then you know that sensor that did not change is not working properly.
See Pressure Sensor Test for tips on testing our pressure transducers.
------------- If you are seeing Service Prefilter when you freshwater flush your system, see this link for help -----------------