When pressure reading on the controller gives unexpected results, check the pressure sensors by calibrating them see Calibrating the pressure sensors.
When the controller display shows a sensor error, and you are sure that during the calibration there was no pressure, flow or vibration, then the pressure sensors must be exchanged.

Before you start:
● Make sure you have threadlocker available that is suitable for drinking water (for example LOCTITE 243). Threadlocker is used to lock the pressure sensor to the valve block.
● You will need a 22 mm torque wrench (for 10 Nm).
● Make sure that the O-ring flat seal is present on the new pressure sensor (see figure).

To exchange a pressure sensor:
1. Remove the controller from the valve block as described in Removing the controller from the valve block.
2. Remove the cable from the existing pressure sensor. If both pressure sensors are replaced, mark the cables to make sure that you connect them to the correct sensor after replacing.
3. Remove the pressure sensor using a 22 mm wrench.



4. Apply a tiny drop of threadlocker on the beginning of the thread of the new sensor.
5. Carefully insert the new pressure sensor into the valve block and turn it in by hand.
6. Tighten the sensor with the 22 mm torque wrench with 10 Nm.
7. Connect the cable to the pressure sensor.
8. Put the controller back on the valve block and attach its four screws.
9. Calibrate the new pressure sensor as described in Calibrating the pressure sensors.