ProMinent Duodos 20 PPS Assembly And Operating Instructions Manual page 22

Troubleshooting and fault elimination
Air bubbles in the feed chemical.
Cause:
The diaphragm is faulty.
The suction hose is loose or broken.
Leaks or air pressure fluctuating between 3 ... 8 bar.
Cause:
The directional valve is closed or faulty.
Pump does not start. No regulated air pressure.
Cause:
Immovable air pressure sensor.
Close directional valve.
22
Recommended measure:
Remove and check the pump and replace the dia‐
phragm.
Fasten or replace the suction hose.
Recommended measure:
Replace the components of the directional valve.
Recommended measure:
Replace the air pressure sensor.
Replace the components of the directional valve.