| Problem | Cause | Solution |
| Pump is running but does not reach the pre-set pressure | Pump is sucking in air | Check inlet ducts and make sure they are air-tight |
| Valves are worn | Check and replace |
| Regulating valve seats worn | Check and replace |
| Nozzle inadequate or worn | Check and replace |
| Seals worn | Check and replace |
| Pump not sucking | Pump is sucking in air | Check inlet ducts and make sure they are air-tight |
| Suction level too low | Check inlet water level |
| Inlet valves dirty | Disassemble and clean the inlet valves or connect the pump inlet to the water mains and pump for a few minutes |
| Irregular pressure oscillation | Inlet and/or outlet valves worn | Check and replace |
| Foreign matter present in the valves jeopardizing their functioning | Check and clean valves |
| Pump is sucking in air | Check inlet ducts and make sure they are air-tight |
| Water seals worn | Check and/or replace seals |
| Drop in pressure | Nozzle worn | Change nozzle |
| Inlet and/or outlet valves worn | Check and/or replace valvesCheck and clean valves |
| Foreign matter present in the valves jeopardizing their functioning | Check and/or replace the regulating valve seat |
| Regulating valve seat worn | Replace |
| Water seals worn | Replace seals |
| In case of belt drive, belts are slack or worn | Replace belts or adjust tension |
| Excessive noise | Pump not being fed correctly | Check that the suction level is not too low or that the suction pipes are not blocked (e.g., filter clogged) |
| Pump is sucking in air | Check inlet ducts and make sure they are air-tight |
| Inlet and/or outlet valve springs damaged or broken | Replace valve springs |
| Foreign matter in inlet/outlet valves | Check and clean the inlet/outlet valves |
| Bearings worn | Bearings worn Replace bearings |
| Fluid temperature too high | Reduce the temperature of the pumped fluid |
| Water traces in oil | Excessive leaks caused by totally worn water seals | Replace seals |
| High humidity rate in air | Change oil twice as often as recommended |
| Water seeping from drains between head and crankcase | Water seals worn | Replace seals |
| Piston damaged | Replace piston |
| O-ring on piston bolt worn | Replace O-ring |
| Oil seeping from drains between head and crankcase | Oil seals worn | Replace oil seals |
| Frequent or premature wear of water seals | Pistons damaged or scratched | Replace pistons |
| Abrasive matter in water | Install the proper filter on the inlet side |
| Water temperature too high | Check temperature of inlet water |
| Pump running dry | Avoid running pump without water |
| Operates for long periods in by-pass | Limit by-pass mode running to no more than 5 min |
| Excessive vibrations at outlet hose/pipe | Pulsation dampener drained (where present) | Check pressure in pulsation dampener |
| Valves worn or dirty | Check and replace |
| Pump is sucking in air | Check inlet ducts and make sure they are air-tight |
| Water seals worn | Replace water seals |