AL21
FG Wilson
Oil Filter Blockage Detection
Controller displays AL21 – Oil Filter Differential Pressure High (if fitted)
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Clogged engine oil filter, Incorrect oil viscosity, Sludge buildup from extended oil change intervals, Faulty differential pressure switch
How to Fix / Troubleshooting
Safety first: Stop the generator, isolate battery negative, and allow the engine to cool. Have oil absorbent material ready.
- Check service history: If oil and filter have not been changed according to FG Wilson/engine schedule, plan a full oil service.
- Replace oil filter: Drain oil if required, remove the old filter, and install a new genuine filter. Lubricate the new filter seal with clean oil and tighten to the specified torque.
- Refill oil: Top up with the correct grade and quantity of oil. Check level with dipstick.
- Inspect pressure switch: If the filter is new but alarm persists, test or replace the differential pressure switch on the filter head.
- Test run: Clear the alarm and run the engine while monitoring oil pressure and for any leaks around the filter.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Engine Oil Filter
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements