What does Kaeser warning 0071 W (oil level low) mean?
Short answer: Cooling oil level too low. If your Kaeser Sigma Control 2 is showing 0071 W — Oil level ↓, the controller has logged a specific, documented condition. This page covers what it means, what causes it, what you can safely fix yourself, and when — and why — it takes a technician.
What exactly is the machine telling you?
The cooling oil level is too low. The documented remedy is to replenish the cooling oil.
Which machines show this?
the wide range of current-generation Kaeser rotary screw compressors — ASD, BSD, CSD, DSD, ESD and related series — built since roughly 2011 with the Sigma Control 2, the industrial-PC controller with a text display and RFID access. It reports faults as a four-digit number plus a letter: 'A' messages are alarms that shut the machine down, 'W' messages are warnings or service reminders it keeps running through, with arrows marking whether the value went over or under its limit — so 0015 A is the airend-overheat shutdown while 0013 W just asks for an air filter. Practical tip: the same subsystem often has a W and an A code (0004 W before 0022 A on the separator); acting on the W message is how you avoid the A shutdown.
What causes it?
- Cooling oil level low — replenish is the documented remedy
- The unit consuming or leaking oil if the level keeps dropping
Can you fix it yourself?
Yes — shut down, let it depressurize per the manual, check the sight glass, and top up with the approved fluid.
Step by step — what to try, in order:
- Shut the machine down and let it depressurize per the operator manual before checking.
- Check the sight glass and top up with the approved Kaeser cooling fluid.
- Recheck after a short run.
When do you need a technician — and why?
A level that drops repeatedly means oil is going somewhere — consumption or a leak that service needs to trace before it becomes a temperature trip.
If it does come to a service call and you're in Nashville, TN or Birmingham, AL, we maintain independently compiled lists of local companies that service industrial air compressors — real businesses with verified contact information, none of whom paid to be listed.
Related questions
What does 0071 W — Oil level ↓ mean on a Kaeser Sigma Control 2?
Cooling oil level too low. The cooling oil level is too low. The documented remedy is to replenish the cooling oil.
Can I fix 0071 W — Oil level ↓ on a Kaeser Sigma Control 2 myself?
Yes — shut down, let it depressurize per the manual, check the sight glass, and top up with the approved fluid.
When does 0071 W — Oil level ↓ on a Kaeser Sigma Control 2 need a technician?
A level that drops repeatedly means oil is going somewhere — consumption or a leak that service needs to trace before it becomes a temperature trip. If the level drops repeatedly, call service — the unit may be consuming or leaking oil.
Verified against service documentation: Kaeser Sigma Control 2 documentation for 0071 W — Oil level ↓ (airsolcan.com)