What does Kaeser warning 0046 W (system pressure low) mean?
Short answer: Network pressure below low-pressure warning value. If your Kaeser Sigma Control 2 is showing 0046 W — System pressure ↓, 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?
Plant network pressure fell below the configured "network pressure low" value — often air demand exceeding supply, or a leak.
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?
- Air demand exceeding supply — new tools, open drains, or leaks
- A leak somewhere on the network
- Low-pressure warning setpoint configured unrealistically
Can you fix it yourself?
Often, yes — walk the line for leaks, review what demand changed, and sanity-check the setpoint.
Step by step — what to try, in order:
- Check whether air demand has increased (new tools, open drains, leaks).
- Verify the low-pressure warning setpoint is set sensibly.
- Walk the line for audible leaks.
When do you need a technician — and why?
If pressure stays low with normal demand, the sensor, line paths, or actual compressor capacity need professional checking — capacity problems don't fix themselves.
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 0046 W — System pressure ↓ mean on a Kaeser Sigma Control 2?
Network pressure below low-pressure warning value. Plant network pressure fell below the configured "network pressure low" value — often air demand exceeding supply, or a leak.
Can I fix 0046 W — System pressure ↓ on a Kaeser Sigma Control 2 myself?
Often, yes — walk the line for leaks, review what demand changed, and sanity-check the setpoint.
When does 0046 W — System pressure ↓ on a Kaeser Sigma Control 2 need a technician?
If pressure stays low with normal demand, the sensor, line paths, or actual compressor capacity need professional checking — capacity problems don't fix themselves. Call service if pressure stays low with normal demand — sensor, line paths, or compressor capacity need professional checking.
Verified against service documentation: Kaeser Sigma Control 2 documentation for 0046 W — System pressure ↓ (airsolcan.com)