What does Gardner Denver advisory 302 change air filter mean?
Short answer: Inlet air filter restricted. If your Gardner Denver AirSmart controller is showing ADVISORY #302 CHANGE AIR FILTER, 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 vacuum switch after the inlet air filter tripped, indicating the filter is dirty enough to restrict airflow.
Which machines show this?
Gardner Denver rotary screw compressors fitted with the first-generation AirSmart microprocessor controller — a wide range of oil-injected packages, including VFD-equipped variable-speed units where the controller supervises the drive. The first-generation AirSmart reports problems as numbered codes: SHUTDOWN #1xx and #2xx faults that stop the machine, and ADVISORY #3xx warnings that let it keep running while flagging maintenance. That numbering matters when you search — the later AirSmart G2 dropped the numbers and displays plain-text fault names instead, so a numbered code on the screen tells you that you are on the earlier controller. Shutdowns clear with Stop/Reset once the machine has stopped; advisories acknowledge with the Enter key.
What causes it?
- The inlet air filter is dirty enough to trip the vacuum switch behind it
- Dusty plant air loading the filter faster than the service interval assumed
- Something else restricting the inlet if the advisory returns right after a new filter
Can you fix it yourself?
Yes — this is one of the few genuinely DIY items: shut the machine down completely and swap in the correct GD inlet filter element, then press Enter to reset.
Step by step — what to try, in order:
- Shut the machine down and let it stop completely
- Replace the inlet air filter element with the correct GD part
- Press Enter on the controller to reset the advisory
When do you need a technician — and why?
If a brand-new filter trips the advisory again quickly, the restriction is somewhere else in the inlet tract, and finding it means inspecting the inlet valve and ducting on a locked-out machine.
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 ADVISORY #302 CHANGE AIR FILTER mean on a Gardner Denver AirSmart controller?
Inlet air filter restricted. The vacuum switch after the inlet air filter tripped, indicating the filter is dirty enough to restrict airflow.
Can I fix ADVISORY #302 CHANGE AIR FILTER on a Gardner Denver AirSmart controller myself?
Yes — this is one of the few genuinely DIY items: shut the machine down completely and swap in the correct GD inlet filter element, then press Enter to reset.
When does ADVISORY #302 CHANGE AIR FILTER on a Gardner Denver AirSmart controller need a technician?
If a brand-new filter trips the advisory again quickly, the restriction is somewhere else in the inlet tract, and finding it means inspecting the inlet valve and ducting on a locked-out machine. Call for service if the advisory returns quickly after a new filter — something else may be restricting the inlet.
Verified against service documentation: Gardner Denver AirSmart controller documentation for ADVISORY #302 CHANGE AIR FILTER (best-aire.com)