What does High Air Filter dP mean on a Sullair compressor?
Short answer: Inlet air filter restricted. If your Sullair Touch Screen (STS) is showing High Air Filter dP, 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 pressure differential across the inlet air filter is high, meaning the filter element is dirty or plugged and needs to be checked or changed.
Which machines show this?
current-generation Sullair stationary rotary screw compressors — the LS-series and related packages built from the late 2010s onward — fitted with the 10-inch Sullair Touch Screen (STS) controller. The STS spells out problems as plain-English named faults and warnings ('High Temperature 1', 'Failed to Unload', 'Replace I/O Battery') rather than bare code numbers, and pairs them with live readings and a Recommended Service screen that tracks filter and separator hours. Warnings keep the machine running; faults shut it down until reset. Practical tip: before clearing anything, photograph the fault screen and the Recommended Service page — the service-hour counters usually point straight at the consumable that caused the trip.
What causes it?
- Inlet air filter element dirty or plugged
- Excessively dusty intake environment loading filters early
Can you fix it yourself?
Yes — stop the unit, inspect and replace the element, improve intake air quality if you can, and reset the service reminder. Routine work.
Step by step — what to try, in order:
- Stop the unit and inspect the inlet air filter element
- Replace the air filter element if dirty
- Check the environment for excessive dust and improve intake air quality if possible
- Reset the service reminder on the Recommended Service screen after replacement
When do you need a technician — and why?
Only a warning that returns quickly on a fresh filter needs service, to test the inlet filter pressure switch or sensor instead of wasting filters.
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 High Air Filter dP mean on a Sullair Touch Screen (STS)?
Inlet air filter restricted. The pressure differential across the inlet air filter is high, meaning the filter element is dirty or plugged and needs to be checked or changed.
Can I fix High Air Filter dP on a Sullair Touch Screen (STS) myself?
Yes — stop the unit, inspect and replace the element, improve intake air quality if you can, and reset the service reminder. Routine work.
When does High Air Filter dP on a Sullair Touch Screen (STS) need a technician?
Only a warning that returns quickly on a fresh filter needs service, to test the inlet filter pressure switch or sensor instead of wasting filters. Call service if the warning returns quickly after a new filter — the inlet filter pressure switch or sensor may be faulty.
Verified against service documentation: Sullair Touch Screen (STS) documentation for High Air Filter dP (sullair.com)