Need help with your air compressor?

I help people that work with industrial air compressors to prevent and troubleshoot problems. My whole professional life I have worked with air compressors — for the biggest air compressor manufacturer in the world as an engineer and product specialist, and in engineering jobs where air compressors were vital for the correct operation.

My goal is to share knowledge about industrial air compressors and compressed air systems: to make compressed air understandable for everyone!

Cas · independent, no manufacturer behind this site · since 2003 · About me

What problem are you trying to fix?

Pick the symptom. Each page lists the likely causes, what to check first, and the fix.

• Compressor won't startscrew · piston · diesel
• Low pressure / can't reach setpointany system
• Overheatingscrew · piston · diesel
• Oil in compressed airany system
• Water in compressed airany system
• Pressure dropany system
• Compressor won't loadscrew · diesel
• Safety valve blowsscrew
• Unusual noise / knockingscrew · piston · diesel
• Overload relay tripsscrew · piston
• High energy useany system
• Engine starts then shuts downdiesel

General system problems22 pages · any compressor Rotary screw compressors44 pages Reciprocating (piston)53 pages Portable diesel60 pages

Got a rotary screw compressor and want to fix problems quickly? Get my Air Compressor Troubleshooting Guide — the complete reference for diagnosing and fixing rotary screw compressor problems.

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Buying a compressor?

Three decisions: what type, what size, and who's going to service it. Plus the lifetime cost nobody tells you about.

• Which type of compressor do I need?
• Rotary screw compressor buying guide8 topics
• Piston compressor buying guide3 topics
• Pressure vs capacity — sizing it right
• Buying your first proper compressorscenario
• Brands, series & modelsdatabase

Learn how compressed air works

• Compressed air basicsunits, FAD, pressure drop, rules of thumb
• Compressor typesscrew, piston, scroll, diesel
• Air compressor parts11 pages
• Compressed air qualitydryers, filters, classes
• Piping and components
• Articles

• Compressor shut off will not start.Answered Jan 2026
• cat with low compressionAnswered Jan 2026
• Maximum Temperature limitation for screw air-endAnswered Jan 2026
• devilbiss IRL6560VAnswered Jan 2026
• Temperature Alup Largo160Answered Jan 2026

Can't find yours? Ask your question — I answer in the open, so everybody learns from it.