Thermal shutdown — when your compressor’s high-temperature protection kicks in and shuts the unit down — stops production cold. If the underlying cause isn’t fixed, it will happen again.
Here’s what’s causing it, and how to prevent it.
A 25 HP rotary screw compressor produces roughly 18,000 BTU/hour of heat. Without adequate air exchange in the compressor room, ambient temperature climbs and thermal shutdown is eventually triggered.
Fix: Ensure fresh-air intake near the compressor, add exhaust ventilation to move hot air out, and confirm the unit has adequate clearance on all sides.
Oil and air coolers remove heat from the system. When coated with dust, oil mist, or debris, heat transfer efficiency drops and the compressor runs hotter. In dusty environments like woodworking shops, coolers can foul within a single season.
Fix: Clean coolers with compressed air or a suitable solvent — at least annually, more often in dirty environments.
On oil-lubricated compressors, oil carries heat from the compression elements to the cooler. Low oil = less cooling capacity. Wrong oil viscosity = reduced heat transfer.
Fix: Check oil daily. Use only the manufacturer-specified oil type and viscosity.
Worn valves in piston compressors make the unit work harder — generating more heat. A clogged oil separator in a rotary screw compressor creates increased pressure drop that also generates excessive heat.
Fix: Scheduled maintenance catches these before they cause thermal failures.
Motion Air Compressors diagnoses overheating issues on-site with the right tools — not over the phone. We identify whether the problem is ventilation, cooler fouling, oil condition, or mechanical wear, and fix it during the same visit where possible.
My compressor keeps shutting down on hot summer days. What’s wrong?
Hot ambient temperatures push compressors that are otherwise properly maintained into thermal shutdown. The solution is usually improving compressor room ventilation — adding intake and exhaust ventilation sized for the actual heat load. This is a common summer issue in poorly ventilated equipment rooms.
How do I clean a dirty oil cooler on my rotary screw compressor?
Dirty coolers should be cleaned by a qualified technician who can safely use compressed air or appropriate solvents without damaging the cooler fins. Improper cleaning can damage the cooler and create additional problems. Annual cleaning is standard in most environments.
Can high operating temperature damage my compressor oil?
Yes — heat is the primary driver of oil oxidation and viscosity breakdown. A compressor running consistently above its design operating temperature degrades oil faster, increasing the frequency of oil changes needed and accelerating wear on seals and other components.
Ready to get started? Contact Motion Air Compressors today — we come to you across Metro Vancouver, the Fraser Valley, Whistler, Vancouver Island, and throughout BC.
