Why is my Atlas Copco cooling water outlet temperature high?
Short answer: Cooling water outlet temperature high. If your Atlas Copco GA series, water-cooled (Elektronikon II regulator) is showing Cool Water Out (warning), 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?
On water-cooled compressors, the cooling water outlet temperature exceeded the programmed warning level (nominal 60 degrees C), indicating insufficient cooling water flow or too-warm supply water.
Which machines show this?
water-cooled variants of Atlas Copco's GA rotary screw range in the Elektronikon II era — packages plumbed to a cooling tower, chiller, or plant water loop instead of an air-blast cooler. On these units the controller watches cooling water temperatures in addition to the standard compressor signals, warning nominally at 60 °C on the outlet and 50 °C on the inlet. Messages follow the usual Elektronikon II style: sensor name, live value, and the programmed level. Practical tip: when a water-temperature warning appears, check the whole water path — supply valves, tower or chiller operation, and line restrictions — before suspecting the compressor itself; the machine is usually reporting a plant-water problem, not a compressor fault.
What causes it?
- Cooling water supply valves not fully open
- Cooling water arriving too warm (inlet above its nominal level)
- Kinked or restricted water lines, or the cooling tower/chiller not running
- Scaled water-side cooler passages when flow and supply temperature check out
Can you fix it yourself?
Often, yes — opening valves, restoring flow, and getting supply water temperature back in range fixes most cases without a service call.
Step by step — what to try, in order:
- Check cooling water supply valves are fully open
- Check cooling water inlet temperature (warning level is nominally 50 degrees C on the inlet)
- Look for kinked or restricted water lines and confirm the cooling tower/chiller is running
- Stop the compressor and let it cool if the temperature keeps rising
When do you need a technician — and why?
If flow and supply temperature are normal, the coolers are likely scaled internally, and chemical or mechanical descaling of heat exchangers is professional work.
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 Cool Water Out (warning) mean on an Atlas Copco GA series, water-cooled (Elektronikon II regulator)?
Cooling water outlet temperature high. On water-cooled compressors, the cooling water outlet temperature exceeded the programmed warning level (nominal 60 degrees C), indicating insufficient cooling water flow or too-warm supply water.
Can I fix Cool Water Out (warning) on an Atlas Copco GA series, water-cooled (Elektronikon II regulator) myself?
Often, yes — opening valves, restoring flow, and getting supply water temperature back in range fixes most cases without a service call.
When does Cool Water Out (warning) on an Atlas Copco GA series, water-cooled (Elektronikon II regulator) need a technician?
If flow and supply temperature are normal, the coolers are likely scaled internally, and chemical or mechanical descaling of heat exchangers is professional work. If flow and supply temperature are normal, the water-side of the coolers may be scaled and needs professional cleaning.
Verified against service documentation: Atlas Copco GA series, water-cooled (Elektronikon II regulator) documentation for Cool Water Out (warning) (e-pneumatic.com)