Typically, AL022 doesn't occur in isolation. It is often caused by other issues in the alarm log – for instance, if a compressor is off on overload or if there's no water flow (other alarms), the water will heat up. AL022 is essentially the chiller saying "the water got too warm" because something prevented normal cooling.
If no other alarms are present, the process load might simply be too high for the chiller capacity, or extremely hot ambient conditions reduced performance. The chiller water temperature climbed because it couldn't keep up with demand.
A faulty temperature probe could, in rare cases, feed incorrect high readings to the controller, triggering a false alarm. However, controllers usually have redundancy to verify this.
Since AL022 is often a symptom of another fault, look at the chiller's alarm log for any additional codes. If you see accompanying alarms (e.g. a pump failure, refrigerant alarm, etc.), address those first. Resolving the primary issue will likely fix the high temperature condition.
Ensure the chiller is not undersized or overloaded at that moment. If a sudden high process load caused the temperature spike, you may need to reduce the load or allow the chiller time to catch up. Also check if ambient air temperature around the chiller is exceptionally high or if airflow to the condenser is blocked, as this can reduce cooling capacity.
After addressing any root causes and letting the system stabilize (for example, after other fixes or a cooldown period), reset the AL022 alarm. This alarm is often configured to auto-reset once the water temperature falls back into range, but a manual reset might be needed on some models. Monitor the chiller's outlet water temperature closely after reset.
If high temperature issues persist with no obvious cause, it might be time to check the chiller's general health – clean the condenser coils, ensure refrigerant level is correct (if you have gauges), and verify all pumps/compressors are functioning. Sometimes gradual performance loss (from dirty heat exchangers, for example) can lead to poor cooling.
A professional can decipher whether the high temperature is due to a refrigeration circuit issue (like low refrigerant or compressor inefficiency) or a secondary effect of another failure. There could be hidden problems such as fouled heat exchangers, a refrigerant leak (leading to reduced capacity), or aging components.
If process requirements have increased beyond the chiller's capacity, a technician or chiller specialist can advise on possible upgrades or adjustments. They can also verify that control settings (like setpoints and alarm thresholds) are properly configured.
In the rare event you suspect the temperature sensor is reading incorrectly, a technician should calibrate or replace the probe. Don't ignore a high temp alarm assuming it's a sensor glitch – always have it verified to avoid risking equipment damage.
