McQuay PFS Fault Code E22
McQuay PFS Fault Code E22 is a warning alarm indicating: Chilled water temperature sensor drift. The most common causes include Sensor calibration drift. Estimated repair time: 30-60 minutes (requires sensor replacement and calibration verification). This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Chilled water temperature sensor drift
Brand: McQuay | Model: PFS (Air-Cooled Scroll Chiller) | Code: E22 | Severity: Warning
Observable Symptoms
- Temperature reading on controller display shows abnormal value or dashes
- Chiller may not start or cycles erratically due to incorrect temperature input
What to Check First
Before diving into detailed diagnostics, start with this quick first check:
Probable Causes
- Sensor calibration drift
- Sensor element aging
- Sensor exposed to extreme conditions
Recommended Inspection Steps
- Compare sensor reading to calibrated thermometer
- Perform calibration if adjustable
- Replace sensor if drift is significant
Required Tools & Equipment
- Infrared thermometer or calibrated temperature probe
- Safety PPE (gloves, safety glasses, face shield)
Estimated Repair Time
30-60 minutes (requires sensor replacement and calibration verification)
When to Call a Professional
- If the fault persists after completing all recommended inspection steps
- If you observe unusual noises, vibrations, or oil leaks from the compressor
- If refrigerant charge levels are outside OEM specifications and EPA-certified recovery is needed
- If electrical measurements show voltage imbalance greater than 2% between phases
- If the fault recurs immediately after reset, indicating an unresolved safety condition
- Contact an authorized McQuay service representative for warranty-covered repairs
Related Fault Codes
Other McQuay PFS codes that may be related:
OEM Service Manual Reference
OEM Reference: McQuay PFS Air-Cooled Scroll Chiller Service Manual. Available through Daikin Applied (formerly McQuay) technical support.
Frequently Asked Questions
What does McQuay PFS fault code E22 mean?
Fault code E22 on a McQuay PFS chiller indicates: Chilled water temperature sensor drift. This is a warning alarm that requires diagnostic attention.
What causes McQuay PFS alarm code E22?
Common causes include: Sensor calibration drift; Sensor element aging; Sensor exposed to extreme conditions
How do I fix McQuay PFS error code E22?
Follow the recommended inspection steps below. Start with the quick check, then proceed through each step. If the fault persists after all steps, contact an authorized McQuay service representative.