McQuay PFS Fault Code E07
McQuay PFS Fault Code E07 is a critical safety alarm indicating: Freeze protection activated. The most common causes include Evaporator water temperature near freezing. Estimated repair time: 1-2 hours. This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Freeze protection activated
Brand: McQuay | Model: PFS (Air-Cooled Scroll Chiller) | Code: E07 | Severity: Critical
Observable Symptoms
- Evaporator water temperature reads below 40F (4.4C)
- Frost or ice visible on evaporator or water lines
- Chiller has shut down on freeze protection safety
What to Check First
Before diving into detailed diagnostics, start with this quick first check:
Probable Causes
- Evaporator water temperature near freezing
- Water flow too low
- Setpoint too low
Recommended Inspection Steps
- Check water temperature
- Verify flow rate
- Raise setpoint above 40F
- Check antifreeze concentration
Required Tools & Equipment
- Infrared thermometer or calibrated temperature probe
- Safety PPE (gloves, safety glasses, face shield)
Estimated Repair Time
1-2 hours
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 E07 mean?
Fault code E07 on a McQuay PFS chiller indicates: Freeze protection activated. This is a critical safety alarm that requires diagnostic attention.
What causes McQuay PFS alarm code E07?
Common causes include: Evaporator water temperature near freezing; Water flow too low; Setpoint too low
How do I fix McQuay PFS error code E07?
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.