Trane RTAC Fault Code C5
Trane RTAC Fault Code C5 is a warning alarm indicating: Low Chilled Water Temperature: Unit Off. The most common causes include Chilled water setpoint too low. Estimated repair time: 30-60 minutes (requires sensor replacement and calibration verification). This alarm requires immediate attention by a certified HVAC technician.
Alarm Description
Low Chilled Water Temperature: Unit Off
Brand: Trane | Model: RTAC (Screw Compressor Chiller) | Code: C5 | Severity: Warning
Observable Symptoms
- Controller displays alarm code and description
- Chiller may be locked out or running in degraded mode
- Alarm indicator light is illuminated on control panel
What to Check First
Before diving into detailed diagnostics, start with this quick first check:
Probable Causes
- Chilled water setpoint too low
- Evaporator water flow too low
- Sensor reading incorrect
- Building load very low
Recommended Inspection Steps
- Verify chilled water setpoint is appropriate
- Check evaporator water flow rate
- Calibrate or replace water temperature sensor
- Increase load or raise setpoint
- Check bypass valve operation
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 Trane service representative for warranty-covered repairs
Related Fault Codes
Other Trane RTAC codes that may be related:
OEM Service Manual Reference
OEM Reference: Trane RTAC Air-Cooled Rotary Screw Chiller Service Manual (SVR-SVN001-EN). Available through Trane Commercial support.
Frequently Asked Questions
What does Trane RTAC fault code C5 mean?
Fault code C5 on a Trane RTAC chiller indicates: Low Chilled Water Temperature: Unit Off. This is a warning alarm that requires diagnostic attention.
What causes Trane RTAC alarm code C5?
Common causes include: Chilled water setpoint too low; Evaporator water flow too low; Sensor reading incorrect
How do I fix Trane RTAC error code C5?
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 Trane service representative.