Trane Error Code 3: Pressure Switch Error
Warning: Your Trane HVAC system has detected a pressure issue and has shut down to prevent damage.
How to Fix Trane Code 3
- Check for any visible signs of refrigerant leaks, such as frost or oil residue on the lines.
- If you find a leak, mark the location and contact a professional HVAC technician immediately.
- If there are no visible leaks, the problem may be with the pressure switch or expansion valve. These components should be inspected and potentially replaced by a professional.
How to Reset Trane Code 3
- Turn off the furnace power switch, usually located on or near the unit.
- Turn off the circuit breaker for the furnace. Wait 30 seconds.
- Restore power at the breaker and flip the furnace switch back on.
- Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.
What does 3 mean?
Error code 3 on your Trane HVAC system indicates a problem with the system's pressure switch. The pressure switch is responsible for monitoring the refrigerant pressure in your system. If it detects a pressure that's too high or too low, it triggers this error code and shuts down the system to prevent further issues. This error is typically caused by a refrigerant leak, a faulty pressure switch, or a problem with the system's expansion valve.
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Pressure Switch | Trane 75-0001 | — |
| Expansion Valve | Trane 75-0002 | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| STEADY-ON | Control Board Problem | Warning |
| STEADY-OFF | No Power | Warning |
| SLOW-FLASH | Normal Operation (Standby) | Warning |
| FAST-FLASH | Active Call for Heat | Warning |
| 2 | System Lockout | Warning |
| 4 | Open Limit Switch | Warning |
| 5 | Flame Sensed With Gas Off | Warning |
| 6 | Polarity/Grounding Error | Warning |
| 7 | Gas Valve Circuit Error | Warning |
| 8 | Low Flame Signal | Warning |