Trane Error Code 3: Pressure Switch Error

LED Blink Pattern

How to Fix Trane Code 3

1. Check for any visible signs of refrigerant leaks, such as frost or oil residue on the lines.
2. If you find a leak, mark the location and contact a professional HVAC technician immediately.
3. 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

1. Turn off the furnace power switch, usually located on or near the unit.
2. Turn off the circuit breaker for the furnace. Wait 30 seconds.
3. Restore power at the breaker and flip the furnace switch back on.
4. Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Trane Error Code 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.

Common Causes

• A refrigerant leak, which can be caused by a damaged line or a leaky component in the system.
• A faulty pressure switch, which may need to be replaced.
• A problem with the system's expansion valve, which could be clogged or faulty.

Diagnostic Steps

Replacement Parts

Related Codes on Same Models

Other codes that affect the same Trane model families as 3.