Green Flow Solution logo
Schedule Service

Troubleshooting code

Back to all 5TWX6018A1 error codes

Trane 5TWX6018A1 3 Flashes troubleshooting

Low pressure switch is open. Use this page to document the issue and prepare for service. GreenFlow should handle diagnosis for electrical, refrigerant, lockout, or recurring conditions.

Schedule Service +1 (857) 767-6414

What the code means

3 Flashes: Low pressure switch is open

The Trane defrost control indicates the low pressure switch is open. This can involve refrigerant-side or operating-condition issues that require a technician.

System area
Pressure safety circuit
Service level
Call GreenFlow

Safe checks before calling

  • Confirm the thermostat is on, set correctly, and calling for heating or cooling.
  • Check the air filter and visible return-air path for obvious airflow restrictions.
  • Look around the outdoor unit for leaves, snow, ice, or other visible obstructions without opening the cabinet.
  • Take photos of the thermostat, outdoor unit, nameplate, and any visible flash pattern before scheduling service.

When to stop and call GreenFlow

Call GreenFlow if the code repeats, the system is locked out, heating or cooling is not restored, there is ice buildup, electrical odor, unusual noise, or any issue involving pressure switches, sensors, wiring, refrigerant, reversing-valve operation, or warranty coverage.

Share the visible code, model and serial number if available, photos, current symptoms, and whether the issue affects heating, cooling, or both.

3 Flashes questions

What does 3 Flashes mean on a Trane 5TWX6018A1?

The Trane defrost control indicates the low pressure switch is open. This can involve refrigerant-side or operating-condition issues that require a technician.

What should I safely check before scheduling service?

Check thermostat status, filter condition, visible outdoor-unit obstructions, and take photos of the flash pattern and nameplate. Do not open electrical panels or refrigerant-side components.

When should GreenFlow handle this code?

Call GreenFlow if the code repeats, the system is locked out, heating or cooling is not restored, there is ice buildup, electrical odor, unusual noise, or any issue involving pressure switches, sensors, wiring, refrigerant, reversing-valve operation, or warranty coverage.

Need help with this code?

GreenFlow can review the code, photos, equipment access, and symptoms before scheduling the right next step.

Schedule Service Back to product

Brands We Service

Popular cities

Service Areas

Our Happy Customers

Jenny W.

Great service! On time, knowledgeable & professional

Jahangir R.

They were very organized to communicate and be on time to come to look at my air condition to fix it.

Anna G.

They quickly identified the issue with the heating system and fixed it efficiently. He explained everything clearly and made sure I understood what was going on. Very professional and reliable, extremely satisfied with the service.

Terry S.

Excellent service from best tech!

View All