Trane Rooftop Troubleshooting & Error Codes
Trane rooftop air conditioners are known for their efficiency and dependability. In the rare case there’s a problem with your unit, this Trane rooftop troubleshooting and error codes guide explains the meaning of the LED lights so you can better understand why your unit isn’t working properly.
This information is for Trane Voyager 1 rooftop units, such as the YSD series, as well as Precedent™ packaged rooftop units, including the YSC series. Any testing or repairs outlined in this guide will need to be completed by an authorized technician.
LED 1 Is Off - System Failure
The voltage between terminals 6 and 9 on J6, the Refrigeration Module (RTRM), should be approximately 32VDC. If no voltage is present, replace the RTRM.
LED 2 Is Off Or Flashing - Heating Failure
If there’s an issue with the heating system, the number of flashes indicates the cause:
- Light is on - Normal operation
- Light is off - No power or failure
- Light is flashing slowly - Normal operation or heat call
- 1 flash - Communication failure
- 2 flashes - System lockout
- 3 flashes - Pressure switch failure
- 4 flashes - TC01 or TC02 open
- 5 flashes - Flame without gas valve
- 6 flashes - Flame rollout open (Trane Voyager 1 models only)
LED 3 Is Flashing - Cooling Failure
If LED 3 is flashing, there’s an error with the cooling system. There are many possible causes:
- Cooling and heating set point (slide pot) on the zone sensor have failed.
- Zone temperature thermistor ZTEMP on ZTS has failed.
- CC1 or CC2 24 VAC control circuits are open.
- LPC1 has opened on time within the 3-minute minimum during 4 consecutive compressor starts.
LED 4 Is Off Or Flashing - Service Failure
- Light is off - Clogged filter switch has closed.
- Light is flashing - Supply fan proving switch has closed.
If you need more information on how to care for your unit, the large library of Trane manuals on our site is a helpful resource.