06 03 APS open

What the control is telling you

Air pressure switch (APS) is open. Reset to clear.

Applies to: TRX150

Likely causes

• Loose APS or controller connection
• Faulty APS
• Damaged or disconnected APS hose
• Blocked condensate line or exhaust vent

Test and repair steps

1. Press Reset to clear the code.
2. Check the APS and main controller connections. Make sure all are secure.
3. Check the APS resistance. If it is not zero, replace the switch.
4. Check the APS hose. Make sure it is connected and in good condition.
5. Check the condensate line and termination for blockages.
6. Check the exhaust vent for blockages.
7. If the problem continues, replace the main control.

Models that show this code

5 models in TRX

Other codes on the same units

• 05 04 10 flame lifts in one operating cycle
• 5 P1 1st ignition failed
• 5 P2 2nd ignition failed
• 5 P3 Flame loss during run
• 5 P6 3rd and 4th ignition failed
• 06 02 Exhaust temperature above 204 °F (96 °C)
• 06 05 Exhaust NTC circuit open or short circuit
• 6 12 Insufficient fan speed