TUH2/TDH2 - Diagnostic Codes

Trane Gas Furnaces: TUH2/TDH2

Re: Furnace Lockout Codes / Diagnostic Codes

INTEGRATED FURNACE CONTROL - ERROR CODES
Flashing Slow	Normal - No call for heat
Flashing Fast	Normal - Call for heat
On	Replace Control
Off	Check Power
2 Flashes	Lockout due to re-tries or recycles
3 Flashes	Pressure switch fault (open or closed)
4 Flashes	Open limit circuit
5 Flashes	Flame sensed with no call for heat
6 Flashes	Reversed polarity, low voltage or poor ground
7 Flashes	Gas valve circuit error
8 Flashes	Low flame signal
9 Flashes	Check Ignitor, Possible grounding problem

FAULT CODE RECOVERY

On power up, the last 4 faults, if any, will be flashed on the Red LED.

The newest fault detected will flash first and the oldest last.
There will be a 2 second delay between fault code flashes.
Solid Red LED error codes will not be displayed.
The Green LED will be on solid during last fault recovery. At any other time the control is powered, the Green LED indicator light will operate as shown in the table above and the Red LED will flash LitePort data (one flash) every 20 seconds.

Fault Code Reset

The last 4 fault codes can be erased from memory by powering up the control with “G” energized and then applying “R” to the “W1” terminal 3 times within 6 seconds.

The control will acknowledge the reset by turning on the red LED for 2 seconds.