Gas Furnace: TUX/TDX 2-Stage Re: Flashing Code 3 / Inducer Fan Not Running Code 3 = Pressure switch fault There are two pressure switches on this furnace, one for low speed fan and one for high speed. A Code 3 will result from either of the following conditions: Pressure switch contacts...

Gas Furnace: TUX1/TDX1 Re: Flashing Code 3 Code 3 = Pressure switch fault A Code 3 will result from either of the following conditions: Pressure switch contacts "closed" when they should be open. Pressure switch contacts "open" when they should be closed. ► If the pressure switch is...

Gas Furnace: TUX Re: Flashing Code 4 Code 4 = Open Limit Circuit There are three limits in the limit circuit: Main Limit (TCO-A) - Automatic-reset limit for the heat exchanger. Roll-Out Limit - Manual-reset limit mounted above burners. Auxiliary Limit (TCO-B) - Automatic-reset limit,...

Trane Gas Furnaces: TUX2/TDX2 Re: Furnace Lockout Codes / Fault Codes INTEGRATED FURNACE CONTROL - ERROR CODES On Internal GV error or low TH voltage Off Check Power 2 Flashes Lockout due to re-tries (flame failure) 3 Flashes Pressure switch fault (open or...