Trane Furnace System Lockout

Three flashes on the trane furnace control board means that the vent pressure is too high or too low which then activates the pressure switch and causes a lockout.

Trane furnace system lockout.

Your system could be turned off or your unit unplugged. Then reset the furnace. At least the instructions with the new board are a little better than what i had with the first one. The system did the same thing tried twice to turn on but we still do not have 24v at the red and gray wires going into the top of the gas control.

It just runs until you turn the thermostat off. Check all incoming and outgoing vents on the furnace air system including on the furnace and clear away anything that may be blocking the air flow. Turn it back on and the system fires right up. Check gas valve at gas company meter check shutoff valve at furnace and check for other shutoff valves.

It then went into lockout. The furnace will go into lockout sometime in the next 24 hours. Contact the gas company to have gas valve turned on or contact your local trane comfort specialist. About 10 seconds after the hot igniter starts to glow the gas comes.