We will show you how to troubleshoot some common problems with your trane gas furnace. The goal of this troubleshooting guide is to give you a better understanding of what can go wrong with your trane furnace, what repairs might help and when you should call a professional.
First we will look at some of the simple solutions and then we’ll go step-by-step through the sequence of operation and the individual repairs.
Does the furnace cycle on and off?
If the trane furnace ignites and the blower fan is running but there’s no heat coming out of the unit, then something might be restricting the airflow. Turn off your furnace and check the filter. The air filter is located next to the cold air return duct. As the filter collects dust it begins to restrict the airflow, this is why it’s essential to replace the filter every three to six months. If replacing the filter doesn’t help, there might be something else clogging the ducts. So it might be worth a professional inspection.
If your trane furnace isn’t running at all, it’s best to eliminate the simple solutions. First take a look at your thermostat, check the batteries and replace them if necessary. Now make sure that the thermostat is set to heat and the fan is set to auto.
Next check the breaker box, if the furnace breaker is tripped and in the middle position then flip the breaker all the way off and then flip it on to reset the breaker. Locate the power switch on the side of the furnace and make sure that the switch is on. Now find the gas shut-off valve, it should be open. Also many furnaces have a safety switch that prevents the furnace from running when the blower cover is open, so make sure that the cover is closed all the way.
New trane furnace model have a set of safety switches that shut down the furnace when the system is compromised. If a switch is tripped it will cause the furnace to lockout. The unit will attempt ignition several times before going into a hard lockout for up to an hour. Every time a lockout happens, the furnace will use flashing lights as codes to identify the source of the shutdown. These codes are unique to each model so check your trane manual to see what each code means.
Now if you are going to repair trane furnace, know your limits and only a temple you can safely do if your furnace has power then turn on the thermostat and observe the startup sequence first. The draft inducer fan pulls air through the heat exchanger. This ensures that all fumes are exhausted during combustion if the inducer isn’t running then the motor might be seized or burn out. Additionally the wires could be faulty or it could be a problem with the control board if the inducer is running and there’s enough airflow to remove the exhaust gasses. Then the pressure switch will close when the pressure is low. The switch will stay open and will prevent the furnace from igniting.
Try to identify anything that might cause a change of pressure inside the heat exchanger. Check to see if there’s any obstructions in the flue vent or in the inducer motor port.
Does the ignitor glow?
Next check to see if there are any blockages in the pressure switch tubing. If the airflow is good and the pressure switch might be faulty. If the pressure is good then voltage is sent to the hot surface igniter.
Some trane furnace series might use a spark igniter instead. If the igniter doesn’t activate then remove the igniter and test for continuity. If the igniter doesn’t have continuity it will need to be replaced. If the igniter has continuity but still doesn’t ignite then it might be a problem with the wires or the control board as the igniter glows the gas valve will open and the burners will ignite.
Is the flame sensor faulty?
There’s no flame present then check to see if the gas valve is on. If there’s still no flame then you should call a professional. As the gas valve solenoid could be faulty or there could be low gas pressure. The flame sensor checks to see if a flame is present. If all the burners light the flame should stay on for more than seven seconds. If the burners shut off shortly after igniting, the flame sensor could be dirty or defective. Remove the sensor and clean it with a soft abrasive pad. If the flame still doesn’t stay on then replace the flame sensor.
Look for any scorch marks as this indicates a more serious problem. If the flames roll out the front of the burner the flame roll out switch shuts off the furnace. These switches usually have a reset button. If you reset the switch and the switch keeps tripping then shut your furnace off and call a professional.
The heat exchanger could be cracked and could be releasing carbon monoxide into your home. If there’s no sign of a flame roll out then the flame roll out switch might be defective test the switch for continuity. If there is no continuity then replace the flame rollout switch, if there’s continuity and the flame still doesn’t stay lit then call a professional.
Does the blower fan run?
When the burner is lit the blower fan is too late from running to allow the heat exchanger to warm up this prevents the furnace from circulating cold air. If the blower motor still doesn’t run after a minute or two then the motor might be seized or burnt-out the limits which monitors the temperature of the air passing over the heat exchanger and will shut off the furnace if the system overheats. Any restriction of the airflow might cause the heat exchanger to overheat. This is why it’s essential to replace the furnace filter every three to six months. If the airflow is good and the blower fan cycles on and off then the limits which could be defective.
Let us know what trane furnace repairs you’d like to know next. And if you have any question, feel free to cantact me.