Trane Furnace Red Light Flashing 3 Times [5 Easy Fixes]

The Trane furnace red light flashing 3 times is a common occurrence that the users face. It is an indication that there is a pressure switch failure in the Trane furnace. 

trane furnace red light flashing 3 times

The issue typically occurs when there is a blockage in the exhaust vents, a rusty or jammed pressure switch, or a faulty sensor. In addition to these reasons, loose wiring and a damaged hose also contribute to the issue. 

Quick Solution: The instant and primary solution to fix the Trane furnace flashing 3 times is to reset the furnace and check if it’s working. If resetting won’t work, then be sure the above-mentioned reasons are the culprits and you need to explore them. 

Here to find the reasons and solutions, go on reading. Below, we will sort out them with simple solutions. 

Note: You can also read how to fix Trane Furnace’s all-red light flashing problem.

Table Of Contents

What Is A Pressure Switch

As you already know, the pressure switch error is the main culprit behind the red light blinking 3 times. So, before we get into a detailed discussion of why the problem occurs, let’s know a bit about the pressure switch and how it works. 

pressure switch

You know, in every furnace, the pressure switch is a vital part that works as a safety feature. The purpose of the pressure switch is to ensure that the furnace is operating without any problems.

It will shut off all the operations of the furnace if the pressure switch senses any sort of negative pressure and flash red light 3 times. 

How Does The Pressure Switch Work

When the furnace is turned on and the fan starts rotating, the hose connected to the pressure switch pulls a vacuum inside which the sensor detects.

If the sensor detects the pressure properly, the pressure switch closes which completes the sensor and allows the power to move toward the ignitor. The ignitor then heats up the furnace; thus increasing the temperature of the room. 

However, if the pressure switch senses a negative temperature, then the circuit will remain open and incomplete. This means that the power won’t go through the ignitor and will result in the Trane furnace not working. 

Trane Furnace Red Light Flashing 3 Times [5 Easy Fixes]

Here, we will discuss each and every possible reason that results in the Trane furnace red light blinking 3 times. Take a look at the reasons and the solutions behind the problem. 

1. Exhaust Vent Blockage

One of the top reasons why the pressure switch fails in the Trane furnace is due to a blockage in the exhaust vent.

Exhaust Vent

If the exhaust vents are blocked, the air is trapped within the furnace which in turn contributes to negative pressure in the furnace. 

Leakage in the exhaust vent pipes also contributes to the issue. The pressure switch senses the incorrect pressure and does not let the power pass through the ignitor. 

Solution

Turn the furnace off and examine the exhaust vent properly. Make sure that the pipes are clean and the vents are not blocked in any way. Clean the pipes and clear the path of the exhaust vents. 

Do not forget to check the exhaust pipes for leaks and cuts. Repair the leakage or cuts properly and turn on the furnace to ensure that it’s working properly. 

2. Jammed Pressure Switch

Another common reason why the Trane furnace red light flashes 3 times is a jammed pressure switch. Over time, rust, dirt, debris, and other impurities accumulate over the pressure switch and cause it to jam.

This prevents the switch from working and doesn’t close the sensor properly even after it detects the right pressure conditions. 

Solution

Remove the main connection to the furnace and check the pressure switch to ensure that it’s working properly.

Clean the dirt, debris, and so on, and turn the furnace back on. Replace the pressure switch with a new one if the Trane furnace isn’t working even after cleaning the switch. 

3. Malfunctioning Sensor

A malfunctioning sensor also results in the Trane furnace flashing 3 times. When the furnace is turned on, the sensor closes and completes the circuit in order to power the ignitor.

 malfunctioning sensor

If the sensor is damaged in any way, then it won’t be able to close the circuit properly thus, resulting in the red light flashing 3 times. 

Solution

Open the furnace and take a proper look at the sensor connected to the pressure switch. Examine and ensure that it’s in perfect working condition.

Repair or replace the sensor if you identify any damage and turn the furnace back on. 

However, if you are unable to identify the error, take help from a certified professional to detect the problem properly. 

4. Loose Wiring

The wires connected to the pressure switch in the Trane furnace play a major role in the operations of the furnace.

loose wiring

If the wires are loose from their connecting point, then they won’t be able to send the required signals to the pressure switch, thus preventing it from working efficiently. 

Solution

Turn the furnace off and open the control board. Examine the wiring connected to the pressure switch with the help of the Trane furnace manual.

Connect the wires securely in the proper position and close the control board. Turn the furnace on to ensure that it’s efficiently performing. 

5. Damaged Hose

Last but not least, a damaged hose also causes the red light to flash 3 times in the Trane furnace. When the furnace is turned on, the hose pulls the vacuum and signals the pressure switch to close the sensor and complete the circuit. 

If the hose connected to the pressure switch is damaged, then it doesn’t provide a proper service which in turn prevents the sensor from closing.

Now, this typically happens when there is dust accumulated in the hose or rust has built up between the joining tip of the hose and the switch. Leakage in the hose also prevents proper performance. 

Solution

Turn the furnace off and take a look at the hose connected to the pressure switch. Disconnect the hose from the furnace and clean it properly.

Remove the rust from the joining part and ensure that there is no dirt, debris, etc. present. Repair or replace the entire hose if you notice any leakage or cuts on the hose. 

How To Replace Pressure Switch In Trane Furnace

The process of replacing the Trane furnace pressure switch is quite simple and doesn’t require more than a few minutes. The steps in the pressure switch replacement procedure are as follows:

  • Turn off the furnace and unplug it from the power outlet. 
  • Remove the hose and disconnect the pressure switch by unwiring the two wires connected to it. 
  • Take the new pressure switch and place it in place of the old one and secure it properly by tightening the wires to it. 
  • Connect the hose back to the pressure switch properly. 
  • Plug the furnace back in and turn it on to see the furnace heating up and warming up your room. 

FAQs:

What Happens If The Trane Furnace Red Light Is Flashing Constantly?

There is nothing to worry about if the Trane furnace red light is flashing constantly. It is an indication that the Trane furnace is operating smoothly and in proper condition. 

When the Trane furnace red light flashes 2 times, it means that the system is in a lockout. Resolve it by resetting the furnace or fixing the problem causing the lockout. 

Conclusion

We have discussed each and every possible reason along with the solution that results in the Trane furnace red light flashing 3 times. At the end of the guide, I hope you now know how to resolve the issue on your own when you encounter a pressure switch error. 

If you have any questions or queries about the Trane furnace, make sure to drop a comment in the box below. We will get back to you as soon as we can with the best possible answer to your query. 

About David

David is a man who loves doing research and finding out the best solution to any type of heating appliance issues like heaters and fireplaces. Whenever he finds the perfect solutions to any issues of heating appliances after doing in-depth research, he loves to share them with his readers. In fact, his aim is to help his readers to fix the issues with their heating appliances easily.More about us .

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