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Why Is Carrier Furnace Blinking Yellow, Red, or Orange?

A furnace is a device that uses combustion to generate heat. The furnace is the unsung hero of your home, working tirelessly behind the scenes to maintain a cozy environment for you and your family all year long.

On the front of the furnace are a few lights that serve various purposes. The furnace’s small light at the base is known as the “blinking light.” Nonetheless, the wired configuration can reveal information about the codes.

Now, let us find out why carrier furnaces blink yellow, red, and orange lights and also discuss some fascinating information related to carrier furnaces.  

Carrier furnace blinking yellow, red or orange 

When the light on your furnace rapidly blinks yellow, red, or orange, it means that there is a problem inside the furnace that requires immediate treatment. Furnaces’ lights can flicker in a variety of circumstances. You must ascertain the cause of this and take the appropriate action in response.

Let’s find out the reason behind blinking different colors of light in your carrier furnace –  


Issues with gas valve solenoid:

If the gas valve solenoid isn’t working right, which can cause the furnace to get stuck in high fire mode, the yellow indicator light will start flashing. 

Sometimes, if everything is working right and the thermostat says that cooling is needed, the yellow light will start blinking. 

High-pressure switch:

Sometimes, the furnace cannot be reset because of an issue with the high-pressure switch. As a result, it lights up the yellow light in the furnace. 

There may be a problem with the air pressure if the condenser coils of the furnace are dirty or if there is a problem with the high-pressure switch.

Lack of gas flow: 

Sometimes, after three attempts, the high-pressure switch might flip, which will stop any gas flow to the burner. As a result, it will begin flashing a yellow light. If the burners still do not light, the switch will repeat the process.


Tripped circuit breaker: 

If the circuit breaker that controls the furnace has been tripped, the light will flash red, and the furnace will not be able to heat the room. 

Also, it’s possible that the blower motor is being put under too much stress because air vents all over the house are blocked.

Loose connection or wiring: 

When your furnace is flashing red lights, it means that your thermostat isn’t signaling your furnace. 

Wall wires or a loose connection may cause this problem. If this happens, check for loose connections. If everything looks good, get a new thermostat. Also, a blinking red furnace light could indicate a voltage problem.

Issues with the igniter:

The number of non-working gas burner fins can be determined by starting the furnace. If you have ignition problems, replace or fix the igniter. If any of these occur, the light blinks red.


Inappropriate mix of gas and oxygen: 

When an orange light doesn’t blink steadily and starts flickering, it indicates that the furnace isn’t producing the correct ratio of gas to oxygen in the combustion process.

Air pressure:

If the furnace’s condenser coils are dirty or there is a problem with the high-pressure switch, there may be an issue with the air pressure which might cause the orange color in the furnace.

High-pressure switch:

Sometimes the high-pressure switch fails and the furnace cannot be restarted due to technical issues. As soon as that happens, it starts blinking an orange light, just like the yellow light.

What does a solid red light mean on a carrier furnace? 

On top of your furnace, there is a tiny red light for your convenience. If the light continues to glow steadily, it indicates that your heater is operating correctly.

There are a few different kinds of lights that will come on if there is a problem with your furnace.

In addition to this, there is yet another explanation for why the light on the furnace is solid red. It’s possible that a red light will be lit up on the burner unit of your oil furnace if it won’t turn on.

When you see this red light, which is also known as a lockout light, it might also indicate that a safety mechanism on your furnace has caused it to shut down because it has found a problem or recognized a fault and thus shut it down.

What does a yellow, red and orange blinking light mean on a carrier furnace?

When the furnace’s indicator light flashes rapidly, it’s trying to get your attention in an emergency situation. Let’s find out.


3 times:

If you see 3 flashes of yellow, this indicates that there is no cause for concern and that your furnace is simply finishing a cycle that it started recently.

4 times:

If your carrier furnace displays a total of 4 yellow blinks, this indicates that the heating capacity of your system may be limited to some degree. It is also letting you know that the switch for the high limit is not closed.

5 times:

If your furnace displays 5 yellow flashes, this indicates that either the vent or the combustor’s air system is congested.


3 times:

A pressure switch that has been opened is indicated by 3 red flashes.

4 times:

If the light on your furnace blinks 3 times in quick succession, it is trying to tell you that the high-pressure push button is not closed.

5 times:

In most cases, a rollout switch or an auxiliary limit switch is open when it is indicated by 5 red lights that blink in sequence.


3 times:

If the furnace has a problem with the pressure switch circuit, you will see a 3-flash warning. Unless otherwise specified by the manufacturer, this is true for virtually all heating systems. 

This indicates that the pressure switch is in the open position when it should be in the closed position.

4 times:

If the light on your furnace flashes four times in rapid succession, this indicates that the high limit switch is not closed. In most cases, the flashing will start, but the furnace will turn off just before it does. 

Alternatively, the fan can operate even when the burner is turned off. As a result, the air that comes out of your ducts will either be cool or at room temperature.

How do you fix a blinking carrier furnace? 

You are being prompted to act by the blinking light that is either yellow, red, or orange. The difficulties that arise in situations like these have already been covered in our conversation. Let’s examine the problem from a step-by-step perspective now.

Make sure the safety: 

Make sure you or anyone else in the house is safe before doing anything else. This is very important because gas leaks are sometimes present when the lights start blinking. Maintain a safe environment.

Turn off the furnace: 

It is imperative that you immediately turn off the furnace due to the fact that leaving it on poses a significant risk to your health. Turn off the power supply to maintain safety. Moreover, cut the gas supply as well for safety.

Troubleshoot the problem: 

Next, you should start troubleshooting the problems. There can be many issues, like gas solenoid, dirty furnace, etc. In these, you should take a few steps.

Replace the gas solenoid: 

Check for any issues with the gas solenoid and replace it if necessary. Sometimes, a gas valve solenoid might get stuck in high fire mode, which cannot be fixed in most cases. The correct action, then, is to simply replace it.

Clean the coil: 

Clean the coil if the pressure switch is malfunctioning. Check the inner and outer condensing coils for dirt and debris.

Fix the blower motor: 

Fixing the blower motor, filter, loose blower wheel, faulty switch, or insufficient combustion air supply may be necessary if the limit switch lockout or flame roll out switch is flipped.

Fix the switch: 

If there are errors with the signal indicating that the flame rollout switch has been tripped, then the problem can be easily fixed by resetting the flame rollout switch.

So at this point, it is necessary to locate the faulty blower. Then, check whether the problem is caused by a faulty blower motor, blocked pressure tubing, dirty filters, or a duct system with restrictions.

Turn on the power and gas: 

After you are done completing all the steps as mentioned above, you can turn on the gas supply and electric power. Then activate the heating system once more.

Ask help from professionals:

If the problem is still not solved, you should ask for help from a skilled person. If necessary, get professional help to solve the problem.

Final Thoughts 

When the yellow, red, or orange light on your furnace quickly blinks, it means that there is an issue inside the furnace that has to be fixed right away. Various situations might cause the lights in furnaces to flicker. Determine the reason why this is happening and troubleshoot appropriately.