What Does It Mean If Carrier Furnace Is Blinking Yellow Light?

When the carrier furnace is blinking yellow light then it’s sending you a signal that it has run into a problem. Maybe the carrier furnace is locked out, or one of the parts isn’t functioning normally. Perhaps a component is dead even.

However, what’s the specific problem when the light is yellow? What could be the underlying problem, and how can you resolve it? Let’s dive right in.

Should My Carrier Furnace light Be Blinking?

No, your Carrier furnace light shouldn’t be blinking when it’s running. As long as everything works smoothly, the unit will run without any blinking lights. However, anytime it begins to blink, there’s a problem.

The reason it blinks is to alert you about the underlying issue. It helps to swing in swiftly to troubleshoot and ideally fix the issue before it creates a bigger risk. Although codes 31,33 and 13 are the most common problems, others like low pressure switch fault, reversed line voltage polarity etc. The low pressure switch problem can be rectified by cleaning the condenser coils.

What Does a Yellow blinking Light on a Carrier Furnace Mean?

The yellow blinking light indicates that the furnace is stuck in high-fire mode. High-fire mode is a setting on the Carrier furnace in which the heater generates a lot of heat over a short period to “jumpstart” the heating process or heat a very cold house faster.

This is particularly necessary when the temperatures in your home are too low at the time the furnace kicks on. Engaging high-fire for a short period allows the carrier furnace to raise indoor temperatures significantly over a short period before it goes back to normal function.

High fire mode is usually 100% on most furnaces, though a few units can operate at up to 130% during high-fire. The bottom line is that it allows the furnace to raise indoor temperatures sharply over a short time, such as over a minute.

At the same time, some furnaces don’t have a high-fire mode. If this is the case, you must wait for indoor temperatures to rise gradually. Fortunately, all Carrier models have this mode.

As you can tell, though, high-mode isn’t entirely safe for livability and furnace health, especially over long periods. Running the furnace at 100% capacity for an entire hour, for instance, would quickly result in overheating, affecting both you and the furnace.

So, imagine if the furnace accidentally gets stuck in high-fire mode! It can be a terrifying situation.

The flashing yellow light is a safety mechanism designed to alert you that the furnace is stuck in high-fire. Four yellow light flashes on your York furnace means the heating system maybe restricted. When you see this error code, the air flow won’t operate as it should.

Reasons the Light on your Carrier Furnace is Blinking

The furnace can get stuck in the high-fire mode for several reasons. However, the leading cause is a defective gas valve solenoid.

The gas valve solenoid helps control gas flow by using a plunger to open or close the valve, allowing the gas to pass or seal off the passage without leaks. They are primarily incorporated into gas heating systems for increased safety and efficiency. The control board regulates the amount of voltage that reaches every part. There maybe a problem with the control board if you don’t hear a clicking noise when the unit is turned on. The average cost of replacing a control board is between $300 to $600. The replacement of control board is complex and requires a technician.

However, the gas valve solenoid can fail, thus refusing to open or close. If it refuses to close when the furnace is in high-fire, you’re in trouble. The blinking yellow light flashes to alert you to take action.

What to Do if Your Carrier Furnace is Blinking?

Unfortunately, a gas valve solenoid stuck in high fire mode cannot be repaired. Instead, you need to replace it. More importantly, this isn’t a DIY job. Instead, you need to find a licensed HVAC technician to help out especially when there is a broken internal component and the furnace is not producing heat or producing strange noises.

Carrier Furnace Error Codes (Others)

Carrier furnaces have many other error codes beyond the flashing yellow light. Some of these carrier furnace error codes include carrier error code 1-2 signalling that the blower is ON after the power-up and carrier error code 1-4, a sign of a secondary voltage fuse is open and there is low voltage. You ca rectify these situation by checking the secondary voltage wiring. Others are error codes 2-1, 1-3, 2-2,3-4 and 2-3.

However, the three most common error codes besides the blinking yellow light are 3-1, 1-3, and 3-3. So, what do they mean?

What does Carrier Furnace Code 31 Mean?

Error code 3-1 (or 31) typically signals a problem with the pressure switch. It can either be the draft safeguard, aux-limit switch, high pressure switch or the blocked vent switch. The pressure switch is a unique electrical relay switch located adjacent to the draft inducer fan. It tracks air pressure within the inducer fan box, which helps determine when it’s unsafe to run the furnace.

If the pressure isn’t low enough to flip the switch, it’s usually a sign that the inducer fan isn’t removing exhaust gases at the desired rate,defective inducer motor or capacitor, proper vent sizing or low inducer voltage. It’s dangerous to run the furnace with a defective pressure switch. So, the circuit will remain open, keeping the furnace shut.

Solution: To fix error 31 codes, check the inner and outer condensing coils are dirty and clean it, or if the high pressure switch is faulty and reset. If it’s still blinking error code 31, then the high pressure switch might be faulty. Replace it.

What does Carrier Furnace Code 13 Mean?

Error code 1-3 (or 13) signals a limit switch lockout (usually a manual reset switch lockout) or a flipped flame roll out switch . The limit switch is also a safety mechanism built onto most furnaces. Unlike the pressure switch, though, it sits beneath the ducts in the furnace cabinet. Its primary purpose of the flame roll out switch is to shut down the furnace when overheating. After cooling down, replace fuse link or the flame roll out switch.

You’re allowed to try to ignite the furnace again. However, if you try three times without success, the furnace will auto reset, a state in which the unit becomes unresponsive to external input until you reset it. The auto reset switch is a safety device that shuts off the gas valvein the presence of a flame rollout in the unit.

Solution: The only solution here is to fix the underlying issue. Why is your furnace overheating? Is it a problem with the gas flow? Is it a damaged limit switch?. These problems can be caused by defective blower motor, dirty filter, loose blower wheel faulty switch or inadequate combustion air supply After fixing the issue, reset the furnace and test to see if it works. Here too, we recommend professional advice as overheating is too risky to troubleshoot with DIY.

Carrier Furnace Code 33 Troubleshooting

Finally, Carrier furnace code 33 (or 3-3) errors signal that the flame rollout switch has tripped. The rollout switch keeps an eye on the flame to ensure that it’s burning healthily and within the combustion chamber. The switch flips to prevent overheating and potential fires if the flame rolls out beyond the combustion chamber.

The code is typically accompanied by a yellow flashing and essentially requires that you reset the carrier furnace.

Solution: Resetting the flame rollout switch isn’t too tricky. You can easily accomplish it without much knowledge of furnaces. However, the problem is the underlying issue. It’s counterproductive to reset the switch without addressing the cause. So, find out why your flame rolls out first and fix the problem. Check for defective blower motor, obstructed pressure tubing dirty filters or restricted duct system. Turn the power off, remove the blower access panel and disconnect the R thermostat lead. Although some carrier furnace repair issues can be troubleshoot you may need to engage a professional.

Carrier Furnace Blinking Yellow Light 3 Times

If your carrier furnace blinking yellow light 3 times, the furnace limit is in lockout mode or there is an issue with the pressure switch circuitry. A limit switch is responsible for turning on the furnace blower once the desired heat has been met inside the furnace. If the temperature is too high or the pressure too lowthe limit switch will close, instructing the furnace to shut down and enter lockout mode.

Here is what to do if your furnace is blinking 4 times

Carrier furnace code 34

The problem can be caused by the flame signal being lost and or not sensed during the trial for the ignition period, the blower will come on for 90 seconds recycle delay. check for the build up on the flame sensor, faulty hot surface ignitor, low inlet gas pressure, the manual valve is shut off.

Solution; you can clean the flame sensor by gently rubbing the metal rod with a very light grit sandpaper

Carrier AC Solid Yellow Light

If your carrier ac blinks a solid yellow light, it indicates that the furnace is stuck in high fire mode because of a malfunctioning gas valve solenoid. Usually, a high-fire mode should only operate for short periods of time to heat a freezing house faster. The continous blinking green light indicated the furnace is stuck in a low fire mode. A slowly flashing green light indicates the system is ON. When there is no the furnace light, then the unit is not recieving electrical power.

Carrier Furnace Blinking Red Light

When you see a blinking red light, the furnace is not receiving power to distribute hot air because the circuit box has tripped the furnace’s circuit breaker. In this case, the blower motor may be placed under too much stress due to blocked air vents around the house. This might be from moved furniture or people closing off the vent louvers. Look for a red or yellow button on the side of the blower motor and press the reset button down if it popped up.

Here is what to do if your furnace is blinking red light

How Do You Read a Carrier Furnace Error Code?

Carrier provides an elaborate owner’s manual to help users quickly decode the many error codes.

Generally, the blinking light will display a two-digit number. The first digit indicates the number of flashes by the yellow light, while the second one is the number of green light flashes. We recommend noting down the numbers and cross-referencing on your owner’s manual to find out the meaning.

How Do I Reset my Carrier Furnace code?

Resetting your furnace is considered the first line of action if the unit is acting up. The rebooting process allows the furnace to resolve possible issues internally before it comes on. The best part is that it’s a simple process that you can complete in four easy steps;

  1. Turn OFF the furnace (both power and gas)
  2. Change the furnace filter
  3. Make sure the pilot light is ON. If not, fix it first.
  4. Now turn the furnace back ON.

Error codes can provide invaluable pointers when troubleshooting a furnace. Sometimes the error code alone can lead you to the underlying issue. Therefore, if you see your furnace blinking yellow, you need to act fast before the issue worsens.