Start by turning off the power supply to the furnace. Turn off the fuel supply for gas and oil furnaces. Remove the blower compartment access cover. Locate the reset button and press it. Put the cover back and switch the power supply to the furnace back on.
A simple procedure! However, this article explains what you need to troubleshoot before resetting the furnace. We then discuss the various steps you should take as you reset your carrier furnace.
Understanding Your Carrier Furnace
All carrier furnaces have a reset button. The function of the reset button is to shut the furnace unit off safely when a problem is detected. All operations stop, and the furnace goes into lockout mode.
All carrier furnace models show the lockout mode as error codes 31 and 13. If the reset button keeps flipping, your furnace is overheating.
The following are the reasons for the furnace reset button tripping.
- If the gas valves are closed or blocked. You can open the gas valves to sort out this problem.
- The flame sensor is coated with dirt or debris. Regularly wipe the flame sensor rod.
- A dirty air filter. Clean or change the air filter regularly.
- If the furnace tank does not have fuel. Request for a refill.
- The furnace is not receiving enough airflow. Keep the air vents open and clean the air filters.
- Malfunctioning motor drawing too much current.
However, overheating might not be the only reason why your carrier furnace not staying on.
Troubleshooting Steps Before Resetting
You should troubleshoot the most basic issues before hitting that reset button on your carrier furnace. Check if there is power, if the power switch is on, and if you’ve set the furnace to “heat.”
A few factors that you should troubleshoot before resetting the furnace.
- Thermostat: Is the thermostat getting power? Some thermostats use batteries. You should check to see if the batteries are dead. Ensure that the thermostat is set to “heat.”
- Temperature setting (set point): Adjust the temperature on the thermostat to be higher than the room temperature. The furnace will turn on and continue running at higher temperatures until the room temperature matches the set point.
- Circuit breaker/ fuse box: Confirm that the circuit breaker hasn’t tripped and the furnace is getting power.
- Gas supply: Ensure the gas supply is off if using a gas furnace. There are several reasons why your carrier furnace is not getting gas. Confirm that the handle on the gas cut-off valve is parallel to the gas line. However, do not touch any switches if you smell a gas leak. Proceed to call the gas company and wait for them outdoors.
If you’ve checked all the above factors and the furnace is still not working, proceed to reset it.
We give you a simple procedure to follow if this is your first time resetting a carrier furnace.
Shutting Off Power to the Furnace
The first thing to do is to locate the power switch on the carrier furnace. Check the user’s manual if you don’t know where your furnace’s power switch is.
Push the switch button off, and after a few minutes, push it on. You can push the reset button at least three times at 30-minute intervals.
Proceed to the next step if your furnace is not responding. But before doing that, ensure the following.
- If using an electric furnace, ensure the power switch button is off. Turn off the main power supply to the furnace.
- The pilot light for the gas furnace and the power supply are off.
- Turn off the fuel supply for gas and oil furnaces.
Locating and Accessing the Reset Button
Locate the reset button, most of them are red or yellow. The reset button for all carrier furnace models is inside the blower unit. You can also use the owner’s manual to locate the position of the reset button for your furnace.
You have to push the reset button to restart the furnace manually.
Confirm that the furnace is off. Use a screwdriver to open the metal compartment housing the blower unit where the reset button is. Press the reset button.
Put the cover back on.
Resetting a Carrier Furnace with a Control Board
The control board of your carrier furnace has all the necessary components to run. There are wires from the control board to the thermostat, ignitor, gas valves, and blower. A diagnostic light on the control board tells you when there is a problem.
A defective control board might be one of the reasons your carrier furnace is not blowing hot air.
However, you can use the control board to reset your carrier furnace.
Check the current Status
Start by checking the diagnostic light for the control board. That is the current status of the control board.
Check the error code and take action. For example, if the error code indicates a dirty air filter, replace it.
Switch off power
Alt: A Circuit Breaker (image on Pixabay).
After sorting the error code, switch off the furnace power. You can switch off using the toggle switch or a circuit breaker.
The diagnostic light should be off now, an indicator that no power is getting to the furnace.
Switch on the furnace
Wait for a few seconds and proceed to switch on your furnace. The few seconds that your furnace is off should be enough time for the control board to shut down and clear the earlier detected errors.
Carefully observe the whole process. The furnace should go through the entire process. But if it gets stuck, the furnace still has a problem.
If the furnace shuts down without completing the process and locks out, you must call an HVAC technician.
Resetting a Carrier Furnace with a Flame Sensor
Carrier gas furnaces have a flame sensor (furnace ignition sensor). The flame sensor ensures you can only open your furnace when a flame is present. If the sensor detects no flame, it signals the furnace control board to shut off the gas valve and the burners.
Follow the process below to reset a carrier furnace.
- Turn off the gas. Shut off the furnace’s electric power. Wait for a few minutes before proceeding to the next step.
- Locate the flame sensor at the back of the unit. It’s a rod-shaped device. Remove the access cover.
- Disconnect the wiring that leads to the flame sensor after loosening the screws. Remove the flame sensor from the bracket.
- Gently scrub the soot on the flame sensor using a lit-grit sandpaper or an emery paper. Use a lint cloth to wipe off all the residue.
- Reconnect the wiring to the flame sensor and tighten the screws. Confirm that the sensor is secure before attaching the furnace access cover back.
- Turn the furnace power back on.
The video below shows how to handle the flame sensor Furnace Not Working – Troubleshooting the Flame Sensor.
Suppose you’ve reset the carrier furnace, and it’s not igniting. Check the other reasons why the carrier furnace is not igniting.
Reconnecting Power to the Furnace
Once you push the reset button, the next step is to switch the power back on.
If, even after troubleshooting why your carrier furnace is not turning on and resetting it, the furnace still doesn’t work, contact an HVAC technician. Your furnace might have a safety issue that requires repair.
Testing the Furnace Operation
Alt: Smart Thermostat (image from Carrier).
If your furnace is now running, you might still need to test if it is now okay. You don’t want it failing at night.
The best way is to perform a temperature ramp. Adjust the furnace thermostat to a higher temperature than the one in the room. After 30 minutes, you should feel the temperature in the room become warmer.
If the temperature in the room becomes warmer, the furnace is working again. However, if the room temperature remains the same or becomes cooler, the furnace is not working.
You have no choice but to call an HVAC technician to inspect the furnace.
Common Error Codes and Solutions
Various brands will have different error codes for their furnaces. The table below highlights standard error codes for the carrier furnaces and their solutions.
| Error Code | Error Code Meaning | Solution |
| Rapid LED flashing | Line voltage polarity is reversed. | Refer to the twinning kit instructions if twinned. |
| 1-1 | There is no previous code. | By interrupting the power. |
| 1-2 | After power up, the blower is on. | Let the blower run for 90 seconds. |
| 1-3 | Limit or flame roll-out switch lockout: | The control will reset after three hours. Replace the fuse link or reset the switch. |
| 1-4 | Ignition lockout. | Control will auto reset after 3 hours. |
| 2-1 | Gas heating lockout. | Check for a defective control or a gas valve wired badly. |
| 2-2 | Abnormal flame proving signal. | Check for a gas valve stuck open or a leaking one. |
| 2-3 | Pressure switch didn’t open. | A pressure switch is stuck open, or there is an obstruction in the pressure tubing. |
| 2-4 | Secondary voltage fuse is open. | Confirm if the secondary voltage wiring has suffered a short circuit. |
| 3-1 | Draft safeguard, pressure, aux limit switch reopened or didn’t close (downflow only). | It is probably a defective blower motor, restricted vent, low inducer voltage, or obstructed pressure tubing. |
| 3-3 | Limit or flame roll-out switch is open. | You’ll have to do a manual reset. |
| 3-4 | Ignition proving error. | Check for a defective/turned-off gas valve, low inlet gas pressure, or ungrounded flame sensor. |
Raoul Lobo is a seasoned expert in the realm of home appliances and environmental comfort. As a prominent author at TemperatureMaster.com, Raoul’s passion and expertise shine through in his insightful articles and guides. With years of hands-on experience, he has become a trusted source for readers seeking advice on pools, washers, dryers, and a wide range of other appliances.