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Furnace Flame Goes Out When Blower Comes On [Answered]

Your furnaces must be serviced regularly to ensure good operation. An efficient furnace will keep your house warm even when it’s below zero outside. Those who have awoken to a frigid house owing to a broken furnace realize its importance. 

Why does your furnace flame go out when the blower comes on?

Your furnace’s blower may occasionally start and stop without warning. This can occur as a result of clogged or malfunctioning sensors. Faulty ignition boards are also another reason behind this. Overheating can surely cause this as well. Faulty wiring and pressure switch are equally responsible too. But all of this can be fixed. 

Just a little teaser there. But we’ve broken the process down into steps for your convenience.

So, what are you still waiting for? Come on, let’s go for it!

Why Furnace Flame Go Out When Blower Comes On? [With Solution]

Before going into the reasons, remember that furnace overheating can be a serious cause. You should be concerned about that before starting to fix the issues. If the furnace is heating up really quickly, quickly call an expert to fix it. 

Let’s get into the topic!

Reason-1: Faulty Switch for Flaming Rollouts

There’s a chance your furnace’s flame rollout switch is broken. You’ll know it’s this by looking at how long it lasts. It runs for a short period of time in the majority of cases. 

It happens before shutting off when the blower kicks on. The flame rollout switch keeps tabs on the overall heat output. 

Solution: Reset the Flame Rollout Switch

Turn off the furnace’s circuit breaker before touching it. To avoid a fire or electric shock, turn off the gas while you reset the switch.

Inspect your furnace’s burner access panel. The gas burner component is visible on the furnace’s top. The furnace must be completely cool before you can start fixing it. 

The reset button for the flame rollout is usually red. Reinitialize the electricity and gas when you’re done. If the first try fails, turn off the electricity and gas, try again. 

When everything else fails, this means the reset button is broken. 

Reason-2: Flare Sensors

Flare sensors and flame rollout switches are quite similar. The flame sensor’s primary responsibility is to monitor a gas burner. But it doesn’t observe the heat generated around them. 

To eliminate the furnace’s flame sensor, you’ve to check it. If it begins to heat up, immediately turn it off. When this occurs, the control board shuts off the gas valve’s power. It also ends the heating cycle.

Solution: Clean the Flame Sensor

Cleaning the flame sensor usually fixes the problem. Use a gentle abrasive pad to remove any buildup from the flame sensor. There are some other effective ways of cleaning a furnace flame sensor.

It should be done without harming or damaging the sensor. However, if the issue persists, a new flame sensor should be installed.

Reason-3: Damaged Control Board

You don’t want anything to go wrong with this component. Because it controls the flow of power to the furnace’s various components.

The control board needs to be examined thoroughly to know if it’s damaged. 

Solution: Replace the Control Board

The board may fail if it stops working. If this happens, it fails to supply enough voltage to the appropriate components. 

Replacing it can solve the problem. Because repairing the control board can’t fix them properly. That’s why replacing is the best option for a damaged control board. Take help from a professional to replace it. 

Reason-4: Damaged Pressure Switch

The pressure switch in your furnace could be faulty. Even if it’s just on for a short time before shutting down, this can happen.

The ignition process can be paused or stopped if the switch is faulty. It’s not uncommon for heaters to stop working properly. Furthermore, cold air coming out of the electric heater can be a serious issue. 

Solution: Replace the Pressure Switch

Switch off the furnace’s power by flipping the breaker first. The combustion chamber cover should be removed. Disconnect the cables from the pressure switch’s front panel then. 

Remove the vacuum tubes from the unit’s side. Grab hold of the pressure switch and lift it out now. Remove screws holding it in place. 

It’s time to replace the old switch on the motor. You can do it either by sliding it on and screwing it down. Connect the new pressure switch’s cables and vacuum tubes afterward.

Replace the combustion chamber panel and the thermostat.

Reason-5: Faulty Draft Inducer Motor

The pressure switch will not close if the draft inducer motor is faulty. The ignition process will be disrupted if the pressure switch fails to close properly. 

As a result, cold air will enter your house.

The draft inducer fan motor draws air into the burner before it is exhausted. It closes when enough air enters the burner. 

Signaling the circuit board means that sufficient air is present.

Solution: Fix or Replace the Inducer Motor

Draft inducer motors are notoriously difficult to repair correctly. The usage of duct booster fans helps to keep your home’s air clean. Though you must wire your duct booster fan to the blower

Now, you might want to fix the inducer motor yourself. But it’s a really hard and time-consuming task. Hiring a professional is almost always preferable.

You can also choose to replace the motor. It’ll cost you but it’s always the safest option. 

Now, we wanted to suggest you a few of the best inducer fan motors-

Product 1
Product 2

Check them out!

Reason-6: Problems with Airflow

There’s a possibility that your furnace is experiencing issues with ventilation. If your furnace isn’t getting enough air, it will cycle on and off. 

It usually happens when the fan starts. The burner in your furnace must have sufficient airflow to remain lit. 

The thermostat’s limit may not be reached because of insufficient airflow.

Solution: Turn On the Ceiling Fan 

Try running the ceiling fan and it’ll improve the airflow. Another option is to use a standing fan or a table fan. 

All you’ve to do is to add some air circulation. You can also place it somewhere cool if it’s a portable furnace.

If your furnace uses outside air, ensure that nothing is blocking the air entry. It’s more likely in the winter that an accumulation of ice will obstruct proper airflow.

If doing all these didn’t solve your problem, you’re out of luck. Don’t forget to claim the warranty if you have. You can also call some experts to provide detailed insight.


Question: Can you put a flame sensor through its paces?

Answer: To measure the flame signal, connect your meter in series with the flame sensor’s wire. Your flame sensor is unclean if you get a reading of less than 5 uA.

Question: Are thermocouples and flame sensors the same thing?

Answer: “Flame sensor” and “Thermocouple,” are words commonly used interchangeably. Although they do the same general job, they are not the same. A flame sensor is built into an electronic furnace controller. With a pilot light, thermocouples are employed in standing pilot furnaces.

Question: For an effective flame sensor, what voltage level should it read?

Answer: The furnace’s control board sends a low current voltage to the flame sensor. The voltage usually ranges between 40 and 80 volts AC.


To summarize, this is everything about furnace flame goes out when blower comes on. We sincerely hope you liked reading with us. And we were able to satisfy your curiosity. 

Lastly, good luck solving the problem!