How to Reset a Furnace Control Board in Four Steps

Knowing how to reset a furnace control board can go a long way in helping you protect your furnace from developing serious damage.

There are several issues that could call for the need for a furnace reset. For instance, your furnace could become too hot. Sometimes, the reset could be down to a flame sensor problem or closed gas valve. Whatever the case, it is essential to know how to reset your furnace control board.

Read on to learn how to reset your furnace and why turning to heating installation experts in Vero Beach, FL, is essential.

What Is a Furnace Lockout?

Using your furnace in unsafe conditions will result in the complete shutdown of your furnace, or what is known as a furnace lockout.

Homeowners can experience either a soft or hard lockout. A soft lockout happens when one of your furnace’s sensors detects an issue. During the lockout, your furnace will sit idle until the soft lockout period ends.

For instance, if your furnace’s high limit or flame sensor trips, it will go into soft lockout for one to three hours. Afterward, it will automatically try to start up.

Hard lockouts occur after your furnace experiences multiple repeated soft lockouts and often indicate the presence of a severe issue. In most cases, your furnace will go into a hard lockout if it goes into soft lockouts more than three times.

During hard lockouts, your furnace will not restart until your reset the control board.

How to Reset Your Furnace Control Board

While learning how to reset your furnace control board is relatively straightforward, it is vital to determine why your furnace locked out in the first place and address the issue. Doing so will go a long way in preventing your furnace from locking out again.

Also, the steps you take when resetting a gas furnace will differ from those you’ll follow when resetting an oil furnace.

Here are the steps to take when resetting your gas furnace.

1. Check Your Furnace’s Diagnostic Light

The first thing you should do when resetting your furnace is to check your control board’s diagnostic light. The light will indicate your furnace’s current status.

Looking at the furnace's error code chart will help you determine your furnace's status.

For instance, if the furnace is not receiving a signal from the flame sensor, the light will flash in a specific pattern that will indicate that.

Once you determine the issue, take action to remedy it before proceeding to the next step. In some cases, the problem could be down to a dirty air filter. As such, changing the filter whenever your furnace develops an issue could remedy the situation.

2. Turn the Power Off

After checking your furnace’s diagnostic light and correcting the issue, turn your furnace’s power off. To do so, look for the toggle switch and flip it to turn your furnace off. The toggle switch will resemble a standard light switch.

If you cannot find the toggle switch or your furnace doesn’t have one, look for the circuit breaker that supplies your furnace with power and switch it off.

Check the diagnostic light once more and make sure it stays off.

3. Switch on Your Furnace

Once you switch off your furnace, wait for a few seconds, then turn it back on. Doing so gives your furnace's control board the time it needs to shut down and clear the errors the sensors detected.

Remember to observe your furnace as it starts up.

Is your furnace going through its entire operation sequence, or is it getting stuck somewhere in the middle of the process? If, while starting up, the furnace is getting stuck on one of the steps, it still has an issue.

Sometimes, your furnace could start up completely, only to shut down and lock out after running for a while.

If this is the case, you will need professional assistance.

4. Relight Your Furnace’s Pilot Light

Depending on your furnace’s model, you might need to relight the pilot gas light for the furnace to fire up. Doing so is especially common in older furnaces.

The pilot light provides your furnace's burners with an ignition source. When the light is out, you will need to relight it before switching your furnace back on.

However, if you have a newer furnace, it will probably have a hot surface igniter. If this is the case, then you can skip this step.

How to Reset the Control Board of an Oil Furnace

As mentioned earlier, the steps you take when learning how to reset a furnace control board will depend on the type of furnace you have. For instance, if you have an oil furnace, you will find the furnace reset button somewhere in the blower compartment.

Remember not to press the reset button multiple times to avoid creating a fire hazard.

Like gas furnaces, you will need the services of a professional HVAC technician if your oil furnace constantly needs resetting.

Professional Furnace Repair Services in Vero Beach, FL

An optimally functioning furnace is essential, even in a tropical city like Vero Beach, FL. While furnaces are usually reliable, they are also delicate systems that can develop issues that affect their operation. Fortunately, learning how to perform a furnace reset can help limit the frustrations of a locked-out unit.

Though furnace resets are easy to do, it is always best to let a licensed technician investigate your unit to ensure that your furnace does not have a severe issue.

At Bates Air & Heat LLC, we dedicate our specialized expertise and vast experience to providing prompt and reliable furnace repair services. No matter the issue, we can quickly address it without compromising quality.

If need be, we can even replace your furnace and AC at the same time.



While knowing how to reset your furnace control board is vital, reaching out to our technicians will allow you to enjoy comprehensive solutions. Call Bates Air & Heat LLC at 772-773-6926 to schedule your service today.