If your home has a furnace, it will likely run into problems at some point or another. That's why it helps to know about some potential problems you can run into and how they are fixed.
Dirty Flame Sensor
Your furnace has a stainless steel rod located behind the burner called the flame sensor, and a common problem with it is that it gets dirty. A good indication that you have a dirty flame sensor is if the furnace turns on for a few seconds before shutting off again. This is because the sensor is not able to tell that the flame inside the furnace is turned on, and it shuts off the furnace as a safety precaution. If you're able to access the flame sensor, you can clean it with something as simple as a kitchen scrub pad.
Dirty Furnace Filter
Your air filter is located on the return air duct before the air enters the furnace, and it can get quite dirty over time. Make it a regular habit to change the filters by having a bunch on hand so that you can replace them every other month or so, depending on how much you use your HVAC system. One thing to be aware of with a furnace filter is that they are designed to go into the furnace in a certain direction. Look for the arrows that tell you which way the air is supposed to flow through the filter.
Damaged Inducer Motor
The inducer motor is supposed to be a little warm to the touch after it has been in use for a while, which is why it is a reason to be concerned if the motor is completely cold. This means that the motor is not getting the electricity it needs, either due to a wiring issue or the motor being dead. A heating repair technician can diagnose the part and determine if it needs to be replaced completely or rewired.
Damaged Blower Motor
You'll find the blower motor at the bottom of the furnace near where the air filter is. It's a small fan that can be freely spun by hand if it is working properly, but a blower motor that has seized up will be stuck. You may notice a problem with the blower motor due to getting very little air through your ductwork, or even smelling a burning smell when the furnace is running. The problem could be solved by simply fixing the capacitor on the part, or installing a whole new blower motor.