What causes a gas furnace not to ignite?
If your gas furnace initiates the start cycle but does not fire up, it’s likely because of a faulty, damaged, or dirty ignitor/sensor. This is a very common furnace problem—you can try to clean the sensor and replace the ignitor.
Why is my furnace igniter not working?
If your furnace won’t ignite, the source of the issue may be a broken flame sensor. The sensor is responsible for turning off the gas burners to avoid gas buildup. Once this component starts to malfunction, it may stop the burners from igniting altogether.
Why am I not getting power to my inducer motor?
If the inducer motor is only getting partial voltage (such as 70 or 80VAC), then it could be a loose connection. Another symptom of a loose wiring connection is an inducer fan that keeps turning on and off. Check all the connectors between the inducer fan motor and the furnace control board to make sure they are tight.
Can you run a furnace without an inducer motor?
Because the inducer motor helps your furnace run safely, the furnace will usually shut off if the motor won’t turn on. However, a bad inducer motor isn’t the only reason a furnace would shut off. A blocked gas vent flue or faulty pressure switch can have the same effect.
Where is the ignition sensor?
It’s located on the burner assembly and is just a thin metallic rod. It’s usually bent, and it sits just in front of the pilot flame inside the furnace.
Can the flame sensor cause no start?
Finally, flame sensor problems are a common reason behind a furnace not igniting. The flame sensor is the part of the furnace that actually ignites the flame and ensures that the flame stays lit. However, particle buildup on the flame sensor is common and often prevents the sensor from working properly.
Can hear your furnace click on but it does not fire up?
You Have a Faulty Ignition Sensor (Pilot Light)
The pilot light or ignition sensor is usually the most common issue when your furnace will not ignite. This is typically the problem if you can hear your furnace click on but it does not fire up.
How do you know if your igniter is bad?
Your furnace won’t run: The most obvious sign that your ignitor is bad is that it won’t ignite, and this generally manifests itself in your furnace failing to run when you activate it. One word of caution, though: this can also be caused by other issues, some of which are electrical.
Where is the ignition sensor on my furnace?
Quote from the video:
Quote from Youtube video: So the right side of the furnace.
How do you bypass an inducer motor?
Quote from the video:
Quote from Youtube video: So this is the wrong way to bypass a pressure switch. The right way is to have the inducer motor turn on first and then bypass the pressure switch.
How do I test my inducer motor?
Quote from the video:
Quote from Youtube video: You turn your button to heat you turn the temperature. Up. If at the control board you have 24 volts off from the W to the c-terminal. This is the next thing that gets called alright.
Should inducer motor spin freely?
Quote from the video:
Quote from Youtube video: So if your inducer motor is spinning freely the cooling blade or the shaft or whatever fan blades that you're spinning if they spin free then you know that the inducer motor is not stuck.
Is flame sensor same as Ignitor?
A flame sensor is a crucial safety component on your gas heating system. During the ignition cycle, your gas furnace goes through a process where a spark or a hot surface ignitor will actually ignite the gas. As the gas is ignited, the flame sensor creates a current of electricity.
Is the flame sensor the same as the igniter?
The flame sensor is able to detect the heat caused by combustion. When it does, it sends the signal to stop powering the hot surface igniter. If, on the other hand, a certain period of time elapses in which the flame sensor cannot detect a flame, it will automatically shut off the gas valve.
How do I know if my furnace flame sensor is bad?
6 Signs of a Malfunctioning Gas Furnace Flame Sensor
- Yellow Burner Flames. Open up or glance through the peephole of your gas furnace to see the color of the flames firing up in the burner. …
- Rusted Flue Lines. …
- High Utility Bills. …
- Water Leaks. …
- Old Age. …
- Constant Thermostat Adjustments.
What will a bad flame sensor do?
Good flame sensor: A properly functioning flame sensor will shut down the gas valve when it does not sense a flame when the furnace should be firing. Bad flame sensor: When the furnace has fired and is burning hot, a bad flame sensor won’t sense the heat and will shut down the furnace.
Can I bypass flame sensor?
Yes. You can bypass the flame sensor. However, if you do so, you can’t manually light your furnace, and you’ve got to have proper bypassing safety measures in place. But it’s advisable not to bypass the flame sensor.
Can a new flame sensor go bad?
It’s possible for a flame sensor to go bad; but more often than not, it is not broken, just dirty from carbon buildup. Because a flame sensor has a very low tolerance for variations in the reading it takes, the slightest coating of carbon can cause it to misread and shut down.
