Table of Contents
Where is my furnace flame sensor?
The flame sensor on your furnace is an important but simple part. It will look like a thin metallic rod and is set in front of the pilot flame on the interior of your furnace. Both of these parts can be located inside of the burner assembly of your furnace which is typically in the bottom of your furnace.
How do I know if my furnace flame sensor is bad?
Signs of a bad flame sensor Furnace burners turn on but go out after a few seconds. Soot and other debris is covering the end of the sensor (cleaning the flame sensor may fix this issue rather than a flame sensor replacement) Tip of flame sensor is black. Porcelain/sensor casing is cracked.
How much does it cost to replace a furnace flame sensor?
You can expect to pay between $350 and $500 for a new flame sensor if you call a furnace repair company.
Do all furnaces have flame sensors?
Not all furnaces have a flame sensor, but if your furnace has one, it will be mounted close to the burner with the metal rod positioned in the flame. Flame sensors vary in size (2 to 4 inches) and shape (see examples below).
What happens when flame sensor goes bad?
What happens when a flame sensor goes bad? Without a flame sensor, your furnace will keep emitting gas even when there’s nothing to ignite it, resulting in hazardous gas buildup. If your flame sensor is dirty or faulty, it will automatically shut down the heating unit if it doesn’t detect a flame.
What causes a flame sensor to go bad?
What are causes of a dirty flame sensor? As with any piece of equipment a simple reason could be that dirty flame sensor just goes bad. However a more common reason is that it is just dirty. It is a sensitive sensor so any type of dust or carbon buildup could cause it to malfunction.
How do you trick a flame sensor?
Luckily, making such a check is very easy: Take a multimeter with microamps (µA) measuring system. Keep the furnace system turned on. Connect it to the wire that is leading to the gas valve. Connect the other side of the multimeter to the sensor terminal. Take the lead away from the flame sensor.
How do you bypass the flame sensor on a furnace?
Turn off electrical power to your furnace either at the furnace or at the electrical box. Close the gas valve. Remove the flame sensor.Cleaning the Flame Sensor Shut off power and gas to the furnace. Remove the sensor. Clean away soot and corrosion with a clean emery cloth. Reinstall the flame sensor. Restart the furnace.
What is a furnace flame sensor?
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.
Why is my furnace not blowing hot air?
First, check to make sure the thermostat is set correctly. You will want to make sure that the fan control is set to auto, and not ‘on’. If the thermostat appears set correctly, turn off your heater at the thermostat and check the filter. If the filter is dirty, replace it.
Why does my furnace keep starting and stopping?
The most common issues that can cause your furnace to stop and start again are: Restricted Airflow: Your furnace draws in air from your home and then cycles the warm air back into your home. If your intake vents and exhaust vents are blocked or airflow is restricted, then you could experience short cycling.
How long should a furnace ignitor last?
Don’t worry—an ignitor that goes bad is common for most furnaces. Fortunately, you can replace the ignitor without replacing the full furnace. Most ignitors last about seven years.
How many sensors does a furnace have?
To maintain a preset air temperature, an HVAC system will typically have one or more interior air temperature sensors, an ambient (outside) air temperature sensor, and possibly one or two solar load sensors.
Are flame sensors universal?
Universal flame sensors: You might not need an exact replacement part. Universal sensors are available too. They are available at Home Depot, Menards or other building supply store.
Can hear your furnace click on but it does not fire up?
The Pilot Light (Faulty Ignition Sensor) 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. If the sensor or ignitor is dirty, it will need to be cleaned.
How often does a flame sensor need to be replaced?
Note: According to HVAC.com, the expected lifespan of a flame sensor is about 5 years. Most furnaces last anywhere from 10 to 20 years. That means that you will have to replace a flame sensor 1x, 2x, or even 3x during a furnace’s lifespan.
