Dirty flame sensor If this sensor is dirty, the dirt can cause the sensor to operate intermittently. When this happens, your furnace will most likely light, but because the sensor can't properly detect if a flame is present. The sensor may signal the ignition cycle to end, which your furnace won't stay lit.
Do flame sensors wear out? Flame sensors wear over time. However, often the problem is a dirty sensor, rather than a broken one. Since these sensors are designed to have a low tolerance for reading variations, they might misread from the slightest carbon coating.
If the flame sensor is clean but the burners still shut off around 6 seconds after ignition, this may be the result of a faulty ignition control. A common cause of a faulty ignition control which fails to sense flame is water damage.
There are many possible reasons why the burner will not stay lit - the gas jet may be blocked, the valve may be set too low, the air flow may be restricted, there may be an issue with the pilot light, and so on.
Are your furnace burners only coming on for a few seconds? This is the most common furnace problem which also happens to be the easiest thing to fix! Every furnace is different but almost all of them have a flame sensor. If your flame sensor is dirty or covered in a layer of dust, it will shut the burners off after lig.
Any issues with the gas valve that supplies that gas to the flame, whether it be dirty or malfunctioning, can result in that flame going out. It's also possible that your gas supply has run low or out entirely, which will also cause the flame to blow out.
Faulty flame sensor
This is a common cause of burners that won't stay on. The flame sensor is a safety precaution in a gas furnace that tests that the gas coming from the burners has ignited.
While the most common causes of log burners going out are insufficient oxygen, fuel or heat, stoves also rely on a properly functioning chimney. The purpose of this is to draw out exhaust fumes that could suffocate your fire.
It may be that it's dirty and needs cleaning. It can easily be cleaned off with fine grain sandpaper. A dirty pilot tube can also prevent the pilot from staying lit. If the pilot tube is dirty, let the furnace cool down and turn off the gas.
There is a work-around to waiting. If there is no safety risk (like a gas leak), a furnace can be reset to bypass this wait. Turn off the furnace's power switch and wait 10 seconds before turning it back on.
While most furnaces last for 10 to 20 years, flame sensors have a much shorter lifespan of about five years. Usually, when a flame sensor goes bad, the best route is to replace it outright.
Short cycling is a common sign of a bad flame sensor. The sensor thinks that there isn't a flame, so it shuts off the gas as a safety mechanism.
If it's still not operating properly, you should call for furnace repair. How Often does it need cleaned? Most experts recommend cleaning the flame sensor once a year.
If your gas fireplace pilot light keeps going out, you may have a problem with faulty pilot controls. The pilot control failing due to age or a mechanical issue can cause your pilot light to keep going out and prevent it from being relit.
Most furnace flame sensors cost less than $20, but if you opt to have a professional HVAC technician make the repair, you can expect to pay between $75 and $250. Need help replacing your flame sensor?
If your burner lights for a short time but then goes out, you may have a blockage in the gas valve. The gas line is what provides fuel to the burner to keep it lit. A complete blockage often prevents the burner from lighting at all.
The most like culprits are likely tied to some kind of problem with your setup. Anything from issues with your pilot light, clogged ports on burners, damage to heating components, and thermocouple/thermopile malfunctions can be to blame.
A furnace cycling on and off repeatedly can be caused by various reasons, from dirty filters and obstructions in ducts and registers to incorrect thermostat settings and faulty limit switches. By following the steps above, you can help prevent your furnace from cycling too frequently and save energy costs.
The flame will go out if you release the knob before it is hot. The thermocouple can become dirty and caked with grit, preventing it from heating up and detecting that the pilot is lit. As a result, the pilot will always go out after you release the reset button.
A furnace flame sensor can fail due to several reasons, including: Dirt buildup that prevents it from detecting the flame. Corrosion from moisture or improper maintenance. Incorrect positioning within the furnace.
Dirty flame sensor
If this sensor is dirty, the dirt can cause the sensor to operate intermittently. When this happens, your furnace will most likely light, but because the sensor can't properly detect if a flame is present. The sensor may signal the ignition cycle to end, which your furnace won't stay lit.
The most common cause of this is dirty or blocked burners, which is the part that you can easily take off to clean.