Table of Contents
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.
How do I know if my flame sensor is bad?
First, check for your gas burners to light up and then go out after a few seconds. This is the most common sign of a sensor issue. Second, if you can actual see soot covering the tip of the sensor, it’s time for a cleaning. If you look at the tip and it’s black, it’s time for service.
How does a flame sensor work?
A furnace flame sensor works by detecting the presence of a flame within the furnace. As the gas valve opens to begin the combustion process, the current is sent out from the sensor in order to detect the presence of heat from a flame.
Will a furnace run without a flame sensor?
The flame sensor is an important safety feature inside a furnace. Without the flame sensor, if the pilot light goes out but the gas valve remains open, the gas will not burn and will seep out of the furnace. This is a dangerous situation that can result in gas poisoning or even an explosion.
What will a bad flame sensor do?
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.
How much should it cost to replace a flame sensor?
Flame Sensor It stops your furnace from letting off large amounts of natural gas if it’s not working properly. If the sensor is bad, it won’t be able to sense heat and will turn the furnace off. The average cost to repair or replace a flame sensor is between $75–$200.
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.
What should a flame sensor read?
When the burners ignite you should read between . 5 and 10 micro-amps depending of the furnace. Readings between 2 – 6 are most common.
How does a flame sensor work on a gas dryer?
Located on the burner funnel, the flame sensor detects the igniter temperature. When the igniter is hot enough to light the gas burner, the flame sensor shuts off the igniter, the coils open the gas valves, and the burner ignites. Replace a failed flame sensor with the manufacturer-approved dryer part.
Can you bypass the flame sensor?
Well, while disappointing to some readers, here is the answer: No, bypassing the flame sensor isn’t a solution. You won’t find steps to bypass the flame sensor anywhere. Attempting to bypass the flame sensor is not a good idea, even if it were possible. The flame sensor is an important safety feature on your furnace.
How long do flame sensors last?
Flame sensor lifespan If you’ve just replaced the sensor or had a new furnace installed, you can expect the flame sensor to last for about five years. The average lifespan of a furnace is 15 to 30 years, so you can anticipate a flame sensor replacement once or twice over the course of your homeownership.
Is there a way to bypass flame sensor?
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.
Why does my gas furnace keep shutting off?
If your furnace keeps shutting off, it could be due to low airflow. There are several indirect issues that cause low airflow. Dirty Air Filters. If you don’t change your air filters often enough, the filters will become dirty and clogged, which means the heat exchanger retains heat and eventually causes it to overheat.
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.
What causes a dirty flame sensor?
It is a sensitive sensor so any type of dust or carbon buildup could cause it to malfunction. Most people have their furnaces in a basement or laundry area where there is excess dust in the air. This dust could stick to the sensor making it dirty and causing your furnace to shut down.
What makes flame sensors dirty?
The most common is that it is dirty. Because burning fuel of any kind produces trace amounts of moisture, over prolonged exposure to these conditions, metal will rust. Since your sensor is made of metal, rust can build up, preventing proper sensing of the flame.
