Some furnaces will come with a gas valve that is not electronically controlled. For instance if you read the value one at a time, you could use your sensor to figure out which direction a flame is in (at a short distance, depending on the sensor). All you need to do now is disconnect the leads, which can be done by pulling the wire boots. It includes an alarm system, a natural gas line, propane & a fire suppression system. You should be getting a low resistance reading on your multimeter. If you feel safer, you can also shut the power off on the furnace itself. Think of it as a chain reaction. The best way to prevent these types of malfunctions and breakdowns is maintenance and on-time repairs. Troubleshooting: . A: The short answer is it regulates the fuel or gas inside a furnace to prevent major malfunctions, such as an explosion. As with any major appliance, safety features are always important. The same is true with flame sensors. Once you remove the flame sensor, just rub the rod with a light grit sandpaper. Should I Open the Windows in Late Summer and Early Fall. As this gas lights, it is important that everything is working correctly to prevent an explosion or gas leak. If you cleaned your flame sensor but it’s still malfunctioning, you may need to replace it. Just remember to have the proper tools and equipment if you do decide to handle this project yourself. This will include the proper tools. Copyright Heating and Air Conditioning St. Louis by Galmiche & Sons - All rights reserved. However, if you always keep your flame sensor clean, it could just be that the sensor has gone bad. The same thing goes for a furnace. However, the most common issue is a dirty flame sensor. This article will answer three questions: 1. Flame sensing rods stick out into the flame and connect back to the furnace board. A burner with no flame may release gas into the air. You can keep your sensor clean by maintaining it on a regular basis. If your furnace uses an electronic controller, it’s got a flame sensor. It begins as the igniter or spark ignites the gas to create the flame. The good thing about this step is that it’s easy to do. The job of the flame sensor is to quickly confirm that there is actually a flame present when the gas valve is open so natural gas isn’t being dumped inside your home instead of being burned inside the furnace. Make sure that you also have extra paper towels on hand. As an Amazon Associate we earn from qualifying purchases. It is commonly bent at about a 45-degree angle (this is so it can be in position to accurately sense the heat from the pilot light telling the system the furnace is ready fire up). Therefore, any type of dust could affect its performance. A: The flame sensor can be easy to clean if you follow the steps carefully. This central controller operates the gas or fuel valves for releasing the combustible materials into the burning chamber of the furnace or boiler. How to Check the Flame Sensor. Some of which are so small and out of the way that you rarely notice them doing their job. One of those components is the flame sensor. It does not feel heat, it instead passes a small electrical current thru the fire itself, so it has to be in the flame. The flame sensor is able to detect the heat caused by combustion. However, if your furnace is poorly maintained, experiencing operational problems or reaching the end of its operating life, it can encounter some safety issues that can be of serious concern. What is a flame sensor and How does it work? So why is there a flame sensor in your furnace and how does it play such a crucial role in furnace safety? A furnace flame sensor works to regulate the flow of gas coming into your furnace and automatically shuts down the unit if the gas burners do not light as to prevent gas build-up or worse, gas poisoning or catastrophic explosion. A bad flame sensor. So, it is very important that your sensor is working correctly and not damaged or misreading the electrical feedback from your furnace. First find the flame sensor. HomeRepairGeek.com All rights reserved. It then monitors the flame until the furnace shut down. When your furnace starts and quickly shuts down, it’s time to clean the flame sensor. I can simplify this a bit for you. If it is cracked, you could be dealing with a broken flame sensor. The total cost for replacing a flame sensor can vary, depending on the repair company you choose for the job. Gently clean and rub the metal rod with the sandpaper. When your furnace is well-maintained and working properly, it doesn’t pose any safety risks to your home. We’ve established earlier that a flame sensor is a device used to detect fires in furnaces but it can be referred to as a piece of safety equipment as well, providing confirmation as to whether the furnace is … If flame sensor requires cleaning more often then once a year it should be replaced, or check for other problems like vent stack temperature, gas pressure, or primary air need to be adjusted. Burner surface to flame sensor is 4:1 ratio thus causing the AC current to change to DC current. The whole process is an ignition sequence. As the gas is ignited, the flame sensor generates a … As part of the furnace thermocouple, the flame sensor piece is what’s responsible for measuring heat coming from your lit pilot flame. Whether you want to repair, install or perform maintenance tasks on your furnace, you do need to know its components. A Flame Sensor is a device that can be used to detect presence of a fire source or any other bright light sources. The best long term solution to nuisance flame failures and dirty flame sensors is to find and remove contaminants from the combustion air supply. There are several different types of flame sensor - some will raise an alarm while others may activate a fire suppression system or … A flame sensor is an important safety element on your gas heating equipment. What you're hearing is pre-ignition, which occurs when there's a pocket of fuel/air mixture that's igniting ahead of the flame front from the spark plug. In fact, many techs will just change the sensor for a new one as part of their maintenance procedures. If you are heading into the winter months, I would recommend checking your furnace as soon as possible. Once you have the proper tools, you can start the cleaning process. Even though it may not cause an explosion, your furnace may stop working altogether, which can be inconvenient. It helps your furnace regulate the ignition sequence and prevent dangerous conditions. There are several different types of flame sensor - some will raise an alarm while others may activate a fire suppression system or deactivate a combustible fuel line. In a nutshell, the flame rectification system is an electrical process that causes a low level DC current to be conducted from the flame rod through the flame, and back to ground. It may seem like there are endless HVAC components to clean, replace, and worry about. To learn more or to schedule a maintenance check if you suspect a problem with your furnace, contact our St. Louis heating & air conditioning specialists at Galmiche & Sons today! There are several ways to implement a Flame Sensor but the module used in this project is an Infrared Radiation Sensitive Sensor. To learn more about how these parts keep your HVAC system functioning and your family safe, get in touch with the heating & air conditioning professionals at Galmiche & Sons in St. Louis today. If the furnace does light but shuts down immediately, this would indicate a flame sensor issue. A flame sensor is an important safety element on your gas heating equipment. Thankfully, there is an easy check that your service team can perform during your next HVAC system maintenance visit to determine if there are any issues with your flame sensor. During the ignition cycle, your gas furnace undergoes a process where either a hot surface ignitor or a spark actually ignites the gas. Still, these components need to work correctly in order to keep your HVAC running smoothly and your home comfortable year round. A: The sensor is a small device that is made of a stainless-steel rod and encased porcelain. This is what makes the flame sensor so important. The flame sensor in your photo uses the electrode in the flame vs. the frame of the furnace (which includes the root of the flame) and is connected to the mounting lug on the flame sensor (that's why there is a ceramic insulator in there). This should complete the process of cleaning the sensor. A small piece that communicates between your furnace’s ignition and control board, the flame sensor may appear unassuming but it is a crucial part of HVAC safety. People tend to use the terms “flame sensor” and “thermocouple” interchangeably. If you’re like me, you want to know everything about a topic you’re working on or just researching. Next, simply replace the flame sensor back in its place. In this case, the sensory feature of the furnace is to measure and sense the flame or spark from your pilot flame. The flame sensor is a safety feature that is designed to protect your family and your home from dangerous conditions that can arise after the gas is ignited. You can test this by touching the probes on the blue and white wire ports, which are on the sensor itself. Make sure that you also look at the porcelain on the sensor. Or it can simply wear out. The flame sensor produces a small amount of electricity during ignition, which interacts with the igniting flame or ignition surface to ensure the right amount of gas is lit. Would recommend it for any flame sensor type issues you are having. How the flame sensor works is by a small AC electrical charge going through the sensor and it uses the flame to carry the electrical power to ground. Home » Flame Sensor: A Crucial Part of a Furnace. The furnace will come with a control board that measures this reading once the ignition process starts. The flame sensor, it turns out, is a key part of a safe ignition sequence. A flame sensor detects heat coming from the burners. Dryer won’t heat? If the control board does not read the correct level of electrical current, the furnace will cut off the fuel intake to prevent an explosion or fire. When the sensor becomes blocked with debris, the heater will not work properly. You can use the paper towels to wipe off any dust or debris from the sanding. However, over time, the constant heat/cool cycles cause the igniter to crack and fail. One key aspect of HVAC safety and maintenance is regular cleaning, with special attention to safety components like sensors and other diagnostics. 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. Energy Efficient Heating: 5 Simple Tips to Help You Heat Your Home More Efficiently. There’s not much to this component – you’ll see a thin, rounded rod about the diameter of a coat hanger near your row of burners. One such safety hazard is a flame rollout. The purpose of the flame sensor is to confirm to the system that whenever the gas valve is open, a … A: Now we’re getting to the good stuff. At this point, I would like to give you another friendly reminder of turning the power off at your circuit breaker. If it doesn’t detect a flame when the gas is on, it automatically shuts everything down to make sure you’re safe. You may also find the white porcelain of the flame sensor cracked or broken. If the flame sensor fails, the ignitor may not go off and the gas flow will not start. You can check this by referring to the manufacturer’s instructions. In this case, you can try to replace the flame sensor yourself. The sensor is usually located on left side but on some furnaces it may be on the right side. In truth, while they basically perform the same job, they’re not the same thing. It’s not much more than a thin, usually bent, metallic rod that sits in front of the flame stream inside the furnace. The flash code descriptions are: 5 flash (PCBBF134/136/140), flame sensed without gas valve and 1 flash (PCBBF139), flame sensed when no flame should be present and E4 (PCBKF105) flame sensed when no flame should be present. And the flame sensor can develop surface corrosion, causing it to send an incorrect signal to the computer. Whenever I do these types of tests on my furnace, I can usually find the flame sensor inside the rear or front access panel. Once the board sends a call to the gas valve to open, it monitors the current flow on the flame sensing rod. Responses to a detected flame depend on the installation, but can include sounding an alarm, deactivating a fuel line (such as a propane or a natural … Is Skipping Spring Air Conditioner Maintenance Really That Bad? You can use a Phillips screwdriver for this entire part. This is a safety mechanism. The flame detection response can depend on its fitting. Flame Sensor: A Crucial Part of a Furnace, Furnace Transformer - What It Is and How Does It…, Furnace Thermocouple - The Ultimate Guide, Inducer Motor and Blower: Why Your Furnace Needs One. The metal end of the flame sensor can rust over time. If a wire is attached to the sensor, you may have to detach it to give yourself more room. The flame sensor is an essential part of the furnace’s safety system. One of the most common causes of an otherwise fully operative furnace failing to produce heat is a problem with the flame sensor.. What a Flame Sensor Does. This is where the flame sensor comes in. You can do this by flipping the switch on your circuit breaker to the off position. A flame sensor detects the presence of fire or flames. Like many components and parts found throughout your HVAC system, flame sensors can malfunction on their own and are important to replace before they fail completely. The multimeter should be giving you a high resistance reading. This has to be measured correctly or an accident may occur, such as an explosion. The furnace’s computer uses the signal from the flame sensor to confirm a successful ignition and turn off the igniter. Finally, you are able to turn the power back on at the circuit breaker and the furnace. One such component is the flame sensor. This sensor completely address the turn off and turn on issues I was having with my hayward heater. How much should it cost to replace? The last thing you want is to be dealing with a broken furnace or malfunctioning sensor in the middle of winter. The rust builds up and prevents the flame sensor from producing the current that tells the control board that it detects the flame. On most modern units, this shutdown can happen up to three times before the system goes into a lockout and sits for an hour before it … You may also notice a sensor filled with corrosion and soot. Flame rods are found on nearly all induced draft burner systems and on many forced draft burners. All gas dryers operate … During ignition your furnace’s igniter will use a flame or a hot surface to ignite the gas that heats your air. In the end, your main goal is to have your home nice and warm. A flame detector is a sensor designed to detect and respond to the presence of a flame or fire, allowing flame detection. The furnace’s computer uses the signal from the flame sensor to confirm a successful ignition and turn off the igniter. Remove the front of the dryer cabinet to access the dryer flame sensor. This can include the cost of travel and the diagnostics charge. The other possible problem is that the flame sensor has gone bad. It will shut down the unit even if it is producing heat. It is also important to note that the flame sensor is extremely sensitive and delicate. Then, it interacts with the furnace’s control board to shut down the unit if necessary and prevent an explosion. The word sensor can be defined as an electrical device that is supposed to sense a feature or activity. Thermocouples are used on standing pilot furnaces that have pilot lights. This current has to be on the proper level to function. A thermocouple or flame sensor is a device used to control gas flow in gas water heaters.On older-style heaters with standing pilot lights, the device is typically called a thermocouple, while on newer units with electronic ignition, the same (or virtually the same) device is called a flame sensor.For our purposes, we'll refer to both devices as the thermocouple. Will experience this winter level to function level to function sensor every two to three.... Skipping Spring air Conditioner maintenance Really that bad control board that measures this reading once the cycle. The modern furnace has an Infrared type flame sensor, it is cracked, do... Discrepancies in resistance, you can test this by referring to the manufacturer ’ s instructions due... Should light up working principle is to create a current of electricity to wipe off any dust or from... Every two to three years topic you ’ re working on or researching. 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