Why Heat Sensor of a Furnace Is Important?
With winter just around the corner, you should check your heating system. A mid-season breakdown of a heating and cooling system is one of the most significant inconveniences no one should face.
However, furnace failure is pretty common in homes across America.
Scared of Your Furnace Stalling?
Routine maintenance and tune-ups can ensure the reliability of your heating and cooling system all season long. While you can clean some components, there are other elements you can’t reach.
Professional services are always best. It’s advisable to schedule your yearly furnace tune-up in autumn, just in time for winter.
Why do you need a professional’s touch? There may be other elements you need to familiarize yourself with before conducting any DIY efforts.
One sophisticated element that needs gentle handling is your flame sensor. Need to know what it is and what to do with it?
Here’s everything you need to know about a furnace flame sensor.
What is the Furnace Flame Sensor?
You might have a bad flame sensor if your furnace issues are often related to ignition components. An extinguishing flame, delayed ignition, or a pilot light that won’t turn on may stem from a dirty flame sensor.
A flame sensor is a sleek metal rod in your burner assembly. It is inserted through a burner chamber into the pilot light.
What Does the Furnace Heat Sensor Do?
The flame sensor or metal rod near your pilot fire is connected to an electrical box through a single wire that transmits signals to a separate control panel.
If you have an oil or natural gas furnace, they are more sophisticated than you think. Even an older model comes with a safety feature or two.
An oil, electric, and gas furnace each has a gas valve that facilitates the release and withholding of fuel supply. Transmission from the flame sensor and control board automatically facilitates fuel supply for efficiency and safety.
Sounds complicated? Don’t worry. We are here to help.
How Does The Furnace Flame Sensor Control My Heating System?
The flame sensor is just a sensor and cannot control your heating system alone. The flame sensor sends an electric current through the ignition surface toward the control boards.
Together, the flame sensor and controls close off the gas or oil supply, preventing burners from igniting the flame.
What Does the Flame Sensor Sense?
The name sums it up. Your flame sensor senses whether there is a flame or not.
A flame sensor is sensitive to temperatures. Most furnace flame sensors are directly within an open fire chamber of a burner assembly.
They determine whether or not the pilot light is burning in only a few seconds. If there is a fire, the temperature of the metal rod is higher than when there is none.
What happens if my flame sensor stops working?
If a flame sensor is bad, it cannot determine whether the flame burns or not. You can expect either one of these two effects:
- Your furnace won’t fire up.
- It results in a surplus of wasted fuel.
Your flame sensor is likely hindering your furnace from powering on unless it isn’t plugged into a power source but needs electricity to function.
Newer furnaces have various safety precautions in case of a faulty flame sensor:
- Screw shut the gas valve (remove any avenues for supply to flow through)
- Cut the power source (for intermittent pilot flames)
- Shut down burners (for standing pilot flames)
- Initiate a flame sensor restart
However, not every furnace has that safety process. Your furnace may not have that security measure in its process against a broken flame sensor.
Dangers of a faulty flame sensor
An older furnace flame sensor may not be able to stop a gas furnace from releasing gas, leading to a potentially hazardous amount of unburned gas.
Gas may leak out of other elements on your burner assembly and stagnate in your air. Gas may seep into your ductwork if your furnace is linked to a central air conditioning system.
Your air conditioner may distribute the gas around your home, causing a dangerous amount of carbon buildup indoors.
How a bad flame sensor can impact your health?
It can lead to various health and safety risks. Too much carbon monoxide in your home can lead to an explosion when ignited.
That much carbon monoxide in your home, distributed through your air conditioning, can cause fatal carbon monoxide poisoning.
Common Causes for a Dirty Furnace Flame Sensor
Exploding and poisoning are significantly dangerous risks for a lesser-known element in your furnace to cause. What’s more troubling is a buildup of such seemingly harmless or unavoidable debris in your furnace may be the root cause.
Inevitable elements such as dirt and soot settling on or within your furnace can clog chambers and filters, indirectly impacting your flame sensor.
Always inspect the state of all the burning components of your heater.
Clean whatever needs cleaning, fix whatever needs repairs, and replace whatever needs to be replaced to avoid known and unknown dangers from occurring in your home.
Is My Furnace Flame Sensor Broken?
Are you tired of suffering from a furnace malfunction? Familiarize yourself with your heater at home before inspecting the unit.
You should know what irregularities to look for and which warrant immediate attention. Problems with your flame sensor affect the rest of the heating process.
Call a professional to clean, fix, or replace the unit if you notice something wrong with your furnace flame sensor. However, you should know how to tell if there’s something wrong with it or not before calling anyone else for help.
There are many ways you can tell if your flame sensor is bad. Some methods have you reaching too far into your furnace than you are comfortable doing.
Your best bet is to check the flame itself. Inspect your pilot flame for any of these symptoms:
- Flickering
- Burning low
- Burning yellow
- Delayed or won’t ignite
If you notice one or more of these symptoms, your furnace may have a faulty or dirty burner assembly. Your flame sensor cannot work properly with even just one compromised element in its lineup.
Fortunately, it is easy to clean a furnace flame sensor.
How to Clean Your Furnace Flame Sensor?
Not every heating and cooling system is built the same. Getting to your furnace flame sensor may differ. However, you can still clean your flame sensor, as stated below.
Always ensure all power sources and supply lines are shut or closed. Gather these materials rubber gloves, clean cloth, oxalic acid, emery cloth or light grit sandpaper, warm water, and misting spray bottle.
- Follow the single wire attached from the power controls (integrated thermostat or furnace control panel) to the flame sensor to locate it.
- Carefully remove the furnace access cover once you reach the burner assembly.
- Remove any screws holding the rod in place.
- Separate the flame sensor from the mounting screw or protective vessel.
- You may notice discoloration on the porcelain insulation.
- Gently rub it with a diluted mixture of oxalic acid and warm water using a clean cloth.
- Only use emery cloth or sandpaper to scrub off residue and contamination on the rod. (Steel wool is a viable alternative if you scrub lightly. The best option is still an emery cloth to lessen risks for damage.)
- Wipe off debris with a damp cloth before placing the flame sensor back.
- Inspect the remaining adjoining elements, such as screws, for residual gas and soot.
- Clean other elements with a damp cloth gently and replace corroded screws saturated with soot.
Remember to place everything back where you found them before you power your furnace back up.
When it comes to your flame sensor, it’s best to clean it once a month. Depending on your usage, it may develop contamination more rapidly.
When Should I Replace the Furnace Flame Sensor?
However, you can only clean corrosion and rust partially from your furnace. While it may look “clean enough” to you, your furnace flame sensor may not be as responsive as it should be.
Replace a corroded or faulty furnace flame sensor before it worsens.
You can clean and replace a mounting screw, but don’t attempt to change out wires on your own. If more crucial components need to be replaced, you should leave them to the experts.
How Much do New Furnace flame sensors cost?
A new sensor won’t cost you much. Assuming furnace flame sensors cost anywhere between $10 and $20 is a safe assumption.
It is technically just a piece of metal—however, the quality, compatibility, and installation matter more than finding an affordable one.
Before buying a new sensor, remember to find one that fits. Your furnace access cover may not shut if it’s too large or long to fit in the chamber.
If your furnace flame sensor needs to be replaced, call heating and cooling system specialists for its management.
The Importance of Furnace Maintenance
Upon cleaning your furnace flame sensor and other components, don’t risk the rest of your unit on “clean enough.”
Rust tends to infect surrounding elements, which can spread quickly, especially if you have a metal furnace frame. Internal corrosion in your furnace may creep to external elements and impact the entire furnace beginning with your flame sensors.
What Do I Do If There are Signs of Corrosion?
Immediately check the gas valve if you notice rust anywhere in your unit.
If you see any corrosion on the gas valve, remove as much of it as possible with an emery cloth. You can then add some baking soda and lime. Let the mixture sit before scrubbing it off with an old toothbrush.
The corrosion may infiltrate the internal connection and make it harder to manage your gas supply, especially in an emergency.
Heating and Cooling System Maintenance, Tune-Ups, & Repairs in Sandy, Utah
You don’t have to let it get as far as corrosion. You can prevent anything from going wrong with your furnace.
Whether to prevent the flame sensor from getting dirty or the thermostat from malfunctioning, routine maintenance is always helpful.
Regular cleaning and inspection can lengthen their lifespan and increase the overall reliability of your furnace.
One Stop Heating & Air Conditioning
Troubles with your furnace flame sensor? Is your furnace acting up? Is your furnace down for the count? Say no more. Our top-rated team of experts is just a call away.
Entrust us with your furnace repair and tune-ups. We even provide emergency heating repair round the clock for more urgent furnace issues.
If you are tired of your old furnace, it might be time for a newer, safer, and more efficient unit! Call us for furnace replacement and installation services today!
