A Step-by-Step Guide
A furnace that won’t stay lit can be frustrating, especially during the colder months. One of the most common culprits is a dirty flame sensor. The flame sensor is a small metal rod that detects whether your furnace’s burners are ignited. If it gets covered in dirt or corrosion, it won’t function properly, causing your furnace to shut down. In this guide, we’ll explain how to clean a flame sensor on a furnace and help you get your heating system running again.
Signs of a Dirty Flame Sensor
Before jumping into the cleaning process, it’s important to know when your flame sensor needs maintenance. Here are some common signs:
- Furnace turns on but shuts off after a few seconds
- Heater repeatedly short cycles
- Furnace won’t stay lit
- A blinking error code on your furnace control board
- Heating system blowing cold air
If you’re experiencing any of these problems in Troy, Piqua, Sidney, Bellefontaine, Celina, or Tipp City, it may be time to clean or replace your furnace flame sensor.
How to Clean a Flame Sensor on a Furnace
Cleaning a flame sensor is a straightforward process, but if you’re not comfortable working with your furnace, it’s always best to call a professional. Follow these steps to safely clean the sensor:
1. Turn Off Power to the Furnace
For safety, turn off your furnace power switch or shut off the breaker connected to your heating system.
2. Locate the Flame Sensor
The flame sensor is usually found near the burner assembly inside your furnace. It’s a thin metal rod with a ceramic base, mounted with a single screw.
3. Remove the Flame Sensor
Use a screwdriver to unscrew and gently pull out the flame sensor. Be careful not to damage the surrounding components.
4. Clean the Sensor
Take fine-grit sandpaper, an emery cloth, or a soft scouring pad and gently rub the flame sensor to remove dirt and oxidation. Avoid using anything too abrasive that could scratch or damage the rod.
5. Reinstall the Flame Sensor
After cleaning, carefully place the flame sensor back in its original position and secure it with the screw.
6. Turn the Power Back On and Test
Restore power to your furnace and turn up the thermostat to see if your system ignites properly.
When to Call a Professional
If your furnace still won’t stay lit after cleaning the flame sensor, there could be a bigger issue at play, such as a faulty ignition system, dirty burners, or a damaged sensor. Lochard HVAC, Plumbing, and Service is here to help with furnace repair, heating maintenance, and HVAC services throughout West Milton, New Bremen, Anna, Jackson Center, Degraff, and Quincy.
Keep Your Furnace Running Efficiently
Regular furnace maintenance can help prevent flame sensor issues before they start. Consider scheduling an annual furnace tune-up to keep your heating system running efficiently all winter long.
Need Professional Furnace Service?
If you need furnace repair or flame sensor replacement, Lochard HVAC, Plumbing, and Service is here to help. Our HVAC experts provide reliable heating repair, installation, and maintenance to ensure your home stays warm and comfortable. Contact us today!
FAQs
Can I clean a flame sensor with alcohol?
While isopropyl alcohol can remove dirt and grime from a flame sensor, it’s not the best option for thorough cleaning. The most effective way to clean a furnace flame sensor is by using fine-grit sandpaper, an emery cloth, or a non-abrasive scouring pad to gently remove oxidation and buildup.
Can I use a dollar bill to clean a flame sensor?
A dollar bill can remove some surface dust from a flame sensor, but it won’t be effective for burnt residue or oxidation. Using fine sandpaper or an emery cloth will provide a more thorough cleaning, ensuring proper furnace operation.
How often do flame sensors go bad?
A flame sensor typically lasts 3 to 5 years, but dirt and oxidation can cause it to malfunction sooner. Regular furnace maintenance and annual cleanings can extend its lifespan and prevent heating issues.
What must I use to clean an airflow sensor?
If you’re referring to the flame sensor, you should use fine-grit sandpaper, an emery cloth, or a scouring pad to gently remove buildup. However, if you mean an airflow sensor in an HVAC system, use compressed air or a specialized sensor cleaner to remove dust and debris without damaging the component.
Can you clean a flame sensor with emery cloth?
Yes, an emery cloth is one of the best tools for cleaning a flame sensor. It’s gentle enough to remove oxidation and dirt without damaging the sensor, helping restore proper furnace operation.
