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Gas furnaces use either a thermocouple or a flame sensor. Both are safety devices used to sense the flame and control the gas that flows into the appliance. Without a flame, the flame sensor prevents the flow of gas at the valve, preventing a situation where gas flows into the appliance without a flame to burn it. For this reason, you should practice regular flame sensor cleaning.
Thermocouples and flame sensors are simple devices, however, they do wear out over time. Once a flame sensor begins to malfunction, you should look to replace it with a new one. Flame sensor cleaning is as important as any other home appliance maintenance routine.
The thermocouple is smaller in size and used with continuously burning flames with standing pilots. It is positioned within the flame, which means the tips are continuously heated whenever there is a flame. Once the flame goes out, the thermocouple’s tip cools, signaling the thermocouple to block the passage of gas past the valve.
On the other hand, flame sensors are typically used in electrically ignited flames and not standing pilot flames, as is the case with thermocouples. Flame sensors might sometimes include a hot surface ignition or intermittent pilot model. The unit has an electric igniter that lights up the gas, while the flame sensor ascertains that the burner is ignited successfully. Whenever there is an issue with the ignition, and the gas burner fails to ignite, the flame sensor will automatically block the gas coming to the burner.
When shopping for a new flame sensor or thermocouple to replace the old malfunctioning one, you should make sure it is compatible with the furnace model in your house. Most thermocouple manufacturers offer universal models that will work efficiently with any standard furnace model.
You should check the length of the thermocouple or flame sensor on its packaging – it’s often indicated in inches. This is the length of the lead, which happens to be the flexible metallic wire between the thermocouple tip sitting within the pilot flame and the end attached to the gas valve.
On the other hand, flame sensors are less universal, meaning you will have to find a perfect match for your kitchen’s flame model. With so many options out there, you can compare the prices to find a high-quality flame sensor that is also 100 percent compatible with your flame model at a cost-friendly price. You can also compare the flame sensor sold online with those found at your local distribution store. If you urgently need one, you can look for a dealer who has the flame sensors in-store.
It is not rocket science replacing a malfunctioning thermocouple. Although it’s highly recommended that you hire professionals for the job, you can replace the thermocouple yourself by following basic steps.
Your thermocouple is successfully replaced and up and running again and more efficiently. However, it is important that you test for any possible leaks after completing the replacement process, just to be sure that gas is not leaking.
Similar to a thermocouple, replacing a flame sensor can be a hard task and should usually be left to the pros. However, this does not make DIY’ing impossible. By following the following steps and guidelines, you can address this issue safely. Again, follow the instructions outlined by the manufacturer of that specific model you are about to replace.
If you are stuck or feel like avoiding DIY altogether, the professionals at Whipple Service Champions are the team to call for help replacing your flame sensor.