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What a Flame Sensor Does and Why It’s Preventing Your Furnace from Lighting

graphic-of-an-orange-flame

When your furnace simply won’t start up, or it starts but immediately stops, you’ve clearly got a big problem on your hands. Is your furnace just done? Do you need to replace it? Or will it require major repairs that take a lot of time and cost a lot of money? We’ve got good news for you. It may just be your flame sensor preventing your furnace from lighting, and that’s an easy fix. Here are the details.

The Flame Sensor’s Job

This component is part of your furnace’s safety mechanisms. It’s there to help you avoid disaster. It detects whether or not the pilot or ignition system has actually created a flame. When it determines that there is a flame, it allows gas to flow so your furnace will run. When it determines that there is no flame, it does not allow gas to flow.

This means that with no flame being sensed, your furnace will not run. Now, if there’s no flame, allowing gas to flow would just mean creating a gas leak. You don’t want to breathe that gas, and it poses a huge fire hazard. But sometimes the flame sensor won’t allow gas to flow even though the flame is present. Why?

What Causes Flame Sensor Failure

Chances are, the flame sensor is simply dirty! Being in close proximity to a flame all the time means that sooty buildup is very likely. It may also just be coated in dust, especially if you haven’t been getting regular furnace maintenance done. This dirt between the sensor and the flame is like a shield, stopping the sensor from detecting the flame.

Fixing the Problem

When you get heating repair in San Antonio, TX to address a faulty flame sensor, your technician will disassemble and clean the sensor so it will be able to accurately detect the presence or absence of a flame. This sounds pretty straightforward, right? But that doesn’t mean you should try to do it yourself.

First, if your DIY attempt doesn’t properly fix the problem, you could end up with that gas leak that the flame sensor was trying to prevent in the first place, which is a risk you really can’t afford to take. It’s also easy for an inexperienced homeowner to negatively affect other parts of the furnace in the process of trying to fix the flame sensor.

The other reason not to DIY is your warranty. Imagine something major goes wrong with the furnace in the future, something that’s the manufacturer’s responsibility, such as a component failing because of a manufacturing defect. If it’s under warranty, the manufacturer will cover the cost of repairs. But having someone work on your furnace without the proper licensing will void that warranty, allowing the manufacturer to refuse to pay for repairs.

Preventing Flame Sensor Issues

The best way to avoid having this happen again is to make sure you get professional furnace maintenance done every single year. Maintenance involves disassembling and cleaning the flame sensor and all the other components, as well as lubricating moving parts and inspecting and testing everything for safety and effectiveness. It’ll keep your flame sensor happy and cut down on repair needs by as much as 85%!

Our professionals are ready to take care of you when you reach out. Contact Cowboys Air Conditioning & Heating today to schedule an appointment with our professionals.

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