A modern gas furnace is a home heating appliance that typically runs on natural gas. It has three parts: the gas valve, igniter, and flame sensor. All of these components work together to provide sufficient heat to all areas of your home.

The igniter fires up your furnace by creating a flame. Your gas valve controls your fuel supply by adjusting the amount used and controlling the direction of the gas. The flame sensor acts as a watchdog by preventing gas leaks. It will cut off the gas supply to your furnace when the flame is out.

Types of Gas Furnaces

Getting a gas furnace fixed or replaced can be confusing, especially if you don’t know what you’re working with. To dispel any confusion, it’s important to know that there is more than one kind of gas furnace. Most residential homes use one of three different kinds of gas furnaces to produce sufficient heat: the single-stage system, the two-stage system, and the modulation system.

Single-Stage System

One of the earliest gas furnace models is the single-stage system, a simple setup that uses a basic on/off feature. It was invented in the 1930s as a cheaper alternative to traditional home heating systems. The single-stage furnace is ideal for the harshest climates because it heats your home at an optimal temperature. It’s cheaper to purchase and install. However, you cannot adjust the output because it always runs at full capacity when it’s on. So, if you want to decrease the heat output, you’ll need to turn your furnace off. Of course, maintaining a consistent temperature by doing this is the function of your thermostat.

Two-Stage System

A two-stage system has the edge over the single-stage system in several ways. There’s plenty of room to adjust the output on a two-stage furnace when it gets too hot. It can auto-adjust once your home reaches an ideal temperature. The two-stage furnace works like a slow cooker in that it keeps your home at a steady temperature for a long period of time. This is especially helpful when the weather is mild. The two-stage system runs quietly and has a built-in filtration system designed to help keep your air clean. The only drawback is that it’s very expensive.

Modulation System

A modulation system sets itself apart from its peers in several ways. It’s controlled by a wireless thermostat that moderates heat output during operation. The wireless thermostat works hand-in-hand with a variable speed blower to distribute comfortable temperatures throughout your home. Your speed blower controls airflow to ensure a comfortable indoor climate. This helps the modulation system run smoother while saving you money on energy costs. Like the two-stage system, it is more expensive. But because it heats your home using less energy, it is a worthwhile investment.

What Gas Does a Gas Furnace Use?

All three furnace types just mentioned have one thing in common: they need fuel to run. There were once two types of gas fuel sources commonly used for furnaces: propane and natural gas. Although propane is still available, it is now used far less frequently since it requires a separate tank. The most popular choice for today’s furnaces is natural gas. Due to improved combustion, natural gas can heat up your home in minutes.

Gas is a cheaper alternative to electricity because it’s more efficient. Electricity costs more to produce less heat for your home, making it a less energy-efficient source than natural gas.

What Happens When Your Gas Furnace Goes Out?

Like most appliances, gas furnaces can go out at any time. The problem can be something small like trouble with your gas line. Or your flame sensor may be clogged with dirt or grime. This could cause your system to shut down completely. In this case, you’ll need to hire a licensed technician to address the issue.

In other cases, your problem may even be the result of a power outage in your area. You can take steps to re-light your furnace with care. The following is a safety guide to lighting up your gas furnace.

How to Re-Light Your Gas Furnace

Blue is the color of a healthy pilot light. It means your furnace is getting enough gas to function properly. The pilot light says a lot about what’s going on with your heating system and when it’s time to call a service technician.

If the flame on your pilot light is red or yellow, something is wrong. For some reason, you’re not getting enough fuel to warm up your home. The problem may be a dust or grime buildup in the pilot’s opening. You should call a service technician to inspect your furnace for signs of a clog.

Another issue that impacts your pilot light is airflow restriction. A gust of wind can snuff out your pilot light. It can come from a damaged chimney or flue. In other cases, leaky ducts may be to blame. When this happens, you can re-light your own pilot light by following these steps.

A Step-by-Step Guide to Lighting Your Gas Furnace

The first step to lighting your pilot light is to turn your furnace off. Wait for the furnace to stop running before you do anything else. This takes only a couple of minutes. Do not adjust any settings until it is completely off.

Your next step is to read the instructions on lighting your pilot light. This information is usually located right on your unit. If you can’t find it, you should check the operating manual or look it up on the manufacturer’s website. The instructions should tell you where the gas valve is. If they don’t, you can locate it by checking for a knob or a switch at the bottom of the furnace. When you do, turn it to the “Pilot” position.

Next, reset the pilot light. Hold the red reset button for a couple of seconds. If your furnace is automatic, it should light up right away. If not, use a long match or lighter to light up your pilot light. Turn the knob to the “On” position and observe the flame. If it’s burning steadily, then your furnace is working just fine. Be sure to check the area around your furnace for any drafts. If you notice any cold air coming in, locate the source. It could be your ductwork or something as simple as an open window.

If you’ve tried to follow these steps and you’re still having trouble, call a professional. A pilot light that keeps turning off is a sign of a greater problem. You may need to have the inside cleaned by an HVAC technician.

When to Call the Professionals

If you’re having trouble lighting your furnace or you’re unsure of how to do it, call in the experts. At J&W Heating and Air, we’ll work to help you get your gas furnace going. Our technicians are fully trained and licensed and can perform furnace repair and replacement. In fact, we handle a complete spectrum of heating and cooling installation, repair, and replacement throughout the Jacksonville area. We work with both natural gas and electric furnaces to suit your needs. If you have any HVAC concerns, call us today to schedule a visit.

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