Have you ever woken up on a chilly morning to find your furnace stubbornly refusing to kick on, leaving you shivering and wondering what went wrong? One of the most common culprits behind a cold house is a pilot light that has gone out. While it might seem intimidating, relighting a pilot light is often a straightforward process that homeowners can handle themselves, saving time and money on potentially unnecessary service calls. Understanding how to safely and effectively relight your furnace’s pilot light is a valuable skill that can keep your home warm and comfortable throughout the colder months, and prevent potential problems down the road.
A furnace is a crucial appliance for many homes, particularly in regions with cold winters. Without it, discomfort is guaranteed, and there’s even risk of pipes freezing and bursting, leading to costly repairs. Being familiar with basic furnace maintenance, like relighting the pilot, can prevent these problems. By tackling this task yourself, you’ll avoid waiting for a technician and restore heat to your home promptly, creating a more comfortable and safer living environment for you and your family.
What tools do I need and how do I relight the pilot light safely?
Where exactly is the pilot light located on my furnace?
The pilot light on most furnaces is located inside the main burner compartment, near the burner assembly. You’ll typically find it behind an access panel that needs to be removed or opened. Look for a small nozzle or burner with a tiny opening, often surrounded by a metal shield or bracket. You may need a flashlight to get a good view inside the compartment.
To find the pilot light more easily, look for the gas valve. The gas valve is a prominent component with gas lines feeding into it. The pilot light assembly is almost always directly adjacent to the gas valve, as it needs to control the gas flow to both the pilot light and the main burner. The pilot light assembly will consist of a small burner with a thermocouple (a small metal rod) next to it. This thermocouple is essential for safety; it senses the presence of the pilot flame and allows the main gas valve to open. If you’re having trouble locating the pilot light, consult your furnace’s manual or look for a diagram on the inside of the access panel. Some furnaces have a viewing window that allows you to see the pilot light without removing the panel, but this is less common in older models. If you’re still unsure, it’s always best to consult with a qualified HVAC technician to avoid any potential safety hazards.
What safety precautions should I take before lighting a pilot light?
Before attempting to light a pilot light on a furnace, prioritize safety by ensuring there’s no gas odor present, turning off the gas supply valve to the furnace, and allowing any accumulated gas to dissipate for at least five minutes. This reduces the risk of a potential explosion or fire.
It’s crucial to trust your senses. If you smell gas, do not proceed with lighting the pilot light. Immediately evacuate the area, and contact your gas company or a qualified HVAC technician. Do not attempt to locate the source of the leak yourself or use any electrical devices that could create a spark. Ventilation is also important. Open windows and doors to help dissipate any lingering gas fumes before you even think about touching the furnace. Beyond smelling for gas, it’s prudent to visually inspect the area around the furnace for any obvious signs of damage, such as frayed wiring, loose connections, or gas leaks. Make sure the area is clear of flammable materials like paper, rags, or cleaning supplies. Having a fire extinguisher nearby is always a good idea, although you should only use it if you are confident in doing so safely and without putting yourself at risk. If anything seems amiss, call a professional – gas appliances can be dangerous if not handled properly.
How long do I typically need to hold the reset button down?
Typically, you’ll need to hold the reset button (or pilot button) down for 30-60 seconds while attempting to light the pilot light on your furnace. This allows the thermocouple to heat up and generate enough voltage to keep the gas valve open, maintaining the pilot flame.
Holding the reset button is crucial for a specific reason: it manually overrides the safety mechanism that prevents gas from flowing when the pilot light isn’t lit. The thermocouple, a small metal rod near the pilot light, generates a tiny electrical current when heated by the pilot flame. This current tells the gas valve that it’s safe to stay open. When you first try to light the pilot, the thermocouple is cold, so you need to manually hold the valve open (by pressing the reset button) long enough for the thermocouple to heat up and start generating its own current. If the pilot light consistently fails to stay lit after releasing the button after 60 seconds, there might be underlying issues such as a dirty or faulty thermocouple, a blocked pilot orifice, or a problem with the gas valve itself. In these cases, it is always best to consult a qualified HVAC technician for diagnosis and repair. Attempting to troubleshoot gas-related issues without proper knowledge and equipment can be dangerous.
What if the pilot light keeps going out after I light it?
If your pilot light ignites but won’t stay lit, the most common culprit is a faulty thermocouple. The thermocouple is a small, metal rod that sits in the pilot light flame. Its job is to sense the heat and tell the gas valve to stay open, continuously supplying gas to the pilot. If the thermocouple is dirty, damaged, or has failed, it won’t generate the necessary electrical signal, and the gas valve will shut off, extinguishing the pilot light.
Before immediately replacing the thermocouple, try a few troubleshooting steps. First, ensure the pilot light flame is actually engulfing the thermocouple. A weak or improperly adjusted flame might not provide sufficient heat. You can often adjust the pilot light flame using a small screw near the pilot assembly. Refer to your furnace’s manual for specific instructions. Next, check for any dirt or debris on the thermocouple. A gentle cleaning with fine steel wool or a non-abrasive pad might improve its performance. Make sure to turn off the gas supply before attempting any cleaning or adjustments.
If cleaning and adjusting the flame don’t solve the problem, replacing the thermocouple is usually the next step. This is a relatively inexpensive and straightforward repair that most homeowners can handle with basic tools. However, if you are uncomfortable working with gas appliances, it’s always best to call a qualified HVAC technician. Other potential causes of a pilot light that won’t stay lit include a faulty gas valve, a blocked pilot light orifice, or insufficient gas pressure. These issues are more complex and typically require professional diagnosis and repair.
What does a properly lit pilot light flame look like?
A properly lit pilot light flame is typically a crisp, blue flame with a small yellow tip. It should be steady, consistent, and reach high enough to reliably heat the thermocouple or flame sensor, ensuring the main burner ignites when called upon. It should not be weak, flickering, or mostly yellow.
A healthy blue flame indicates complete combustion of the gas. The small yellow tip is normal and signifies a very small amount of incomplete combustion. The flame should envelop the thermocouple or flame sensor. This device is crucial; it generates a small electrical current when heated by the pilot light. This current tells the gas valve that the pilot is lit, allowing the main burner to receive gas when heat is needed. If the pilot light is weak or unstable, it won’t properly heat the thermocouple, and the furnace will fail to ignite. If the pilot light is mostly yellow, large, or smoky, this indicates incomplete combustion, potentially due to a dirty burner, insufficient airflow, or a gas pressure issue. A yellow or wavering flame can also produce carbon monoxide, a dangerous, odorless gas. Should you notice these issues, it is essential to turn off the gas supply to the furnace and contact a qualified HVAC technician for inspection and repair. Never attempt to troubleshoot gas-related problems yourself if you are not trained and qualified to do so.
Is there a difference in the procedure for older versus newer furnaces?
Yes, there is a noticeable difference in the pilot light lighting procedure between older and newer furnaces. Older furnaces typically require manual lighting of the pilot light using a match or lighter, while newer furnaces often feature electronic ignition systems that automatically light the pilot or ignite the burners directly without a standing pilot.
Older furnaces are equipped with a standing pilot light, a small, continuous flame that constantly burns to ignite the main burners when heat is called for. To light this type of pilot manually, you’ll usually need to locate the gas valve near the furnace, turn the control knob to the “Pilot” setting, depress and hold the knob while lighting the pilot light with a long match or lighter, and then continue holding the knob for a period (usually 30-60 seconds) to allow the thermocouple to heat up and keep the pilot lit. After the thermocouple heats up, release the knob and turn it to the “On” position. Newer furnaces, especially those with electronic ignition, eliminate the standing pilot to improve energy efficiency. These furnaces may have either an intermittent pilot ignition (IPI) or a direct spark ignition (DSI) system. In an IPI system, the pilot light is only lit when heat is needed, using an electronic spark to ignite the pilot. With DSI, the main burners are ignited directly by an electronic spark, skipping the pilot altogether. These systems typically involve simply turning on the furnace via the thermostat and allowing the electronic control board to handle the ignition process automatically. If the furnace fails to ignite, safety mechanisms will usually shut off the gas supply. In those cases, troubleshooting might require professional assistance.
How do I know if the gas valve is open properly?
When lighting a pilot light on a furnace, you’ll know the gas valve is open properly when the valve handle is aligned parallel to the gas pipe running to the furnace. When closed, the handle is perpendicular to the pipe. You should also be able to smell a faint odor of gas (or hear it hissing very quietly) when depressing the pilot button, assuming the valve is open and the pilot gas line is clear.
The position of the gas valve handle is the primary visual indicator. Think of it like a water faucet: when the handle is lined up with the pipe, it’s open, allowing gas to flow. If the handle is turned 90 degrees (perpendicular) to the pipe, it is closed, blocking the gas flow. Double-check that the handle is fully aligned with the pipe. Sometimes, it can appear aligned, but a slight turn is still needed to fully open the valve.
After confirming the valve position, carefully listen and smell for gas near the pilot light assembly when you depress the pilot button. Be extremely cautious! Gas leaks are dangerous. If you smell a strong odor of gas or suspect a significant leak, immediately shut off the main gas supply to the house and call your gas company or a qualified HVAC technician. Do not attempt to light the pilot if you suspect a large leak. If you can hear or smell a small amount of gas when depressing the pilot button with the valve properly aligned, that’s an indicator the valve is open and gas is reaching the pilot.
And that’s all there is to it! Hopefully, your furnace is now roaring back to life, keeping you warm and cozy. Thanks so much for taking the time to read this guide – we really appreciate it. If you run into any other home maintenance mysteries, be sure to swing by again; we’re always adding new tips and tricks!