A non-working furnace during the winter is a major source of frustration. If your furnace isn’t working, it may be because it is not igniting properly. Of course, the question then becomes, “Why is my furnace not igniting?” To help you out, the team at BVS Home Experts is here to troubleshoot furnace ignition problems.
Contact us today for furnace repair in Sugar Land, TX!
Types of Furnace Lighting Systems
Before going into furnace ignition problems, it helps to understand different furnace lighting systems. Modern gas furnaces use three main types of ignition systems:
- Standing pilot light systems use a continuous flame that heats as the thermocouple injects gas. Standing pilot light systems are also called OFF/ON/PILOT systems.
- Intermittent pilot light systems also use a pilot light but only turn the flame on when the furnace starts to heat.
- Hot surface ignition systems don’t have a pilot light and instead use a hot metal fork. When the furnace comes on, the fork heats up, and the valve opens, igniting the gas.
Common Reasons Why Your Furnace Is Not Lighting
So are you wondering, “Why is my furnace not igniting?” There are several potential culprits.
Gas Line Problems
Natural gas requires the right mixture of air, gas, and heat to properly burn. If the ratio is off, the furnace can’t start a sustained combustion reaction and won’t ignite. Leaks in your gas line can lower the gas content in your furnace, causing it to sputter out before it can start heating. Gas lines can also become blocked with dirt, debris, and tree roots.
Gas lines can also leak fumes into your home, which can pose a health hazard. If you suspect you have a gas leak, you should contact an expert to perform a test to identify and patch leaks.
Malfunctioning Pilot Light
Pilot light systems create a small flame that opens the gas valve. If the pilot light is too low, it can’t open the valve and won’t let gas through. Pilot lights can go out because the electrical system that lights them malfunctions. If this is the case, you may need to replace your pilot light.
You can check your pilot light by looking at the color. Under normal operation, it should glow a bluish color. If the flame burns yellow or red, it means that the gas is undergoing incomplete combustion. Incomplete combustion reactions can form harmful gasses like carbon monoxide, so be sure you promptly address any pilot light issues.
Miscalibrated Thermostat
The thermostat detects temperatures and tells your HVAC when to turn off and on. If the thermostat sensor is damaged or dirty, it might register temperatures incorrectly and shut off the furnace before it’s done.
The result is your home might have cold pockets, and all the constant turning on and off can raise your energy bills. You may also be able to fix the problem by changing where your thermostat is set.
Dirty Gas Burners
Another common issue that causes furnace ignition problems is dirty gas burners. Just like other parts of your furnace, gas burners can collect dirt and dust, which can clog the burner. The consequence is your system has to turn up the heat to get the same performance, which uses more energy. Dirty burners can also reduce combustion efficiency, creating carbon monoxide and other noxious gasses.
Resetting Your Ignition
In some cases, you can reset your furnace ignition. First, make sure you turn off all power to the furnace, or else you risk an electric shock. Next, remove the front panel of the main burner unit using a screwdriver.
Find the ignition unit; there should be a switch on it. Flip it to the off position and wait for at least 10 minutes. Flip the ignition unit back on and replace the burner front panel. Next, return power to the furnace and test it to see if your ignition problem is fixed. If resetting your ignition unit does not work, contact a professional to address the issue.
Do I Need to Replace a Furnace With Faulty Ignition?
The older your furnace gets, the more likely it is you will have an ignition problem. If your furnace is more than 10 years old and you have to get frequent repairs, we recommend replacing your system.
Of course, it depends on the specific problem. Sometimes, solving ignition problems is simply a matter of cleaning your burners or fixing a gas line. If you are not sure, you can contact professional HVAC technicians to diagnose your problem and discuss whether replacement is the right option for you.
Gas Ignition Troubleshooting FAQ
Below are some of the most common questions about why your furnace might not be igniting.
Yes, a faulty ignition device can cause a fire in some cases. If the ignitor has difficulties starting, it can create large sparks that might ignite the gas and cause an explosion. You should never try to run a furnace with a faulty ignition.
It depends on the specific kind of ignition system your furnace has, but most last anywhere between five and seven years on average. If your furnace ignition is older than seven years old, you should consider replacing it with a new one.
You can extend your furnace ignition’s lifespan by getting regular furnace maintenance, which includes inspecting gas lines, changing furnace filters, and cleaning gas burners. You can extend your burner’s life by an additional two to three years.
Schedule Furnace Repair in Sugar Land, TX, Today!
Now that you know the answer to the question, “Why is my furnace not igniting?” read our blog to learn about some useful furnace safety tips. If you would like to schedule furnace repair service in Sugar Land, TX, contact BVS Home Experts online or call today at (281) 916-8699 to schedule an appointment! Learn more about what we do.
