How to Fix a Faulty Ignition in Your Furnace

HVAC Installer Strips Small Wires for a new Residential Furnace
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Is your igniter sparking but not catching your burner? Here’s a list of potential problems and how to solve them.   

What's Causing Your Faulty Ignition?

  • Loose pilot valve wiring. Your pilot valve is an electronic solenoid that releases gas in order to ignite your pilot. The wiring that sends signals to your valve
  • Damaged pilot lines. Pilot lines feed gas into your pilot and allow your burner to cycle on. Occasionally, pilot lines can become obstructed. This is most common toward the pilot ignition area. Burning fuels create moisture, which can cause rust and other corrosion. Mechanical failures within your furnace can bend and damage your pilot line. A bent line will reduce the gas load and result in a faulty ignition. 
  • Clogged pilot orifice. Moisture and regular heat can cause your pilot line to deteriorate and corrode. A damaged line can become clogged and reduce the flow of gas.
  • Faulty pilot gas valve. Your pilot’s gas valve is what releases your ignition gas. Your pilot valve can fail due to age or mechanical damage. A broken gas valve will block all gas from entering the pilot or igniting your burner.
  • Problematic control module. Control modules are electronic units that control your HVAC’s heating and cooling cycles. A broken control module will disconnect your furnace from your thermostat and result in a faulty ignition.

    Fixing your furnace

    Furnaces utilize electronic and gas systems to heat your home. Working on your unit without the proper training can result in personal injury and serious damage to your home. DIY repairs can also prolong existing furnace issues and cause other expensive repairs. It’s a good idea to hire a pro to make your furnace repairs. Professional HVAC technicians will quickly diagnose the problem and offer a long-term solution.

    Not all furnace fixes require working with dangerous electrical or gas systems. Here are two repairs you can make yourself:

    • Replace the air filter. Dirty filters restrict airflow and affect the overall performance of your furnace. Swap out your older or clogged filters.
    • Check the gas line. Your furnace’s gas line has an on-off valve. Be sure the valve isn’t off or partially closed.