Modern furnaces typically forego the old-style pilot lights and instead use a more modern hot surface igniter system. These components have a shockingly descriptive name. Unlike more complex ignition systems, a hot surface igniter passes enough electricity through a plate (the surface) to heat it until glowing red. This hot surface ignites the gas when your furnace needs to light.

Unfortunately, this simple device can also be a source of some trouble. Hot surface igniters often fail on older furnaces, but what if you've already replaced your igniter? Even worse, what if your hot surface igniters keep failing? There are a few possible reasons for repeated failure, and this guide will help explain some potential causes.

Understanding How Hot Surface Igniters Fail

Hot surface igniters can fail for a wide range of reasons. When your furnace igniters, the hot surface igniter goes through a heating and cooling cycle. While these components are highly robust, years of usage can wear them out and cause them to fail. However, anything that accelerates the wear on the hot surface igniter (such as short cycling) can result in premature failure.

In some cases, igniter failures result from direct damage to the ignition surface or its base. If your furnace is running inefficiently, it may produce excessive carbon build-up, known as soot. This soot will coat many interior surfaces of your furnace, including the igniter. Since hot surface igniters are relatively brittle, cleaning them without causing damage can be challenging.

Finally, electrical issues are another common cause. Hot surface igniters expect a reasonably precise voltage. Overvolting the igniter will cause it to wear out more quickly or, in the case of sudden voltage spikes, burn out immediately. Voltage issues in your furnace can also affect other electrical components, including the control board.

Addressing Repeated Hot Surface Igniter Failures

Repeated igniter failures are a sure sign that your furnace has another underlying issue. Unless you're unlucky enough to receive many defective parts, multiple failures are likely due to inefficient operation, frequent cycling, or underlying electrical issues. Failing to address these problems will cause your igniters to fail continually, in addition to causing other problems with your furnace.

The best way to avoid these issues is to rely on a professional HVAC technician to diagnose any issues with your furnace. Blindly replacing parts may not solve the underlying problem. However, professionals know how to thoroughly investigate any issue with your furnace, allowing them to treat the underlying cause of your heating issues and not just the symptoms.

For more information on furnace repair, contact a company near you.