About The Author: Travis Baugh is a Digital Brand Marketing Manager for Bryant, where he creates clear, helpful content to guide homeowners through heating, cooling, and indoor air quality decisions. His goal is to empower readers with the knowledge they need to choose the right comfort solutions for their home—confidently and comfortably.
Your Guide To Furnace Ignitors
By Travis Baugh | Expert Review By Seth Faber - Product Manager, Furnaces
A furnace ignitor is a critical electronic component in modern heating systems that replaces the traditional standing pilot light to ignite the gas and create heat. Many Bryant gas furnaces use a silicon nitride PowerHeat™ or PerfectLight™ Hot Surface Ignitor (HSI) to electronically ignite the burners when there is a call for heat. For homeowners seeking long-term comfort and efficiency, understanding how this small but vital part functions is the key to maintaining a warm, reliable home environment.
When you invest in a heating system, you are investing in advanced technology designed to optimize your home's climate. The furnace ignitor acts as the catalyst for this process. Instead of burning gas continuously like outdated pilot lights—which wastes energy and drives up seasonal heating bills—the electronic ignitor in a Bryant furnace activates as part of the heating cycle when the system receives a call for heat. This on-demand ignition is a feature of modern gas HVAC systems.
Whether you are planning a major home renovation, booking a furnace replacement, or simply looking to reduce your energy bills, understanding the role of your furnace ignitor empowers you to make smarter decisions about your home comfort system.
How Does A Furnace Ignitor Work?
A Bryant gas furnace equipped with a Hot Surface Ignitor (HSI) uses electrical current to heat the ignitor element until it becomes hot enough to ignite the gas supplied to the burners. Once the ignitor reaches the required temperature, the gas valve opens as part of the furnace's ignition sequence, and the glowing ignitor ignites the gas, creating the flames needed to heat the air circulated throughout your home.
When your smart thermostat detects a drop in indoor temperature, it sends a signal to your furnace to initiate the heating cycle. The furnace control system then coordinates the startup sequence, including the draft inducer, safety checks, ignitor, gas valve, and flame-sensing system. Once the furnace's safety controls allow ignition to proceed, the control board sends voltage to the furnace ignitor.
Bryant currently specifies silicon nitride hot surface ignitors on several gas furnace models. For example, the Bryant 912S and 916S list a silicon nitride PowerHeat™ hot surface igniter, while other Bryant models list a PerfectLight™ hot surface igniter. These ignitors heat rapidly and glow during the ignition sequence. As the gas flows to the burners, the heated ignitor initiates combustion.
The exact electrical specifications, resistance, ignition sequence, and replacement part depend on the furnace model. For that reason, a technician should use the applicable Bryant product documentation when testing or replacing an ignitor rather than relying on one universal voltage, wattage, or resistance specification.
Signs Your Furnace Ignitor Needs Replacement
The most common sign that your furnace ignitor needs replacement is a furnace that blows cold air, fails to ignite the burners, or repeatedly attempts to start without producing heat. A visual furnace inspection may also reveal a crack, break, or other visible damage to the ignitor.
Even the most advanced heating systems require furnace repair. As a homeowner, recognizing the early warning signs of a failing furnace ignitor can save you from an unexpected breakdown during freezing temperatures. Look out for the following indicators:
- No Heat Production: If you hear the furnace begin its startup sequence but the burners do not ignite and only cold air eventually comes out of your vents, a failed ignitor is one possible cause. Other components, including the gas valve, control board, or safety controls, can cause similar symptoms.
- Repeated Startup Attempts: If the furnace repeatedly attempts to ignite the burners but does not establish a flame, the ignitor or another component in the ignition sequence may be malfunctioning.
- Short Cycling: If the furnace turns on, runs for a few seconds, and immediately shuts off (referred to as short cycling), the flame sensor may be detecting that the ignitor failed to start combustion. This safety feature shuts down the system to prevent a dangerous gas buildup.
- Frequent Tripping of the Circuit Breaker: An electrical problem involving the ignitor or another furnace component can trip a circuit breaker. If the breaker repeatedly trips, turn off the furnace and have a qualified HVAC professional diagnose the issue rather than repeatedly resetting it.
- Visible Damage: If you are comfortable visually inspecting the furnace according to the manufacturer's instructions, look for a visible crack or break in the ignitor. Because hot surface ignitors are fragile, do not touch the ignitor element.
How Long Does A Furnace Ignitor Last?
Bryant does not publish one universal service-life or mean-time-between-failure (MTBF) figure for all of its furnace ignitors. Ignitor life can vary depending on the furnace model, ignition system, operating conditions, heating cycles, and other factors. This is why a single lifespan such as “3 to 7 years” or “7 to 10 years” should not be applied to every Bryant furnace.
The longevity of your furnace ignitor is closely tied to the environmental conditions within your home and your routine furnace maintenance schedule. Hot surface ignitors experience repeated heating and cooling cycles, and physical damage or contamination can contribute to premature failure.
Regular professional HVAC maintenance— including gently cleaning the combustion chamber and replacing air filters—ensures superior air filtration and protects the ignitor from damaging buildup. By investing in annual furnace tune-ups, you protect your long-term investment and ensure your furnace continues to operate efficiently year after year.
Learn more about how long a furnace lasts.
Silicon Carbide vs. Silicon Nitride Furnace Ignitors
Hot surface ignitors can be made from different materials, with silicon carbide and silicon nitride among the materials used in furnace ignition systems. Bryant currently specifies silicon nitride hot surface ignitors on several of its gas furnace models.
| Feature | Silicon Carbide | Silicon Nitride |
| Ignition technology | Hot surface ignition | Hot surface ignition |
| Material | Silicon carbide | Silicon nitride |
| Durability | Can be susceptible to cracking from repeated thermal cycling | Designed for durability and resistance to thermal shock |
| Ignition | Heats electrically until it can ignite the gas | Heats electrically until it can ignite the gas |
| Service life | Varies by furnace, component and operating conditions | Varies by furnace, component and operating conditions; Bryant does not publish one universal lifespan |
| Replacement cost | Varies by furnace model, part and labor | Varies by furnace model, part and labor |
Bryant's 912S and 916S gas furnaces, for example, specify silicon nitride PowerHeat™ hot surface igniters. The appropriate replacement ignitor should always be matched to the specific furnace model and approved parts documentation.
Upgrading Your Furnace and Furnace Ignitor
When an old furnace ignitor fails repeatedly, it does not necessarily mean the entire unit needs to be replaced. A qualified HVAC professional can determine whether the ignitor or another component is responsible for the problem. However, if your furnace is older and experiencing multiple component failures or declining performance, replacing the system may be worth considering.
A new Bryant heating system offers smart home integration, allowing you to monitor and control your climate from anywhere with the Bryant Smart Home App. Select Bryant gas furnace models also use electronic hot surface ignition, including silicon nitride ignitors, as part of their burner ignition systems.
Furthermore, new systems are engineered for superior air filtration, meaning you and your family will breathe cleaner air. When evaluating your home renovation plans or responding to a sudden increase in energy bills, choosing an innovative, reliable Bryant system helps ensure you are investing in comfort that lasts. Contact your local Bryant dealer to find the best furnace and learn which ignition system is appropriate for your home.
Furnace Ignitor FAQs
No, a burnt-out furnace ignitor is a common and relatively inexpensive repair. However, if your furnace is over 15 years old and experiencing multiple part failures, upgrading to a new, highly efficient Bryant system may be a more cost-effective long-term investment.
If the furnace ignitor glows but no flames appear, the gas valve may not be opening, the ignitor may not be reaching a high enough temperature, or the flame sensor may be dirty and preventing the cycle from continuing. An expert furnace inspection is required to pinpoint the exact issue.
While it is possible to purchase a replacement furnace ignitor, it is highly recommended to have a certified HVAC professional perform the installation. The ignitor is fragile, and improper installation can damage the component or compromise the safety of your gas heating system.
Yes, silicon nitride ignitors are significantly more durable and energy-efficient than older silicon carbide models. They are highly resistant to cracking from thermal shock and vibrations, making them the preferred choice for long-term reliability in furnaces.
If your furnace won’t start or you hear it click without the burners igniting, a faulty ignitor is a common cause. You may also notice the system blowing cold air or repeatedly trying to start without success.
Replacement typically costs $150 to $4001, including parts and labor, though prices can vary based on the system and service call fees.
A technician will test the ignitor using a multimeter to check for electrical continuity. If there’s no continuity or visible damage like cracks, the ignitor likely needs replacement.
Most furnace ignitors last around 3 to 7 years, depending on usage and system conditions.
Common signs include delayed ignition, no heat, frequent system cycling, visible cracks in the ignitor, or a furnace that tries to start but shuts down quickly.
About The Author: Seth Faber serves as Product Manager for Residential Furnaces at Bryant, where he contributes to the development of heating solutions designed for dependable operation and lasting home comfort. His work takes into account homeowner needs, advances in energy efficiency, and evolving industry standards to help support reliable residential heating.
