Why Won’t My Furnace Ignite?

No one likes being left out in the cold by their furnace, especially in the dead of winter! If you’re stuck with a gas furnace that keeps clicking but ends up failing to ignite, there are a few troubleshooting steps you can try that won’t cost you a dime and that don’t require the help of a technician. However, some solutions will require a professional for safety’s sake.

There’s a problem with the thermostat.

Typically, your thermostat should be set to AUTO. In this case, you might need to switch it to ON to get the fan going and see if that resolves the issue–just make sure the thermostat is also set to HEAT. If the thermostat displays an error code, it might need to be reset, repaired, or replaced.

The circuit breaker tripped.

Even though gas furnaces burn gas to create heat, most rely on electricity to ignite when they start up. A brief power surge can cause your furnace to trip the breaker of its respective circuit. Check your circuit breaker box to see if the breaker needs to be flipped back into position so that electricity can flow back through your furnace’s circuit.

The gas supply has been shut off.

Your furnace can’t ignite without gas, so check your gas line’s shut-off valve (located outside) to see if it’s open. When performing repairs, a technician will close the valve and might forget to open it, which could be causing your ignition issue. If you’re not sure where the valve is, you can also test your home’s gas supply by seeing if you can ignite your gas stove or another gas-using appliance.

There’s something wrong with the ignition sensor (or thermocouple).

Newer furnaces have an ignition sensor (aka. flame sensor), and older furnaces with a standing pilot light have a thermocouple. These devices are safety features that prevent gas from building up in your furnace.

  • If the ignition sensor detects that the burners haven’t ignited, it shuts off your furnace’s gas supply.
  • Similarly, the thermocouple will shut off the furnace’s gas supply if it can’t detect the pilot light’s heat.

Sometimes the solution is as easy as cleaning the burners or pilot light. However, the repairs get more complex if they involve replacing components or adjusting the composition of the gas-oxygen mixture supplied to your furnace. It’s best to involve a professional technician to get to the root of the issue safely.

For dependable heating repairs and maintenance in Decatur, you can always rely on Jackson Plumbing, Heating & Cooling. Contact us online, or give us a call today:(256) 353-0051.

Flexible Financing options

Learn More
Homepage Image
Homepage Image

Expert Plumbing & HVAC Service in Decatur, AL

Lightning-Fast Service in Madison, Morgan & Limestone Counties

When you need a trusted plumber, HVAC technician, or electrician, turn to Jackson Plumbing, Heating & Cooling—Northern Alabama’s leading home services provider since 1987. With decades of experience, we take pride in delivering expert solutions with reliability, professionalism, and a commitment to our community. Our team understands the importance of dependable service, ensuring every job is done right the first time. Whether it’s a minor repair or a major installation, you can count on us to keep your home running smoothly.

At Jackson Plumbing, Heating & Cooling, your comfort is our top priority. We’re committed to keeping your home’s essential systems running smoothly every day. Homeowners across the Decatur area choose us because we:

  • Have the expertise and equipment to handle any job: Our skilled team is equipped with the latest tools and industry knowledge to tackle any plumbing, heating, cooling, or electrical issue.

  • Maintain professionalism at all times: We follow a strict no-profanity policy and uphold the highest standards of respect and courtesy in every interaction.

  • Prioritize your safety: Every team member undergoes thorough drug testing and background checks for your peace of mind.

  • Are local and always ready to help: As a trusted local business, we’re nearby and ready to respond promptly to your needs.

  • Stay ahead with ongoing training: Our technicians receive continuous training to stay updated on the latest techniques and industry advancements.

  • Offer a Peace of Mind Protection Plan: Our comprehensive service plans keep your systems running efficiently year-round.

At Jackson, we’re more than just a service provider—we’re a team of dedicated professionals committed to delivering quality results at fair and transparent rates.

Contact the Jackson team today to schedule an appointment for plumbing, heating, AC, or electrical services in Madison, Limestone, or Morgan County.

read more