How To Replace Furnace Ignitor? Essential Tips And Tricks


Replacing a furnace ignitor can be overwhelming but, with some guidance, it can be doable. Here’s a step-by-step guide:

  1. Find your furnace’s model number.
  2. Turn off the power.
  3. Remove the old ignitor by unscrewing or unplugging it from the control board.
  4. Securely place the new ignitor in the exact same spot as the old one.
  5. Turn on the power and test for ignition.
  6. Check for any issues that could have caused the old ignitor to malfunction before finishing your repair.
How To Replace Furnace Ignitor?

Remember: Different furnaces need different types of ignitors. Buy one that matches your model.

If you don’t feel comfortable replacing the ignitor, contact an HVAC technician.

When selecting a new ignitor, consider a hot surface ignitor instead of a spark ignitor. Hot surface ignitors don’t need gas flow or an open flame which makes them more reliable. Although the initial cost may be higher, it can save you money in fuel expenses over time.

I once had a cold air issue from my furnace. After inspecting and examining other potential problems with my thermostat and furnace control board, I realized my surface ignitor was defective due to a ceramic crack caused by extreme temperature changes over time. Replacing the old ignitor with a new one immediately solved my problem and restored heat back into my home.

So, get ready to ignite your knowledge about furnace ignitors – it’s about to get hot in here!

What are Furnace Ignitors

Furnace ignitors are key for warming up our homes, but many of us don’t understand them. Spark and Hot Surface Ignitors (HSI) are the two types. A spark ignitor makes a sound and a spark. An HSI lets off a glow to ignite the fuel. If your furnace is blowing cold air, it’s likely the ignitor’s fault. Before replacing, look for cracks or damage.

Before replacing, remember the make and model of your furnace. Get help from a professional if you’re not confident in doing it yourself. To replace an ignitor, switch off the power, remove screws on the front panel, and unplug wires connected to the faulty ignitor or control board socket. Clean the surface, then attach the new ceramic or metal replacement with screws.

My furnace broke down in the middle of winter, at 4 AM! The technician explained HSIs, no open flame needed; it reduces gas and is safer. I learned how important it is to know about furnace parts, for comfort and safety. Replacing a furnace ignitor? Have your tools ready.

Tools Required for Replacing a Furnace Ignitor

Replacing a furnace ignitor can be tricky. You’ll need these five tools:

  1. Ignitor replacement (hot surface or spark)
  2. Emery cloth
  3. Screwdriver (Phillips or flat head, depending on furnace model)
  4. Socket wrench set with extensions, if needed to reach the ignitor
  5. New wire nuts and ceramic wire connectors, as required by the manufacturer

To make the switch, follow these five steps:

  1. Turn off the electrical power to the furnace unit.
  2. Remove the front panel and locate the ignitor.
  3. Replace the old ignitor with a new one, clean metal surfaces with an emery cloth.
  4. Reconnect any wires, using new wire nuts and ceramic wire connectors as instructed.
  5. Reattach the front panel, plug in the furnace, and power it on. You should hear a “click” or see a glow, indicating your hot surface ignition or spark ignition is working.

Remember to note your furnace model number before buying a replacement ignitor. It’s possible to DIY this repair, but it’s safer to get an HVAC technician. To avoid cold nights, have the right tools on hand before any problems arise. Get prepared today!

How To Replace Furnace Ignitor?

Preparing for Ignitor Replacement

When it comes to replacing an ignitor, there are certain steps that need to be followed. Reasons for replacement could be due to normal wear and tear, a crack on the ceramic frame, or faulty components in the furnace control board.

Replacing an ignitor is something that can be done by an HVAC technician or a homeowner with basic repair knowledge. Here is a 6-step guide on how to prepare:

  1. Switch off the power supply to the furnace and locate the gas valve shut-off at the front.
  2. Use a socket to take out the screws that hold the furnace control board in place and disconnect wires from the old ignitor.
  3. Employ emery cloth to clean rust and corrosion from metal surfaces. Check for proper connection points between wires and the new ignitor.
  4. Place the new ignitor in the same spot as the old one and secure it tightly.
  5. Plug back in the disconnected wires and attach the furnace wire covers tightly.
  6. Turn on the power supply to the furnace, increase the temperature with the thermostat, and wait for the orange glow or click sound that indicates spark ignition.

It’s important to note that not all furnaces use spark ignitors, some use hot surface ignition or pilot lights.

When replacing the ignitor, safety gear like gloves and glasses should be worn since dealing with live voltage lines can be dangerous.

If you notice your furnace blowing cold air intermittently, it could mean the ignitor needs to be replaced soon. Follow these steps to get your furnace lit and your house warm!

Replacing Furnace Ignitor

It’s time to put your DIY furnace fixing skills to the test, with the new ignitor! Before doing so, make sure to:

  1. Turn off the power to the furnace – either via the control board or the breaker box.
  2. Disconnect and loosen any wires and screws holding the old ignitor in place. (Be careful – it may still be hot!)
  3. Install the new ignitor with the screws/clips provided, and connect all wires without crossing them.
  4. Once everything is in place, turn the power back on and set the thermostat.

Also, note that some furnaces use spark ignition systems or surface ignitors instead of hot-surface ignition systems. Knowing which one your furnace uses can make the replacement process smoother.

If you’re not confident in replacing the ignitor yourself, hiring a licensed HVAC technician is your best option. And don’t forget to check if your furnace warranty covers the repairs – attempting DIY fixes may void existing warranties.

Testing the New Furnace Ignitor

It’s super important to test a new furnace ignitor before shutting everything up. Here’s the procedure:

  1. First, power off the furnace. This can be done by either flipping the breaker or unplugging it. Safety comes first!
  2. Then, remove and dispose of the old ignitor carefully. In case you need to return the faulty part, make sure not to damage other parts.
  3. Next, install the new ignitor as per the manufacturer’s instructions. Don’t forget to put back the wires disconnected for ignition replacement.
  4. After that, turn on the furnace power at the thermostat and set the temperature higher than the room temperature. The control board should signal for heat.
  5. Observe if the hot surface (HSI) or spark ignition creates an orange/red glow. If this test succeeds, it is capable of heating up– stop once the flame turns on.
  6. Lastly, attach or replace any furnace covers and test the airflow by turning on the blower mode. Check if clean air is being filtered out properly with constant heat signals.

Be careful when dealing with furnaces. If you don’t have professional experience in this field, don’t try handling anything inside them.

Before trying to clean cracks with an Emery Cloth (a type of sandpaper made from large-grained particles of Aluminium oxide), try some other options. It’s mainly used on metal surfaces under delicate operations of repair, as it creates less friction while smoothing out metal surfaces to increase their endurance period. It’s important to note that Emery Cloth is used for highly hazardous work environments involving flammable gases such as Fuel.

Other Troubleshooting Options

If your furnace isn’t working, the issue may not be the ignitor. Here are some other options to think of before replacing it:

  • Check the thermostat: Make sure the temp is correct and that it works.
  • Inspect the gas valve: There must be gas for it to warm up. Check if your valve is open. If there’s still a problem, call an HVAC pro.
  • Look at the furnace control board: This manages the furnace. Check if it’s working properly.

It’s possible these tips will help – but you may still need to replace the ignitor.
Remember to check the manufacturer’s instructions for your model on how to replace it.
Also, you could use a hot surface ignitor instead of a spark ignitor. HSIs glow to ignite the fuel, not create sparks. This can reduce wear and increase safety by reducing the risk of explosions from combustible gases and sparks.
By considering these things, you can avoid costly repairs. Furnace ignitor replacement is made easy – so you don’t get stuck in the cold!


Furnace Ignitor Replacement may seem daunting at first, but with the right tools and method, it’s easy! Here’s a guide:

  1. Turn off the Power: Switch off the breakers/switches in your house. Take precautions when dealing with electricity.
  2. Disconnect Previous Ignitor: Find the burner assembly and disconnect the wires. Check for cracks on the ceramic housing.
  3. Prepare New Ignitor: Clean up metal parts and plug the new ignitor into the socket.
  4. Reconnect Wires: Reattach the wires, securing them with bolts.
  5. Restore Power and Checkout: Switch on all power sources and check if your furnace starts heating.

Hot surface ignitors have a longer lifespan, 5-10 years compared to 2-4 years for spark ignitors. Always double-check who has a bad ignitor before making changes.

Replacing an ignitor typically costs $300-$400 for both parts and labor, depending on factors such as manufacturer, model number, and warranty.