Bosch, Thermador & Gaggenau Gas Range Spark Switch Replacement Guide

If your Bosch, Thermador, or Gaggenau gas range won’t ignite, a faulty spark switch may be the problem. Before calling a technician and paying for expensive repairs, consider replacing the spark switch yourself. This is a common issue and can often be fixed in about an hour with basic tools.

This guide explains the process step by step.

What is a Spark Switch & Why Replace It?

The spark switch sends an electrical signal to the spark module, which then generates the spark needed to ignite the gas.

Over time, spark switches can stop working due to:

• Regular use and wear
• Electrical malfunctions
• Damage from spills, moisture, or harsh cleaning chemicals

Signs of a Faulty Spark Switch

A spark switch may need to be replaced if:

• Burners won’t ignite (turning the knob produces no spark)
• The igniter keeps clicking even after the burner is lit
• No spark is produced when trying to ignite the burner
• The cooktop does not produce a flame despite the gas flow

If any of these problems occur, replacing the spark switch may restore proper function.

Common Causes of Spark Switch Failure

A faulty spark switch can result from several factors. Understanding these causes can help prevent future failures:

• Excessive moisture exposure: Spills, steam, or water from cleaning can seep into the switch, causing malfunctions.
• Frequent use over time: Daily operation leads to natural wear, reducing the switch’s effectiveness.
• Grease and residue buildup: Dirt and cooking residue can interfere with electrical connections.
• Electrical surges: Power fluctuations or surges can burn out internal components.
• Physical damage: Accidental impacts or rough handling during cleaning can break internal parts.
• Wiring issues: Loose or corroded wires can prevent proper electrical flow to the spark module.

To extend the life of a new spark switch, keep the range dry, clean the control panel carefully, and avoid using excessive force when turning knobs.

Tools & Parts Needed

• Replacement Spark Switch (00189008) – Check compatibility with your Bosch, Thermador, or Gaggenau range.
• 13/16-inch socket wrench
• Phillips screwdriver
• Two flathead screwdrivers
• Pliers

Safety Precautions

When working with electrical and gas appliances, follow these precautions:

• Turn off the power: Unplug the appliance or switch off the circuit breaker to prevent electric shock.
• Shut off the gas supply: This prevents potential gas leaks while working.
• Allow the appliance to cool: If the cooktop was recently used, let it cool before handling any parts.
• Work in a dry area: Keep hands and the work surface dry to reduce electrical hazards.
• Keep the workspace clear: Remove clutter, and keep pets and children away.
• Handle wires carefully: Avoid touching exposed wires directly. Use insulated gloves or non-conductive tools.
• Document connections: Take photos or label wires before disconnecting them to simplify reassembly.
• Use gentle force: Applying too much pressure when removing or installing parts can cause damage.

How to Replace the Spark Switch in a Gas Range

Follow these steps to safely replace the spark switch in your Bosch, Thermador, or Gaggenau gas range.

Step 1. Remove the Cooktop

1. Unplug the range from the power outlet.
2. Shut off the gas supply to the range.
3. Lift off the heavy grates from the range surface.
4. Remove any burner caps and heads.
5. Use a 13/16-inch socket wrench to remove the hex nuts holding down each burner base.
6. Carefully lift the burner bases up and out from the range.
7. Pull the entire cooktop gently forward without overextending any wiring connections.
8. Avoid scratching the cooktop surface while lifting.

Step 2. Detach the Control Panel

1. Open the oven door and locate the screws under the front lip of the control panel trim.
2. Remove the screws using a Phillips screwdriver.
3. Pull off all the control knobs from the panel.
4. If your model has a front glass display, remove it.
5. Close the oven door after removing the trim and knobs.
6. Find and remove the screws along the back edge of the control panel.
7. Carefully slide the panel off the range.
8. Disconnect any wiring plugs or terminals on the back side of the panel.
9. Place the control panel on a soft surface.

Step 3. Remove the Old Spark Switch

1. Locate the spark switch for the burner that is not sparking.
2. Use a flathead screwdriver to pry off the small metal clip from the shaft.
3. Use pliers to detach the push-on wire terminals from the back of the faulty switch.
4. Slide the old spark switch off the valve shaft.
5. Discard the old spark switch.

Step 4. Install the New Spark Switch

1. Line up the new spark switch on the valve shaft in the same orientation as the old one.
2. Push the new switch onto the shaft until the clip holes align properly.
3. Reconnect the color-coded wires to the push terminals.
4. Remount the locking clip on the shaft to secure the new switch.

Step 5. Reassemble the Range

1. Position the control panel back over the cooktop element supports.
2. Reconnect any wiring plugs to the control panel.
3. Slide the control panel back into place.
4. Secure the control panel by replacing all the screws along the outer edge.
5. Reinstall the control knobs.
6. If your model has a glass display panel, remount it.
7. Reattach the control panel trim piece and secure it with screws along the bottom oven door lip.
8. Slide the cooktop back into place, making sure no wires or tubes get pinched or snagged underneath.
9. Align the burner bases with their correct pin positions and lower them onto the valves.
10. Thread the mounting nuts back onto the valve stems and tighten them using the socket wrench.
11. Replace all the burner caps, heads, and grates in their proper positions.

Step 6. Restore Power and Test the Burners

1. Turn on the gas supply to the range.
2. Plug the range back into the power outlet.
3. Test each burner by turning the knobs to the ignition position.
4. Verify that all burners ignite and spark correctly.

How to Maintain Your Spark Switch for Longevity

Once a new spark switch is installed, proper maintenance can help extend its lifespan:

• Clean spills immediately: Wipe away any liquid that could seep into the control panel.
• Avoid excessive moisture: Do not use wet sponges or spray cleaners directly on control knobs.
• Turn knobs gently: Forcing knobs can wear out internal components faster.
• Check for buildup regularly: Clean grease and residue from knobs and panel areas.
• Inspect wiring annually: Look for any loose or frayed connections to prevent malfunctions.
• Use a surge protector: This can prevent electrical damage from power fluctuations.

In Summary

Ignoring a faulty spark switch can lead to cooktop problems, and no one wants to struggle with burners that won’t light when it’s time to cook. Replacing it now solves the issue and keeps your range working smoothly for a long time.

If you’ve followed these steps, your burners should be working like new. If they’re still not lighting, check your connections—loose wires often cause problems. If the issue continues, the spark module might need to be replaced instead. Either way, knowing how to fix your gas range saves time and money while keeping you in control of the repair.