Bosch Thermador Gaggenau Gas Cooktop Ignition Plug Assembly Parts — Models & Compatibility

If you've got a Bosch, Thermador, or Gaggenau gas cooktop that clicks but won't light — or worse, doesn't click at all — you're likely dealing with a worn ignition plug assembly. This hub covers the 189324 replacement plug that fits across NGT and NGP series models, the exact part that creates the spark your burners need to ignite.

Is This the Right Part for Your Model?

This ignition plug assembly works across Bosch NGT/NGP cooktop series including NGT935UC/01, NGP936UC/01, NGT745UC/01, and NGT742UC/01 models. Your model number is typically stamped on a metal plate inside the storage drawer or on the frame when you lift the cooktop grates. Match your full model number against the compatibility list — the /01 suffix matters for proper fit.

About This Replacement Part

The ignition plug assembly (part 189324, replaces AP2838563, 00189719, 00413966, PS3440546) is the electrode that creates the spark when you turn your burner knob. Over time, these plugs fail from constant thermal cycling and grease buildup that corrodes the electrode tip. Common failure modes include worn electrodes that no longer spark reliably, issues with the electronic ignition module, or damaged wiring that interrupts the electrical signal. Symptoms you'll notice: gas burners that won't light or stay lit, delayed ignition where gas accumulates before igniting (dangerous), or intermittent sparking that works sometimes but not others. One tech who rebuilt an 18-year-old Jennair cooktop noted the ignition system was the first thing to go after the venturi tube welded itself into place — these high-use components simply wear out.

What You'll Need for Installation

This repair takes 30-60 minutes and requires basic tools: screwdrivers, socket set, adjustable wrench, pliers, nut drivers, and a wrench set. Difficulty level is easy — you're removing the cooktop grates, lifting the burner caps, disconnecting one wire connector, and swapping the plug assembly. The trickiest part is usually getting to the ignition wire connection under the cooktop surface, which may require removing a couple of screws to access the underside.

Compatible Model Series

This ignition plug assembly fits across multiple premium cooktop lines:

• Bosch NGT Series: NGT935UC, NGT936UC, NGT945UC, NGT946UC, NGT732UC, NGT735UC, NGT736UC, NGT742UC, NGT745UC
• Bosch NGP Series: NGP935UC, NGP936UC, NGP945UC, NGP946UC, NGP732UC, NGP735UC, NGP736UC, NGP742UC, NGP745UC
• Thermador & Gaggenau: Multiple professional series cooktops (verify your specific model number)

All listed models use the /01 revision suffix. If your model number shows a different suffix, double-check compatibility before ordering.

Why This Part Fails

Ignition plugs live in a harsh environment — they're constantly exposed to heat, moisture from boil-overs, and grease splatter. The ceramic insulator can crack from thermal shock when cold water hits a hot cooktop. The electrode tip erodes over time from thousands of sparking cycles, eventually leaving too large a gap for the spark to jump. And the wire connection can corrode, especially if you've had liquid spills that seeped under the cooktop surface. One user bought a non-working Thermador PRSE48" dual fuel range cheap off Craigslist — turned out the ignition system was toast, and replacing these plugs brought it back to life for a fraction of what a new range would cost.

Installation Tips

Shut off gas supply at the valve before starting. Disconnect power to the cooktop. Remove grates and burner caps, then locate the ignition plug near each burner head — it's the small ceramic-tipped electrode. The wire connector is usually underneath the cooktop surface, accessed by removing a couple of screws around the burner assembly. Disconnect the old plug, install the new one with the electrode positioned about 1/8" from the burner head, and reconnect the wire. Test each burner before reassembling everything — you should hear a steady click and see a blue spark. If one burner still doesn't light, check that the electrode gap is correct and the wire connection is solid.

Order Your Replacement Part

Part 189324 is priced at $57.99 and ships fast. This is a direct OEM-equivalent replacement that fits the same as your original Bosch, Thermador, or Gaggenau part. Don't let a $60 ignition plug keep you from using a $3,000 cooktop — this is one of the easier repairs you can tackle yourself.