573739 Genuine Wok Burner Thermocouple 500mm for Fisher & Paykel Gas Cooktops, Flame Failure Safety Thermocouple

Fisher & Paykel part 573739 is a genuine 500mm thermocouple for the wok burner on gas cooktops. It's the flame failure safety device that lets gas keep flowing to the wok burner only while a flame is present. Thermocouple lengths and end fittings vary, and other burners on the same cooktop often use different ones, so compare it with your old part or check the model number and product code first.

Wok burner won't stay lit? Check the thermocouple

A thermocouple sits with its tip in the burner flame. Heat makes it produce a tiny voltage that holds a magnet open in the gas valve. If the flame goes out, the voltage drops and the valve shuts the gas off. When the thermocouple weakens or its tip is damaged, the burner lights while you hold the knob in but goes out as soon as you let go, or cuts out after a few minutes. A dirty tip, a loose connection at the valve or a tip pushed out of the flame can cause the same symptom.

Part details

• Genuine Fisher & Paykel part 573739
• Flame failure thermocouple
• 500mm length
• For the wok burner on Fisher & Paykel gas cooktops

Have it fitted by a licensed gas fitter

In Australia, work on gas safety devices must be done by a licensed gas fitter. They'll isolate the gas and power, route the new thermocouple without sharp bends or kinks, set the tip in the correct position in the flame, and tighten the valve connection firmly without overdoing it. Afterwards, the burner should be leak tested and checked to make sure it stays alight when the knob is released.

Questions about this part

How long should I hold the knob in when lighting?

Hold it in for several seconds after the burner lights, or as your user manual says, so the thermocouple has time to heat up. If the wok burner still goes out after that, with the tip clean and sitting in the flame, the thermocouple is likely worn out.