573738 Genuine Gas Thermocouple 500mm for Fisher & Paykel Gas Cooktops, F&P Flame Failure Thermocouple

This genuine Fisher & Paykel thermocouple, part 573738, is a 500mm flame failure sensor for F&P gas cooktop burners. Its tip sits in the burner flame and keeps the gas valve open only while the flame is burning. F&P also lists a 500mm thermocouple for the wok burner, 573739, so check which burner you're repairing and match the number on the old thermocouple before ordering 573738.

Gas burner won't stay lit? Test the thermocouple

When the flame heats the thermocouple tip it produces a tiny voltage, enough to hold a magnet in the gas tap open. If the flame goes out, the voltage drops away and the valve shuts off the gas within seconds. As a thermocouple ages, its output weakens. The burner lights fine while you hold the knob in, then goes out as soon as you let go, or it needs to be held for longer and longer before it stays alight. A tip that has been bent away from the flame or coated in spill residue causes the same problem.

Part details

• Genuine Fisher & Paykel part 573738
• Gas thermocouple, 500mm long
• Flame failure safety device for gas cooktop burners
• Wok burner version is a different part, 573739

Fitting a gas thermocouple

In Australia, work on gas appliances must be carried out by a licensed gas fitter. Turn off the gas supply and isolate power to the cooktop before starting. The thermocouple screws into the back of the gas tap and clips beside the burner, so route the new one along the same path without sharp kinks. Test each burner and check for leaks after fitting.

Questions about this part

Can I clean the thermocouple instead of replacing it?

Sometimes. If the tip is coated with spills, a gentle clean with a fine abrasive pad may restore it, and a bent tip can be eased back into the flame. If the burner still won't stay lit after that, the thermocouple has worn out and should be replaced.