I replaced a thermocouple on one of my burners yesterday. Its easy:
Instructions:
1) Turn off the power to the cooker
2) Remove all the removal metalwork to make the cooker lighter (hob grills, griddle plate, burner covers, cooker shelves, drawer etc.)
3) Slide the cooker forward so you can access the back
4) Remove the U shaped cover plate around the gas inlet pipe retained by two screws.
5) Remove the back cover - there are screws at the top (pointing upwards, across the middle and bottom and two holding the safety chains. Don't remove all the screws as some hold and and power connectors to the back plate - these can be left in place.
6) Slide the back plate downwards - it won't come off completely due to the flange behind the gas pipe but this does not matter.
7) Now you can see the underside of the burners.
8) Trace the cable of the thermocouple you want to replace to the tap. Reach through the cables and slide off the connector (its a spade connection)
9) Working from on top remove the two cross head burner retention screws, being careful not to lose the silicon washers.
10) Support the burner as it drops to prevent excessive strain on the feeder pipe.
11) Working from underneath loosen the retaining nut in top of the thermocouple - slide sidewise to remove the unit.
12) Carefully remove the rubber grommet from on top of the thermocouple
13) Place the nut onto the new thermocouple and replace the grommet
14) Slide the new thermocouple into place and tighten the nut.
15) Replace the two screws removed earlier to test for height by temporarily replacing the burner flame guide and cap.
16) If (as mine was) the thermocouple is too high and touches the cast iron burner cap, you may need to adjust the height - I did this by placing a washer on the thermocouple below the burner mounting plate before tightening the nut into place.
17) Tighten up the nut fully. Hold the hex body of the thermocouple with pliers if your have inserted a washer, or it will spin.
18) Reconnect the spade connector to the tap body at the front, coiling any unused cable to prevent shorts. Remember it gets hot in the cable cavity.
19) Replace back panel
20) Test thermocouple
21) Replace U cover over gas pipe
22) Slide cooker back into place
23) Replace iron work
Chris Ayers
August 2016