How to Troubleshoot Glass Top Stove Burners and Switches

ID: 221364

Description: [youtubevideo|gjC4ubPm2pg]Use this guide to...

Steps:

1. Unplug the range from the wall before removing any panels.
2. If the range is hardwired, shut off the breaker and verify that the controls do not turn on before continuing.
3. Move the range so you can reach the rear panel.
4. Wear work gloves, because the rear-panel edges can be sharp.
5. Use a Phillips screwdriver to remove the screws securing the large rear panel.
6. Lift off the rear panel to expose the backs of the burner switches.
7. Find the switch for the burner that does not heat.
8. Look for L1 and L2 on the switch, which are usually the red and black power wires.
9. L1 and L2 often daisy-chain in and out between burner switches.
10. Look for H1 and H2 on the switch, which are the wires running from the switch to the burner.
11. Look for P2 on the switch, which usually feeds the burner-on indicator light.
12. The backs of smooth-top and coil-burner switches usually use similar terminal labels.
13. Use the H1-to-H2 burner test before replacing anything.
14. Test the switch only if the burner shows continuity.
15. Set a multimeter to ohms, or use continuity mode if the meter also shows resistance.
16. Never measure resistance or continuity on a powered stove circuit.
17. Use terminal labels instead of wire color alone, because colors can vary by model.
18. Pull one H1 or H2 burner wire off the switch terminal for the burner being tested.
19. Use an alligator-clip lead or a multimeter probe to contact the disconnected H wire.
20. Touch the other multimeter probe to the other H wire or its switch terminal.
21. Read the resistance through the burner coil.
22. A smaller 1500 or 1800 watt burner often reads about 40 to 42 ohms.
23. A larger 2000 or 2500 watt burner often reads about 20 ohms.
24. A finite reading near those examples means the burner circuit is likely good.
25. No continuity, OL, or no change on the meter means the burner is bad.
26. Reconnect the H1 or H2 wire you disconnected for the burner test.
27. Pull the L1 and L2 power wires off the switch terminals.
28. Clip or hold one multimeter probe to the L1 terminal on the switch.
29. Touch the other probe to the L2 terminal on the switch.
30. Turn the burner knob to any On position.
31. Read the resistance between L1 and L2.
32. The meter should show the same burner resistance you measured through H1 and H2.
33. An open reading here, after a good H1-to-H2 burner reading, means the switch is bad.
34. Replace the burner if the H1-to-H2 burner test is open.
35. Replace the switch if H1-to-H2 is good but L1-to-L2 is open with the switch on.
36. Do not replace the switch when the burner itself has no continuity.
37. A good L1-to-L2 reading with the switch on means the switch is passing power through the burner circuit.
38. Use this section only after the L1-to-L2 test confirms a bad switch.
39. Pull the knob straight off the front of the faulty switch.
40. Use a Phillips screwdriver to remove the screws behind the knob.
41. Support the switch from the rear as the screws come out, because it can fall through the control panel.
42. Transfer the wires from the old switch to the matching terminals on the new switch.
43. Install the new switch in the same orientation as the other switches.
44. Make sure the switch is not upside down before tightening the screws.
45. Plan at least one hour for burner replacement, especially if this is the first time the cooktop has been opened.
46. Have a helper support the glass cooktop while you work under it.
47. Expect short burner wiring that limits how far the cooktop can lift.
48. Some models have a plug that lets you disconnect and remove the whole cooktop, but many do not.
49. Keep tools off the glass surface and do not drop the cooktop.
50. Glass cooktops are expensive and may be hard to replace on older stoves.
51. Open the oven door to reach the screws under the front edge of the cooktop.
52. Use a Phillips screwdriver to remove the two screws under the front edge, one on each side.
53. Pull the cooktop forward enough to release the front edge.
54. Lift the cooktop carefully with a helper supporting the weight.
55. Do not strain or stretch the burner wires while the cooktop is lifted.
56. Identify the burner that failed the H1-to-H2 continuity test.
57. Take a clear photo of every wire on that burner before disconnecting anything.
58. Record wire colors and terminal labels if the photo is not clear.
59. Look for burner terminal labels such as A1, A2, B1, B2, or 2B.
60. Note any wire that runs to a hot-surface indicator or limiter terminal.
61. Remove only the wires from the bad burner.
62. Compare with a neighboring burner if you need help confirming similar wire locations.
63. Find the brace that holds the burners up against the underside of the glass.
64. Look for the brace screw at the front or rear of the cooktop, depending on the model.
65. Lower the cooktop enough to reach the brace screw without pulling on the wiring.
66. Use a Phillips screwdriver to remove the brace screw.
67. Lift the cooktop to the side so the burners can rest on the brace and be reached.
68. Keep a helper supporting the cooktop while the brace is loose.
69. Confirm that all wires are disconnected from the bad burner.
70. Handle the top of the burner carefully, because the burner material is brittle.
71. Lift the burner off the support brace.
72. The burner simply rests on the brace once its wires and support points are free.
73. Note the numbered positions used by the small spring prongs on the burner brackets.
74. Install the new burner with the spring prongs in the same numbered positions.
75. Align the burner with the ring marked on the glass cooktop.
76. Use this typical power path to compare the live wiring with the stove diagram.
77. A typical heating path is L1 → switch → H1 → burner element and limiters → H2 → switch → L2.
78. P2 on the switch usually feeds the burner-on indicator light.
79. The burner limiter closes when the surface gets hot enough to light the hot-surface indicator.
80. The high-limit limiter stays closed during normal use and opens only if the burner overheats.
81. The high-limit limiter protects the glass when the burner overheats.
82. The limiter probe does not control normal cooking temperature.
83. Reconnect each wire to its original terminal on the burner or switch.
84. Reinstall the burner brace and make sure each burner sits against the glass.
85. Lower the cooktop and reinstall the two front Phillips screws.
86. Reinstall the rear panel before moving the range back into place.
87. Restore power and turn on the repaired burner for a brief test.
88. Keep hands away from the burner and glass during the powered test.
89. Confirm that the burner-on and hot-surface indicator lights behave normally.