How to Troubleshoot a Nonworking Top Burner in a Glass Top Stove

ID: 221365

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

Steps:

  1. Turn every burner control off.
  2. WARNING: The heating circuit uses 240 V, so unplug the stove or turn off the breaker before touching the cooktop, burner, wires, or terminals.
  3. Let the glass cooktop and burner element cool completely before opening the stove.
  4. Wear safety glasses and work gloves when handling glass, sheet metal, or the burner element.
  5. Access the underside of the glass cooktop and the affected burner element using the stove service procedure.
  6. Record each wire location so the H1, H2, 1A, 2A, 1B, and 2B leads return to the same places.
  7. Find the two main heating contacts on the end of the burner element.
  8. Label the first heating contact 1A and the second heating contact 2A.
  9. Trace the H1 and H2 wires from the burner switch to the 1A and 2A contacts.
  10. Find the smaller B-side contacts and label them 1B and 2B.
  11. Use this A-side diagram: H1 from switch → 1A → element winding → main thermal limiter → 2A → H2 from switch.
  12. Use this B-side diagram for the 120 V indicator circuit: 2B → hot-surface indicator contact → 1B → hot-surface indicator light.
  13. The burner switch sends H1 and H2 power to the 1A and 2A contacts.
  14. The 240 V heating path starts at 1A, travels through the element winding, loops around the burner, returns through the main limiter, and exits at 2A.
  15. The element heats only when the path from H1 to H2 through 1A and 2A is complete.
  16. A break in the winding, 1A contact, 2A contact, wiring, or main limiter can stop the burner from heating.
  17. Locate the main thermal limiter in series with the heating winding.
  18. The main limiter controls the maximum burner temperature so the element does not get too hot.
  19. When the burner overheats, the limiter contact opens and breaks the H1-to-H2 heating circuit.
  20. The burner stops heating while this contact is open because power cannot pass through 1A and 2A.
  21. A main limiter that stays open when the burner is cold can make the burner appear dead.
  22. Keep the stove unplugged or the breaker turned off.
  23. Disconnect at least one wire from 1A or 2A so the meter reads the burner element instead of the stove wiring.
  24. Set a multimeter to continuity or resistance mode.
  25. Place the meter probes on 1A and 2A.
  26. A continuous resistance path means the winding and main limiter are closed while cold.
  27. An open reading means the winding, terminal connection, or main limiter is open.
  28. If 1A to 2A tests good, troubleshoot the burner switch and H1 and H2 wiring with the stove wiring diagram.
  29. The B-side circuit uses 120 V and is separate from the 240 V heating circuit.
  30. The small limiter contact senses burner heat for the hot-surface indicator light.
  31. When the burner warms enough that the glass could burn skin, the contact moves and completes the circuit from 2B through 1B.
  32. The hot-surface indicator light stays on while the 2B-to-1B circuit is complete.
  33. When the burner cools, the contact snaps back and the light turns off.
  34. Never rely on the hot-surface light as proof that the cooktop is safe to touch, because the indicator circuit can fail.
  35. Keep the element disconnected from power and positioned so you can see the indicator contact and temperature probe.
  36. Set a multimeter to continuity and place the probes on 1B and 2B.
  37. With the element cool, the indicator circuit should be open.
  38. Use a heat gun to warm the temperature probe near the indicator contact.
  39. Keep your hands clear of the hot metal and glass, and do not use an open flame.
  40. Watch or listen for the contact to click over as the meter changes to continuity from 2B to 1B.
  41. Remove heat and let the element cool until the contact snaps back and continuity opens.
  42. If the contact never closes or never opens after cooling, the indicator limiter contact may be faulty.
  43. Do not assume the main thermal limiter is bad just because a heat gun will not make it trip.
  44. The main limiter may open only at a temperature higher than a common heat gun can produce.
  45. Use the cold 1A-to-2A continuity test to identify a heating path that is open when it should be closed.
  46. Treat an open cold heating path as a fault in the element winding, main limiter, or terminal connections.
  47. If the burner does not heat and 1A to 2A reads open when cold, focus on the element winding, main limiter, and terminal connections.
  48. If the burner heats but the hot-surface light does not turn on, focus on the 1B and 2B indicator contact and the indicator-light circuit.
  49. If the hot-surface light stays on after the burner cools, check for a B-side contact stuck closed.
  50. If the A-side and B-side tests both pass, continue troubleshooting the burner switch and wiring before replacing the burner element.
  51. Reconnect every wire to its labeled terminal before restoring power.
  52. Test the burner and hot-surface indicator only after the cooktop is fully secured.
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