How does an electric stove plate control its heat?
The knob turns a switch that clicks the power to the plate on and off. On a low setting the plate is on for short bursts, on high it stays on. When the switch fails with its contacts stuck closed, the plate gets power without a break, so it runs at full heat on every setting.
Common causes
These are the usual causes, starting with the ones you can check yourself.
At a glance
| Cause | Who fixes it |
|---|---|
| The plate switch contacts are welded shut | Technician |
| A damaged knob or switch spindle | Technician |
| A wiring fault behind the control panel | Technician |
| A fault in the plate itself | Technician |
- 1
The plate switch contacts are welded shut
TechnicianThis is the most common cause. Years of switching wear the contacts until they stick together. The switch must be replaced.
- 2
A damaged knob or switch spindle
TechnicianA cracked knob or a broken spindle can leave the switch turned on even when the knob points to off.
- 3
A wiring fault behind the control panel
TechnicianA burnt or shorted wire can feed power straight to the plate and bypass the switch. Burn marks or a smell of burning plastic are signs.
- 4
A fault in the plate itself
TechnicianSome plates have two heating circuits. If the wrong circuit is fed because of a plate fault, the plate can run hotter than set.
What you can safely check yourself
- Try each settingTurn the knob through each setting and listen. A working switch clicks on and off on lower settings.
- Look at the knobCheck the knob for cracks and make sure it points where you expect.
- Compare platesCheck whether the other plates control normally. If only one is stuck, the fault is usually its own switch.
- Switch off at the isolatorIf the plate will not switch off, turn the stove off at the wall isolator or the breaker.
When to stop and call a technician
A plate will not switch off, stays red hot on a low setting, or you smell burning from the control panel. Switch the stove off at the isolator and do not use it until it has been repaired. Do not open the control panel. The stove runs on a high-current supply.
Still having trouble with your stove?
Our technician comes to your home, usually the same day. The R450 call-out falls away if you go ahead, and you get a fixed price in writing before any work starts.
How a technician diagnoses it
- Isolate the stoveThe technician switches the stove off at the isolator before opening the control panel.
- Switch testThe plate switch is tested for contacts that stick or weld.
- Wiring and plate checkThe wiring behind the panel and the plate are checked for burn damage and faults.
- Fixed priceYou get a fixed price in writing before any part is replaced.
Is it worth repairing?
Usually worth repairing when
- The fault is one plate switch
- The oven and the other plates work well
- The wiring is not badly burnt
Consider replacing when
- Several switches and plates have failed together
- The control panel wiring is badly burnt
- The stove has other major faults as well