A glass top stove burner turning on and off is usually normal: radiant elements hold lower settings by cycling full power on and off rather than running at reduced power. It's a problem when the burner cycles so much on high that the pot won't boil, stays fully on at every setting, or won't come on at all.
Quick diagnosis
| Symptom | Likely cause | First thing to try |
|---|---|---|
| Glows and goes dark on medium or low | Normal cycling | Keep cooking; it's working |
| Cycles off on high with a pot on it | Limiter protecting the glass | Use a flat-bottomed pan that matches the burner size |
| Bright red on every setting | Failed burner switch | Turn it off at the breaker and call |
| No heat on any setting | Failed element, switch or wiring | Check the breaker, then call |
| Only the inner ring of a dual burner heats | Ring selector set wrong or one ring failed | Check the ring setting before anything else |
| Crack in the glass | Damaged cooktop surface | Stop using it and turn off the breaker |
A closer look
How radiant burners hold a setting
On most radiant glass tops, the knob controls a switch that turns the element fully on, then fully off, over and over. A lower setting means shorter on-times and longer off-times. Newer models with touch controls often do the same thing electronically. That's why you see the burner glow and go dark while the pan stays at a steady simmer.
The temperature limiter
Under the glass, most radiant elements have a limiter that cuts power if the glass gets too hot. A warped pan, a pan much smaller than the burner, or an empty pan lets heat build up under the glass, so the limiter clicks the element off even on high. Flat, heavy pans that cover the burner fix most of these.
A failed switch
A switch with contacts stuck together keeps the element fully on no matter where the knob is. That's a safety problem. Turn the burner off at the breaker and don't use it until it's repaired.
Element and wiring
An element that never heats may have burned out, or the switch or a wire connection may have failed. Electric ranges and cooktops run on 240-volt circuits, so leave testing to a technician.
Who runs into this most
People who switched from gas or coil burners and aren't used to radiant cycling, cooks using thin or warped pans, and home canners with large pots. Check your manual before canning on a glass top; many give specific guidance.
Prevention checklist
- •Use flat, smooth-bottomed pans sized to the burner
- •Don't run a burner on high with an empty pan
- •Lift pans instead of sliding them
- •Clean spills once the glass cools, especially sugary ones
Time to call a pro
- •A burner stays bright red at every setting
- •A burner won't heat at all
- •Cycling on high is so heavy that water won't boil with a good pan
- •The glass is cracked, chipped or discolored in a spot
Travis's rule of thumb: On low, cycling is the burner doing its job. On high, check the pan first.
A burner stuck on bright red or a cracked top needs our stove repair page or a call to (832) 552-1615. Thinking about induction instead? First learn why an induction cooktop won't detect a pan.