[davidjames]

I have a Thermador C30-01 smooth top cooktop. One burner had not been heating up at all, for awhile. Now the other 3 burners just quit and does not heat up at all. When I turn the 4 knobs on, all the red light comes on below the knobs, and the power is on.
Does anyone have any suggestions as to what the problem is?

Thank you.

[denman]

I cannot find any info on the given model number.

Since all 3 elements went out at the same time it sounds like a power problem. On many unit the lights use 120 volts but the elements require the full 240.
Could also be that a wire/connection has burned up or opened.

Try flipping the breaker off/on slowly a couple times, sometimes you can loose half the line without actually tripping the breaker.
If this does nothing, check the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
Be careful as 240 volts is lethal !!!

[davidjames]

Thanks for the info.

I checked the voltage on each hot wire, I am getting 120 at the plug. I took the cooktop apart, there are no loose connections or anything obvious like a burnt wire. There are many wires on each switch and on the ceramic burner assembly. I looked at the wire springs that make up the burners, I do not see any that are broken or burnt.
Is there a way to check if the switch is bad or the burners?
Thanks for your help.

[denman]

You have to check for 240 volts between L1 and L2.

I am assuming you checked the voltage using ground/neutral as the reference.
This is no good as 120 volts from one side of the line can feed through parts in the oven so you see it on both sides.

[davidjames]

It's 240 volts, between L1 and L2

[denman]

I cannot find any info on the given model number so must do some guessing.

It sounds like there is a bad connection/wire going to the elements.
All 3 elements or controls would not burn out at the same time.
Trace the L1 and L2 wires to the elements to see it there is a thermal cut-off in the circuit that would kill the power.

There is a possibility that there is a bad connection in the line that is a high resistance. When you measure the line with no load you will see the 240 volts but when an element starts to draw current all or most of the voltage is dropped across the bad connection.


You can check the elements with a meter using resistance.
Elements may range from 10 to 40 ohms approx.
Also each elemnt may have its own thermal cut-off built into the element.
It is wired in series with the element.