Why is my cooktop shocking me?

August 6, 2008 9:51 AM

My cooktop is shocking me. What's wrong?

Two weeks ago water was spilled on our electric cooktop, leading to a popped circuit breaker and some smoke. I turned it on a few hours later, and the circuit stayed on, but the switch that was spilled on didn't work, and ALL the switches carried an electric shock. A multimeter showed 90-110 volts to ground from any of the switches, OR the entire metal casing underneath the cooktop.

The cooktop repair guys came, ordered a new switch to replace the one that was damaged. It worked, and the repairman couldn't feel the shock, probably due to wearing rubber soles, but I noticed it a few hours later. I called them back, they looked at the stove again, and said the problem had to be at the circuit, and to call an electrician.

The electrician came and said the wire back to the circuit breaker didn't include a ground, and that that would fix the problem. I agree that that's important for safety, but I spoke to an electrical engineer and he said that the stove still shouldn't be putting out that kind of voltage to the stove body. He suggested that I check with an ohmmeter between the unplugged stove's hot wire and the stove body to see if there was resistance. Indeed, there is 1400 ohms of resistance. So am I right to have the stove guys come back and look? Is there something wrong inside the stove?

posted by condour75 to home & garden (4 comments total)

There's definitely a short going to the outer body. The techs may have to take the stove apart to find it, though.
posted by Citrus at 10:11 AM on August 6 [1 favorite]

You've got a leak to ground (or unground in your case :) ), probably from an element but possibly from defective insulation on a wire or a defective switch.

You can probably isolate the problem yourself if you have coil type burners. First test for voltage between the case of the cooktop and a good ground. Either the round hole on a 3 prong outlet or the tap on the sink (if they don't have plastic piping). You'll probably have something like 40 - 70 volts or possibly higher. Then remove the burners one by one testing the voltage each time. When the voltage drops to a few volts you've found the problem circuit. Then install one of the other burners in the sock for the problem circuit. If you still have only a couple volts then your problem is the burner, otherwise it's a problem with the wiring/switch. If removing the burners doesn't fix it then you've got to call someone, it can take quite a bit of time to track this down if it isn't visually apparent what the problem is.

If the former you can just order/buy a new burner, if the latter then ya, you need a technician. Unless the original guys will waive the service call fee for the secondthird trip I'd call someone else.
posted by Mitheral at 10:16 AM on August 6 [1 favorite]

You should have them come back, if only because any electric cooktop that can't handle water being spilled on it has what can only be described as a serious design flaw. I wouldn't mess with it myself at all.
posted by sageleaf at 10:47 AM on August 6

Thanks guys,

Oven guys came back and found the problem, a switch that was shorted out. Had the thing been grounded right in the first place, they would've seen the problem a lot faster. So I think all is well. Thanks guys!
posted by condour75 at 12:37 PM on August 6