How to troubleshoot an issue in an electrical cooktop and separate insert oven

Question

I am looking for a little help. Last night my cooktop and oven lost power and stopped working as I began cooking dinner and I need help troubleshooting so I don't tear my whole kitchen apart unnecessarily.

I checked the breaker panel, and no breakers tripped. I identified the breaker for that circuit, turned it off and on again and no change. Waited for the cooktop to cool and tried turning it on again, no change.

On observation, we noted that when we turned off the cooktop elements, all power was cut to the oven; there isn't even power to run the lcd panel on the front of the oven to tell you the temperature. If you turn the element on, the lcd on the oven comes on, but neither the oven nor cooktop generate heat.

Followed the power from the units back to the panel, and found the following. There is a big black wire which runs from the panel to the oven, then smaller red wires which run from the oven to the cooktop. We had an electrical inspection done just over a year ago when we purchased the house, and it turned up no issues so I am assuming this setup is kosher.

With this background, I am looking for help with next steps. I assume a control board is responsible for this behaviour, but as the issue affects both units I can't tell if it originates in the oven or cooktop. I assume it comes from the cooktop, but not too sure since the power all seems to route through the oven. Is there something I could do to eliminate one as the culprit?

Answer 1

I would first look for poor connections.

when we turned off the cooktop elements, all power was cut to the oven; there isn't even power to run the lcd panel on the front of the oven to tell you the temperature. If you turn the element on, the lcd on the oven comes on, but neither the oven nor cooktop generate heat.

That is absolutely classic "lost connection on one of the hots" behavior. When you turn on the element, it provides enough power (with the element acting as a poor-quality wire between hot phases) to the hot that works with the neutral for the 120V functions such as the oven light and display panel to work, but since there's no 240V connection there's no heat to be had.