electricians--troubleshooting an electric oven element.

[greybeard]

I've had trouble with a 4 yr old Tappan electric oven. I know there have been some problems with the contoller board, but not sure if this is what the problem is. The broiler element stopped working firstabout a month ago--we rarely use it. The display, when you select "broil" comes up, then you choose Hi or Lo. Display stays illuminated on high for a moment, then goes to ---- (four dashes) and no heat. I suspect the controller in this instance but.........

The bake element quit last night, in the middle of cooking supper. I select bake, then the temp on the digital adjustment button. (300--350--400 etc) In this case, the temp stays illuminated, and I can still hear the relay kicking on and off as it always does. On for a few minutes, then off for a few minutes. I think this part of the controller board is still working.

I disconnected the power, pulled the back off so I could get to the element connections. (easier than working up inside the oven IMO) Without disconnecting anything, I plugged it back in.
Volts at each of the terminals show 110v to ground on each side--controls on and controls off. Show zero volts between the 2 terminals--on both bake and broil--whether the controls are on or off.

Disconnected power and the wires and set my digital VOM to OHMs, choosing the lowest setting (200), and got a "zero" on both elements between the two element end connections.
Elements physically look good--no burned spots.


Controller board?
Controller board and elements bad?
Elements bad?

 

[Anonymous]

Remove the element and take an ohm meter to it. If it's got an open short the resistance will be infinite

 

[Kingfisher]

When you turn it on do you get voltage at elements?

 

[greybeard]

Remove the element and take an ohm meter to it. If it's got an open short the resistance will be infinite

What is an "open short"?
I know what an open circuit is (infinite resistance).
I know what a short to ground is.
I'm not familiar with an "open short".

Disconnected power and the wires and set my digital VOM to OHMs, choosing the lowest setting (200), and got a "zero" on both elements between the two element end connections.

When you turn it on do you get voltage at elements?

Volts at each of the terminals show 110v to ground on each side--controls on and controls off. Shows zero volts between the 2 terminals--on both bake and broil--whether the controls are on or off.

 

[Anonymous]

Reading comprehension got me again.

 

[Kingfisher]

If it shows o volts at the elements when on then....there is you trouble. What happens if you change the thermostat levels while checking for voltage at the elements?

 

[greybeard]

If it shows o volts at the elements when on then....there is you trouble. What happens if you change the thermostat levels while checking for voltage at the elements?

Doesn't show zero V at the elements--it shows 110 to ground on each side of each element, (which is correct) but doesn't show 220v between the two connections, even tho I thought it would. I do have 220V across the main bus bar at the oven (accross L1-L2 where the cord connects) and the wall receptacle does of course read 220v between L1-L2 and 110v respective to each leg to gnd.
Possibly the controller is bad, and I only get 110 to the elements---from a single leg--which would acount for no 220v "between" the legs.

Nothing happens when I punch in a different temp setting--no change at all. No voltage drop anywhere.
I now suspect a bad controller and ad broil element, possibly with the bake element still good.
That all retails for about $245---over 1/2 of what I paid for the whole thing new just a few yrs ago.

Lots simpler back when they just used 2 knobs up there. A single 2 pole switch for broil, and a 1 pole switch with rheostat for bake.

Rangetop elements are all working fine.......

 

[Kingfisher]

Another reason I like gAs.....have you googled your trouble? Is there a schematic anywhere? What does it show that the elements require? 220 or 110?

 

[wbvs58]

Sounds strange that the relay/thermostat is kicking on and off when there is no heat from the elements.
Ken

 

[Anonymous]

Try swapping the bake Element with the broil element. Usually they are the same.

 

[greybeard]

Try swapping the bake Element with the broil element. Usually they are the same.

Done put it all back together so wife can cook stovetop dinner. Elements aren't the same tho--broil element is $31 more than the bake element.