Kitchenaid oven heats up all on its own.

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Old 10-16-15, 07:41 PM
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Kitchenaid oven heats up all on its own.

Kitchenaid KDRP407HSS10 dual fuel range -

So tonight my wife went to heat up a lasagna in the oven and almost burnt the house down... *Insert jokes here* She pre-heated the oven to 375 degrees, threw the lasagna in and set the timer for 55 min. At about 30 minutes into cooking the kitchen started to fill with smoke and the lasagna was burnt extra crispy. The oven locked the door and I had to cycle the breaker in order to get the door open. Once open we removed the lasagna, made sure the dial was set to "Reset" (which is our "off" position. As soon as I turned the breaker back on and power went to the oven the coil inside the oven immediately warmed up and turned red hot. And the dial was still on reset. I cycled the dial through all the positions and it was switching through the different modes just like always, but the coil stayed red hot regardless of which position the dial was in.

I flipped the breaker back off and obviously it cooled down again. I tried giving it power once more and same thing... The coil warmed up again in about 15-20 seconds and stayed that way regardless of any input on the controls. So now the breaker is back off and here I am looking for some help. Any info is greatly appreciated!
 
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Old 10-16-15, 07:49 PM
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Welcome to the forums.

Burned lasagna..... oh no.

Does it look like the whole element is heating up or just a portion of it.
If it's the entire element.... that would point to a stuck/burned relay on the control board.
If it's just a part of the element.... that would point to an internally shorted element.
 
  #3  
Old 10-16-15, 07:53 PM
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The entire element is definitely heating up. And it appeared to be heating up evenly.

How would I test for a stuck or burned relay? I have a fairly nice Fluke digital multimeter to test with.


Also I'm curious if it could be the control board as opposed to a relay. Mainly because it heats up even in the reset position. Wouldn't I have to be on the bake position for it to even send power to that relay to begin with? If the "bake" relay was stuck / burnt would it still cause this problem in the "reset" position on the main dial?

And thanks for the quick reply!
 
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Old 10-16-15, 08:09 PM
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I didn't look the unit up yet but usually one side of the element always has power and the other side is switched thru a relay on the control board. The relay gets its command from the controller but if it was stuck on..... it wouldn't make any difference what the control was set to.
 
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Old 10-16-15, 08:21 PM
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I see. That makes sense as to why the switch wouldn't matter. Are the individual relays able to be replaced? Or am I going to have to replace the whole circuit board that houses all the relays? I'm going to pull the top apart in the morning to gain access and start testing. If you get a chance give me some pointers so I know what to look for an where. Like I said I'm not gonna start until tomorrow morning so no rush on a reply.
 
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Old 10-16-15, 08:54 PM
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RepairClinic has some good videos on parts testing. The first place to start is turn the power off to the stove and check both elements. If they are both good then that points you towards the oven relay control module. Unfortunately I can't get a wiring diagram or tech sheet for your stove. There may be one inside by the control section. There may also be a wiring diagram on the back of the stove or on the back of an access door.

KitchenAid Oven Won't Turn Off - Model KDRP407HSS10

This is a picture of the control unit.... although not very helpful. Part # 4452444. The relays in orange and the black one with the two "slide ons" are the ones you are interested in.

Click on picture for larger picture.
 
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Old 10-17-15, 11:21 AM
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Gotcha. So I took the top of the oven apart, and I've accessed that circuit board and see the relays you're talking about. Now I need to figure how to test them.... On the backside of the board I see a bunch of contacts but I don't know where to probe and what I'm testing for. I'm assuming if one of the relays is stuck or burnt it would show continuity between two contacts when there shouldn't be. But I don't know which contacts should and shouldn't have continuity with the power off.....

Again any help is greatly appreciated.
 
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Old 10-17-15, 11:50 AM
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Update -

I unplugged the control board (the part that has the two knobs and digital display) from the main circuit board, flipped on the power and the heating element still got hot all on its own, so that rules that out. I also pulled the heating element out and checked it for continuity (which it had). I checked the two wires that plug into the back prongs on the heating element and no continuity...... That would lead me to believe that something isn't "stuck" or a relay is burnt into position. If it was, wouldn't those two wires be showing continuity all the time? My understanding was that a direct short was purposefully created which caused the element to heat. And when the desired temp was reached it would "un-short" the element and thus stop the heating. Am I correct to assume that the lack of continuity between these wires points to something other than a burnt or stuck relay?
 
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Old 10-17-15, 12:34 PM
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Update again -

So I did some probing around with my meter on the continuity setting and found continuity between two points on the circuit board that seemed kinda odd. I did some more digging and found out that the continuity disappeared when I unplugged one of the molex plugs from the board. Which lead me to believe the possible "stuck" on issue was located somewhere else. I traced that plug to this guy - Name:  IMG_5750.jpg
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I then disconnected one of the blue wires as you can see in the picture. Flipped on the breaker and the heating element did't heat up at all for the first time. Does this help point me in the right direction? And just for info, the continuity is between a green wire (ground, located at bottom left of the picture of the circuit board) and a bunch of other wires on the opposite end of the board. There's continuity between the mentioned ground and the two black wires that feed power into the board, and theres also continuity to all three of the wires to the right of that (a black, an orange, and a grey). For reference on the picture you posted of the board the continuity is between the ground and the slip-on points under the marking "303 3" at the top of the pic, and the three wires in the white 5 wire plug that is under the ".3" mark (there are only 3 wires in the fire wire plug).

Should there be continuity between ground and all of these points? almost all of the points mentioned have to do with the relays located in that area. I understand that each relay needs ground, but it seems like the ground is also connected to the power lines that feed the relays as well.
 

Last edited by Alex72; 10-17-15 at 01:32 PM.
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Old 10-17-15, 01:29 PM
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I wonder if you have a self cleaning feature and if it was accidently set. If so, could it be trying to complete the cycle?
 
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Old 10-17-15, 07:53 PM
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Goldstar is there any way to verify if this is what's happening? I don't think it is simply because when I power the range up I have full control of the dial knob to select any cooking mode I want. If it was trying to re-enter a self clean mode I don't believe I would have the option to select a cooking mode. Also the door doesn't lock as if in a self clean mode.
 
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Old 10-17-15, 11:02 PM
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It's late... I'm tired so not running on all eight here.

Checking the wires that WERE on the heating elements doesn't tell you anything. You need to check each element..... end to end. You should see continuity. Then check from each end to the metal element. You should find no continuity. If the element wiring was touching ground.... you'd trip a breaker.

The orange relays are NO (normally open) relays. They should be each checked and compared to the other two.

Have you found a tech sheet or schematic ? Makes things much easier.

I could use a BIG well lit picture of the back of the board. You can send it to me. You'll find info in a private message.

Here is a similar thread. This shows the detail I can get into. This OP had no heating...... so he had solder problems but the diagnosis and circuit descriptions are similar. Post 16 has a representative schematic. The big black relay controls one leg of the 240v to all elements and each orange supplies the other leg to each element.

http://www.doityourself.com/forum/el...d-working.html
 
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Old 10-20-15, 09:35 PM
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Click on pictures for larger view.





 
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Old 10-20-15, 09:52 PM
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Ok... I marked the board with the three relays.

Measure across the yellow blocks. (convection)
Measure across the red blocks. (bake)
Measure across the blue blocks. (broil)

All three should show open.... no continuity. You'll probably find the bake one shorted. You can pull it out and swap in the convection relay if you need the oven. Post all the numbers on the relay or post a picture here on the board. I'll tell you where to get the relay.


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Last edited by PJmax; 10-20-15 at 10:21 PM.
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Old 10-20-15, 10:16 PM
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I didn't put this on photobucket but this is a closeup of the three orange relays and the big black one. Every solder connection in this picture, basically all the heavy relay and wire connections, needs to be resoldered before they melt. They are in pretty poor shape now. Don't resolder until the defective relay is identified.

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  #16  
Old 10-23-15, 09:04 AM
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So I checked all those points and no continuity across any of them...... So I'm assuming that means they're ok. But I did find out there is continuity across a handful of wires that seems really odd.

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There is continuity between the green wire in the bottom left of the pic (this is a ground wire, that wire is only about 8" long and is held onto the metal body of the oven with a screw). So there's continuity between that green wire and all of the other wires I've marked. But the connection between all of those wires is not a result of the board... I can unplug all the wires from the board and test all the contacts on the board and no continuity. But If I just test the wires themselves (even unplugged from the board) the continuity is there.

So I'm assuming:

1) That there shouldn't be continuity between all of those wires, (maybe I'm wrong on that...)

and

2) Something elsewhere is "stuck" causing that continuity.
 
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Old 10-23-15, 09:11 AM
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I gave you a specific location on the back of the board to check. The wires we are interested in are the blue, red and yellow ones on the black corner plug. Please check the back of the board at the locations I've noted. The colored dots represent the color of the wiring.
 
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Old 10-23-15, 07:24 PM
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Sorry if I wasn't clear, but I did check across the points you said on the back of the board exactly like your picture shows and there is no continuity across them.

My last post was an attempt to explain that, and then also give some additional information.

Sorry if my last post was confusing.
 
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Old 10-23-15, 07:56 PM
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No problem.

Those three orange relays control L1 power to the elements individually.
The black relay supplies L2 to all three elements at the same time.

So in order for an element to heat..... L2 must be on and whichever individual relay that is required for the selected cooking process.

Since you are getting an element heating all by itself, and the relays all show as normally open, the problem must be that the control board is telling the element(s) to turn on.

Make sense ?

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Old 10-23-15, 10:49 PM
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Your explanation on how it works makes sense, I'm following you so far. But how do we determine why / where the control board is doing that?
 
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Old 10-23-15, 11:51 PM
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Just to answer an earlier question.... when you found other wires measuring continuity.

Gray wire - blower
Orange wire - convection fan
Black wire - light power supply.

The wires you were checking were the line side of those devices. They share a common connection to stove neutral which is connected to ground. That would give them continuity to ground.

I'm trying to exhaust all possibilities.
Make one more check for me. If the two red wires can be unplugged from that big black relay next to the three orange ones..... unplug them and see if where they were connected also shows open.

No error codes shown so far.
As this point it looks like a failure of the control board. I've been checking with other techs I know and based on all the relays measuring open it doesn't leave any other choice.
 
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Old 10-24-15, 12:22 AM
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I'm concerned about which board has the problem. The board you were working on is the relay control board. The other board where the buttons are is the oven control board. The oven control board sends commands to the relay board.

I would expect the problem to be on the relay board.

We know the bake element was always on but did you try broil to see if the control board showed broil ?

You could actually activate broil immediately on power up and see what happens. See if the broil element gets hot in addition to the bake element.
 
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Old 10-24-15, 09:27 AM
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I'll check across those where those red wires connect to the relay later tonight when I get home from work. In regards to which control board has the issue I'm leaning towards the board with the relays. The only reason I say that is because one of the first things I tested was unplugging the oven control board (the one with the knobs and digital display) from the relay board. When I did that and powered up the oven it still got hot all on its own, even after being completely unplugged from the relay board.

I'll test that again tonight as well just to be certain.
 
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Old 10-25-15, 11:06 PM
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Update -

So I checked across the terminals on the big black relay where those two red wires slip on (I took the wires off while testing) and they read open. No continuity.

Then I disconnected the oven control board from the relay board and turned the power on. And nothing.... no red hot broil element like the last time I tried this same thing. So then I plugged the oven control board back onto the relay board, fired it all up and.... Everything appears to be working like its supposed to be.... WTF? I was able to set the clock, let it sit and nothing happened on it's own. I could turn the broil on to high and it would heat up, and when I turned the knob back to reset it turned off. I could switch it to bake and set it to 350 and it would heat up (I noticed the broil element got red hot during this but I'm assuming that's to help with the pre-heat, and once the oven hit 350 the broil element cooled down).

So the good news is that it appears to be working. The bad news it that my wife, and to be honest myself too, don't really trust the oven.

Any ideas????
 
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Old 10-25-15, 11:23 PM
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I would say that by disconnecting the power you reset the logic but you had previously turned the breaker off with no effect which rules that idea out.

That leaves a possible loose connection at the connecting cables from the control board to the relay board. Possibly a corroded pin that got cleaned in the unplug re-plug in process.

Other than that..... I'm as baffled as you are.
 
  #26  
Old 10-25-15, 11:29 PM
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Hmmm... Ok, I'll check the connections and look for any corrosion.

I had another thought I wanted to run by you.

What if a relay had stuck just like you thought which caused all my original problems. And when I first unplugged the oven control board from the relay board and turned the power on everything was still messed up because the relay was stuck. But then during all this other testing, (physically removing and messing with the relay control board) I bumped, jolted, or whatever word you want to use, the relay board causing the relay to un-stick. Kind of like when you hit a car starter with a hammer to knock it loose. Which is why once I had the board out and started testing connections they all read fine. And the now that it's all plugged in it's working great again. Or at least until that relay sticks again.

Any thoughts?
 
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Old 10-26-15, 10:48 PM
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Here's the thing. In many stoves a short to ground or a stuck relay will keep an element on. Let me explain.

Look at the drawing. See the orange line I drew in ? That's how many stoves are wired. One end of each element is connected directly to L2. That means there is always 120v on one end of the element. If the element shorts internally to ground you will get 120v flowing thru the element to ground. Also.... if the bake, broil, or convection relay shorts you'll have uncontrolled 240v directly on the element. This is and has been a problem.

Most manufacturers know this and some are taking steps to curb the problem. They've added a double line break relay that opens L2. Yours has that relay. That means there is normally 0v on the elements. So the only way to get power to any element is to have two relays closed..... the line brake and one of the L1 relays. That is almost impossible to happen unless the logic tells two relays to be on.

Theoretically it is possible to have a shorted bake element and a shorted L1 relay but that problem would still be present now. Both shorts wouldn't disappear.

Your stove has a non re-settable thermal safety switch. It's shown just to the right of the L2 label. If the oven heat runs away.... that control will blow open.

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  #28  
Old 10-26-15, 11:16 PM
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I'm following you so far.

When you refer to the "logic" what specifically do you mean when you say the logic would have to tell two relays to be on?

And the process you described referring to how heating elements get activated makes sense, but what does that mean for me and this problem? Is this a "scrap it" and look into a new oven situation? Or is it a replace the relay board situation? Or a replace the oven control board situation?
 
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Old 10-26-15, 11:43 PM
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I would replace the relay board. If you purchase it online get it from one of the places that gives you a 365 day warranty. If it's not the problem you can send it back.

The control board tells the relay board what to do and the relay board processes it. Most of the logic is on the relay board.
 
  #30  
Old 10-29-15, 01:42 PM
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Ok, sounds good. Any recommendation on sites to use to purchase the board?
 
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