Any appliance repair experts out there?

[hemlock]

Our kenmore ovens bottom element quit working yesterday, and I'm having a bit of trouble figuring it out. It shows about 20 Ohms resistance, which indicates that it is still healthy. At the circuit board on the front, the relay that sends power to the element seems to be switching, because there is voltage there as well. On the element itself, with the "bake" element on, I get 120VAC to neutral on either terminal. It seems like power is getting to the element, but it is not heating up. Could the resistance I'm seeing on the element be "false", and a result of something elese in the element. Any help would be appreciated. Thanks.

 

[woodgeek]

First--if you are getting 120VAC across the element (not both to neutral) then the element is shot (open). Disconnect it and measure ohms to confirm.

Personally, I think the problem is more likely upstream. Isolate it and buy a replacement part. I like: http://www.partselect.com/

 

[Don2222]

Hello

Most electric stoves are 240 volts.

Yes, you must remove the element to properly test the resistance. Please try the resulting ohms value with the standard electrical formula below.

E=IR so E/R = I where (E is the Electrical voltage in volts, R is the resistance in Ohms and I is the electrical current in Amps)
So 240v/20ohms = 12 Amps if the bottom element spec is about 12 amps, the Heating Element is Good!

Or

Power=E*I so 240 * 12 = 2420 watts for electrical formulas see http://www.engineeringtoolbox.com/electrical-formulas-d_455.html

The specs in the link below show 2600 watts which is close enough to 2420 watts at 240 volts to mean it is a good element.
http://www.appliancepartspros.com/Appliance-Parts/?keyword=oven+bottom+heating+element

 

[hemlock]

First--if you are getting 120VAC across the element (not both to neutral) then the element is shot (open). Disconnect it and measure ohms to confirm.

Personally, I think the problem is more likely upstream. Isolate it and buy a replacement part. I like: http://www.partselect.com/

Hello.
Across the elements I get nothing. Either terminal to neutral gives me 120VAC. With the element disconnected, I get 20 Ohms.

 

[Later]

Just a guess but if the element reads 20 ohms disconnected and the applied voltage at both terminals is 120 volts it seems as though you are loosing one leg of the 240V that should be there.

 

[woodgeek]

First--if you are getting 120VAC across the element (not both to neutral) then the element is shot (open). Disconnect it and measure ohms to confirm.

Personally, I think the problem is more likely upstream. Isolate it and buy a replacement part. I like: http://www.partselect.com/

Hello.
Across the elements I get nothing. Either terminal to neutral gives me 120VAC. With the element disconnected, I get 20 Ohms.

Ah. As Don said, the element wants 240 VAC, which in normal wiring will be two 120V that are out of phase. That is, in normal operation, both will look like 120VAC to neutral, and 240V relative to each other.

Since the element is 20 Ohms, which sounds correct, the diagnosis is that one of the two ends of the element is not being connected to the line. In this case, both terminals are following each other at 120V--the voltage across the element (as you said) is zero, and so is the power. The problem is upstream of the element. Try the manual or the website I linked above--you will likely just need to replace a board, relay or tstat.

Be safe.

 

[Czech]

Repairclinic.com is good too, in fact just got off the phone with them for a stove ignitor. X2 what wood geek said!

 

[hemlock]

First--if you are getting 120VAC across the element (not both to neutral) then the element is shot (open). Disconnect it and measure ohms to confirm.

Personally, I think the problem is more likely upstream. Isolate it and buy a replacement part. I like: http://www.partselect.com/

Hello.
Across the elements I get nothing. Either terminal to neutral gives me 120VAC. With the element disconnected, I get 20 Ohms.

Ah. As Don said, the element wants 240 VAC, which in normal wiring will be two 120V that are out of phase. That is, in normal operation, both will look like 120VAC to neutral, and 240V relative to each other.

Since the element is 20 Ohms, which sounds correct, the diagnosis is that one of the two ends of the element is not being connected to the line. In this case, both terminals are following each other at 120V--the voltage across the element (as you said) is zero, and so is the power. The problem is upstream of the element. Try the manual or the website I linked above--you will likely just need to replace a board, relay or tstat.

Be safe.

Thanks. Just to be sure - if it was functioning properly, I should see 240VAC across both terminals on the element. The fact that I'm not suggests that there is a "leg" missing, and I'm seeing 0 VAC across the terminals because I'm basically trying to measure across the same line?
From the element, it goes straight to a circuit board with - so it's safe to say I'll be needing a new circuit board?

 

[woodgeek]

Yeah, I think you are getting it. If there is no current flowing, both ends of the element will be the same voltage, but that will be 120VAC relative to neutral. If the circuit board is reasonably cheap and you feel out of your depth, swapping the board is a reasonable thing to 'try' and has a decent chance of success. If it is expensive enough that you will be mad if it still doesn't work, you might want to look deeper.

For example, there should be two 'hots' coming into the board--they will both be 120V to neutral, and 220-240V to each other (b/c of the phase shift). IF the board is getting those two hots in, and not driving the element, I think that is a reasonable smoking gun that you need a new board. If it looks like there are two hots coming in, and one is not 120V to neutral, then the problem is likely upstream of the board....

 

[hemlock]

Yeah, I think you are getting it. If there is no current flowing, both ends of the element will be the same voltage, but that will be 120VAC relative to neutral. If the circuit board is reasonably cheap and you feel out of your depth, swapping the board is a reasonable thing to 'try' and has a decent chance of success. If it is expensive enough that you will be mad if it still doesn't work, you might want to look deeper.

For example, there should be two 'hots' coming into the board--they will both be 120V to neutral, and 220-240V to each other (b/c of the phase shift). IF the board is getting those two hots in, and not driving the element, I think that is a reasonable smoking gun that you need a new board. If it looks like there are two hots coming in, and one is not 120V to neutral, then the problem is likely upstream of the board....

I've got 240VAC on the lines marked L1 and L2 going into the board. I have a strong feeling it is the board (or the SSR for the "bake" element on the board), but just wanted to be certain. A new board is almost $400. Thanks for all the advice/help.

 

[Czech]

Hem, can you post the make and model please? Even a serial? That way us out of work goof balls (yeah, alright, speak for myself!) can poke around.

 

[hemlock]

Hem, can you post the make and model please? Even a serial? That way us out of work goof balls (yeah, alright, speak for myself!) can poke around.

Sure. It is a Kenmore range, Model# C970-445626. It is about 7 years old.

 

[blujacket]

Hem, can you post the make and model please? Even a serial? That way us out of work goof balls (yeah, alright, speak for myself!) can poke around.

Sure. It is a Kenmore range, Model# C970-445626. It is about 7 years old.

invalid model#......recheck model #...pull the drawer out and look on the frame

 

[woodgeek]

L1 and L2 sounds like the two hot lines...

$400! yikes. Is the SSR replaceable separately? What is the # stamped on the SSR??

 

[heat seeker]

For a $400 dollar board, I'd be thinking about a new stove.
The SSR module can probably be replaced for $50 or less, probably just soldered onto the board.

I had to replace the control board in my fridge, it was $100 delivered, has a microprocessor and several relays on it. For a refrigerator, yet!


P.S.
I'm impressed with all the responses to this thread, and they are spot on!

 

[oldspark]

Can you jumper (for test purpose only) the SSR to see if it works then?

 

[willworkforwood]

I don't want to sidetrack this thread, but just wanted to say it's nice to see a bunch of folks who are trying to not be a part of our disposable society. I'm cut from the same cloth - fixed a board into a range a few years ago, and recently TRIED to fix a board on a Fisher-Paykel washer (aka Fisher Price) - sometimes it works, sometimes it doesn't. And this also makes me think about my late brother, who for a short time worked as a TV repairman for Sears 55 years ago. If there's another old timer here, you will remember the days when they actually would come into a home and replace tubes in TVs. I guess we've come a long way since then :roll: .

 

[heat seeker]

I was working on TVs when they still had tubes. The new transistors and the IC's were very confusing at first. They also cut way down of the service calls and parts profits. The local dealers got together and decided to raise all their prices at the same time. I think that was illegal, but they got away with it.
Our best selling tube was a 6GH8, cost $1, sold for $4, plus the service call. We bought those tubes in boxes of 100. 80% of TV troubles were tubes, and the tube testers in the drug stores didn't tell the whole story of a tube, but they could find dead or really weak tubes.
About 2 years ago, I was repairing an old grinding machine at work, and was blown away when I found that it still had tubes in it! They were the black metal industrial type, and no way to test them. The filament was burned out, so it was an easy find.

On topic, I considered repairing the refrigerator board I mentioned earlier, but the only way I could get the relay I needed was to buy 100 of them, at $4 each. A new board was cheaper, but I kept the old one for spares.

 

[oldspark]

When I was a kid I remember the TV repairman coming to the house, he was an important man back in those days, especialy to us kids.

 

[Czech]

There's so much info at our fingertips now, places like here and other specific forums for what ails you. My thought is I'm going to fix it myself or really screw it up before I pay someone else!

 

[hemlock]

There's so much info at our fingertips now, places like here and other specific forums for what ails you. My thought is I'm going to fix it myself or really screw it up before I pay someone else!

That's exactly how I see it.
I'll bet landfills around the globe are filled with equipment and appliances that may only need a $10 part to get it going again, but people now can't be bothered to even look or try to figure it out.

Back to the stove - it's definitely the SSR. It is not closing - there is no voltage at the terminal when there should be. Just for fun, I did what Oldspark suggested and jumpered it, and the element worked fine (burned the tip of my fingers - I'm not that bright sometimes). There is a guy in town who can probably solder a new one on for a pretty good price.

Thanks to everyone here. You helped save me a chunk of money. I hope I can return the favour some time.

 

[woodgeek]

Cool. The SSR is a likely component to fail, soldering a new one seems like a better route than $400.

When you were testing it--did it get the proper input command from the board when you set the oven to on?

 

[hemlock]

Cool. The SSR is a likely component to fail, soldering a new one seems like a better route than $400.

When you were testing it--did it get the proper input command from the board when you set the oven to on?

That is the question that is nagging at me. Suppose the relay does work, and it's just not getting the signal to close? Is there a way to check if the SSR is getting it's signal? I would think I should see a 12VDC input signal somewhere (that is what is on the relay), but I'm not sure where to look.
I do hear a "click" when the button is pressed, but I have a feeling that it is the common relay closing.

 

[blujacket]

Those bake and broil relays fail all the time. I sell a ton of those eoc's.

 

[hemlock]

Those bake and broil relays fail all the time. I sell a ton of those eoc's.

Do they just stick open eventually?