LRE30453ST/01 LG Oven Heating to set temp then cooling down

[blogboy816]

Model Number

LRE30453ST/01

Brand

LG

Age

More than 10 years

Hello all, I have an LG LRE30453ST/01 mfg February 2010. It will heat up to the set temp and then stop heating. Visual inspection of the main control board (see attached) doesn't reveal any charred / darkened places that might indicate failure. I tested the temperature sensor (thermistor?) with a multimeter and resistance was good at around 1080-1090.

Not really wanting to throw parts at it and it may be best used at the scrap yard, but wanted to see if anyone might offer some help on here.

Also, I came across this post https://www.applianceblog.com/mainforums/threads/lre30453st-01-lg-range-oven-temperature.69377/ which seems similar and didn't see where and didn't see where it was marked FIXED so I'm wondering if this will have to remain a mystery. Anyway, many thanks in advance for your help!

 

[Jake]

Rick explains how to test the relay board in detail here in this thread:

FIXED - LG Electric Range LSB5682SW does not keep heat

Hi guys, been looking at a few similar threads to try and diagnose the problem. If I set the bake temperature to 375, it takes forever to get to temp. If and when it does, it doesn’t keep the temperature for long. The broil element works fine and is how we have been heating everything lately...

www.applianceblog.com

You model uses the same relay board:

LG 6871W1N012B Pwb(pcb) Assembly,sub (AP4441283) - AppliancePartsPros.com

PWB(PCB) ASSEMBLY,SUB 6871W1N012B / AP4441283 made by LG

click.linksynergy.com

The circuit board in your photo is the main control board, you have a separate relay board that controls the oven heating elements.

That relay board is in the back of the range towards the bottom.

This video gives you the general idea of where it is located:

 

[blogboy816]

@Jake Many thanks and sorry for the delay. Life has been crazy the last 48 hours. I will work through the tutorials you provided and post the results! Again thank you much!

 

[blogboy816]

@Jake So I was able to test the relay board and between bake (on the left) and bake (on the right) I'm getting 10V and from bake (on the left) and L2 I'm getting 10V which I'm guessing means that the relay board is shot?

 

[Jake]

Ok, was the oven ON BAKE when you took those voltage readings?

--->Set the oven to bake and check for 220 Volts AC across BAKE and L2 or DLB-OUT. The terminals are marked on the board. L1 is voltage into the board. then, depending on what's selected, bake or broil, it comes out through the relay and to one side of the element. The L2 voltage goes into the board and comes out the Double Line Break relay OUT and is common for both elements.

Touch one meter lead to BAKE and touch the other to L2 then BAKE. Your meter should indicate 220 Volts AC for both measurements.

 

[blogboy816]

@Jake Yessir. It was powered on and element (top/bake) was glowing hot. Also, as pictured in your diagram above, there is no 'Double Line Break relay OUT' that I can see. Just the BAKE and the L2 and BAKE.

 

[Jake]

Ok, then replace the relay board and that will fix it.

Unplug your range first.

 

[blogboy816]

@Jake Many thanks and will do!

 

[Jake]

Ok, sounds good, let us know how it goes.

 

[blogboy816]

@Jake Okay, so I finally go the relay board in the mail today and replaced the old one with it. End result is the stove is not heating to the set temperature. E.g. set to bake (350°) and initially it was only heating to 225 (per the display). I unplugged and plugged back in and it eventually showed 345. However, when I opened the door it didn't seem that hot so I got an oven thermometer and put in there. When the display reads 310 the thermometer reads 275. Any ideas what might be the problem? Also, I noticed a flickering orange light visible from through the glass cooktop. It looks like it's in the vicinity of the Door Latch motor assy. Not sure if something is going bad there. First thought is perhaps the top heatin element is going/gone bad. on that note, I'm not seeing the broil element. I'm guessing it's below the oven box?

 

[Jake]

Are you getting the proper voltages per that diagram I posted in post #5 with the new relay board?

 

[blogboy816]

@Jake Sorry for the delay - I tested the board (plugged in, set to bake at 350°) and I'm getting 84.5 V per the diagram you posted with the new relay board. (Bake-L2 = 84.5, Bake-Bake = 84.5V).

 

[Jake]

That's very odd, check your main voltage coming into the machine, you should have 220-240 volts.

I'd check for 240 volts coming into the range where the power cord hooks up to. Its usually the two outer terminals on the terminal block where the power cord hooks up to. Middle terminal should be neutral.

Unplug the range first and remove the cover from the power supply terminal block in the back of the range and see if you might have a loose connection too.

Here's a good thread about this:

FIXED - Whirlpool Electric Stove Model WFC150M0EB0 stopped working after being plugged in (Clipped Terminal / Red Connection) PHOTOS INCLUDED

I bought a used Whirlpool Model WFC150M0EB0 because my other stove kept burning the food. I plugged it in. (black, white, red and green wires from plug to stove) It worked fine (the stove top, the clock, etc) but when moving it against the wall, sparks few from outlet and heard a sizzle then...

www.applianceblog.com

 

[blogboy816]

@Jake Okay, so per your instructions I tested the power supply terminal block (first pic) in the back of the range and I'm getting 235V.

The second picture is of a component on the back of the stove that appears to have "rust water" stains below it? Could it be faulty?

Also, there are metal "shavings" in a couple places on the back of the stove (pic 3).

Lastly, I'm still not able to figure out what the "glowing orange" is coming from visible through the cooktop (last pic). Any ideas what that might be?

Thank you in advance for you help!

 

[blogboy816]

@Jake Also, there are no loose connections in the power supply terminal block that I can discern.

 

[Jake]

Yes, it looks like you have multiple problems, that glow I have not seen before either.

At this point its best to Contact LG at (800) 243-0000 to come out to see what's going on.