Kenmore Coldspot Warm Fridge/Freezer

[soybon]

Howdy,

I have a Kenmore 106.54682300. Just yesterday I noticed that the temp inside the fridge is barely cool (70F) and the freezer is hardly keeping water frozen. I have pulled the grill and vacuumed the coils, but it doesn't seem to help. I can hear the fan on the freezer side and can barely feel any air coming through the top duct (blue in photo) and feel no air coming into the fridge side. Also, I can see quite a bit of frosting on the panel in the freezer where the red circle is. I'm pretty handy, this is just the first fridge issue I've had to face.

Thanks in advance,

[EthanRanft]

Very likely you have a defrost problem. If you think it’s possible a door was left ajar at some point, you could unplug it and manually defrost it for 24hrs and the frost buildup may not come back. Otherwise if that doesn’t work, then you’ll need to determine which part in the defrost system is causing your problem. Either the heater, defrost thermostat or electronic control

[evaappliance]

do what ethan said , then if after a few days it happens again , the easiest way to check it is while it is still froze up , take the evaporator cover off the back of the freezer , ohm out the defrost thermostat and heating element  . if one shows open it is bad , replace the part and your done.  if they show good it will be your electronic control , it is available but pricey .  it would depend on the overall condition of the refrigerator as to putting the money for the control in it .  

[soybon]

On 8/27/2019 at 9:54 PM, EthanRanft said:

If you think it’s possible a door was left ajar at some point, you could unplug it and manually defrost it for 24hrs

Thanks, I do think its possible, seeing as how I have three young children. After manual defrosting, the temperatures have come down to normal and air flow feels normal. I can see the evaporator through vents in the freezer and can see that its already covered in a layer of frost.

On 8/28/2019 at 8:27 AM, evaappliance said:

take the evaporator cover off the back of the freezer , ohm out the defrost thermostat and heating element  . if one shows open it is bad , replace the part and your done.

Is is normal to see fluffy white frost so soon? I'll continue to monitor and get back to you. Is the thermostat referring to the temp sensor, or a mechanical valve like in a car? If sensor, do you know if this uses a thermocouple or just a thermistor?

 

Thanks for your time.

[evaappliance]

nope ,  not normal,  defrost thermostat is a mechanical switch  that clips to the top of the evaporator .   it turns the heater off if it finishes defrosting before the allotted time .  it is still unclear if you have a defrost issue of a door seal issue , may have to keep a eye on it for a few more days 

[soybon]

4 hours ago, evaappliance said:

nope ,  not normal,  defrost thermostat is a mechanical switch  that clips to the top of the evaporator .   it turns the heater off if it finishes defrosting before the allotted time .  it is still unclear if you have a defrost issue of a door seal issue , may have to keep a eye on it for a few more days 

Thanks, will do. So if I'm understanding correctly, the thermostat should be a normally open thermomechanical switch that closes the heating circuit when evap temp gets too low and pops open when it gets back up to temp, which is why you said it's easier to test when frosted over, because then you can just ohm it out. Alternatively, Can I just check for open circuit while dunking it in ice water? WRT to the heating element, I'm guessing I'd just check for continuity on the + and - cables on both ends of the element?

 

Thanks again.

[EthanRanft]

5 hours ago, soybon said:

Is is normal to see fluffy white frost so soon?

The evaporator will very quickly have a thin layer of frost on it from condensation freezing. So the freezer defrosts periodically, sometimes once or twice a day, to keep from accumulating so much frost that it shuts down the airflow. Which is what was happening to you earlier. So now we’re waiting to see if it’s going to defrost, or that frost is going to keep building up

[evaappliance]

The defrost thermostat is only in the game when the refrigerator is in the defrost cycle, and it is normally closed when it is cold , all it does is open the circuit if the evaporator gets defrosted before the control puts it back into the run cycle. That way it doesn’t make excess or unnecessary heat . 

[soybon]

16 minutes ago, EthanRanft said:

So now we’re waiting to see if it’s going to defrost, or that frost is going to keep building up

Thanks again. It's pretty frosted over, I can already feel that the air flow to fridge is being restricted and the temp is starting to rise. It's been about 36 hours since plugging it back in after a 24 hr defrost. sorry for the goofy image, my image host would only allow me to share if I made it silly...

So this likely means the issue is in the defrost unit which, as I understand it could be the thermostat, the heater element, or the control circuit. I've gone ahead and ordered the thermostat since its $10 on Amazon with 2-day shipping (Ultra Durable W10225581). While I'm in there, I'll perform continuity check on heater element. Once I splice in the termostat, should I feel the heater start to heat pretty much instantly, or does it run on a schedule?

[EthanRanft]

5 minutes ago, soybon said:

Once I splice in the termostat, should I feel the heater start to heat pretty much instantly, or does it run on a schedule?

The control board tells it when to defrost. So it won’t heat until it’s ready to defrost. But I would really suggest doing a continuity test on the thermostat and heater before you do anything. If the thermostat isn’t bad, I don’t suggest just replacing it anyway with a cheap one from Amazon. I’ve heard horrible stories of parts that are supposedly OEM from Amazon. If both test good, then your control board is bad

[evaappliance]

[soybon]

6 minutes ago, EthanRanft said:

But I would really suggest doing a continuity test on the thermostat and heater before you do anything. If the thermostat isn’t bad, I don’t suggest just replacing it anyway with a cheap one from Amazon

Absolutely will follow this advice. Nothing replaces experience. Just so there's no ambiguity, my understanding is that when frozen over, an open circuit (OL) on ohmmeter represents a bad thermostat.

[soybon]

And if I need to replace the thermostat, do you recommend soldering it in or using a wire nut? My impression would be that out of potential moisture concerns a wire nut may promote corrosion.

[soybon]

10 minutes ago, evaappliance said:

bummer for sure.

[EthanRanft]

7 minutes ago, soybon said:

Absolutely will follow this advice. Nothing replaces experience. Just so there's no ambiguity, my understanding is that when frozen over, an open circuit (OL) on ohmmeter represents a bad thermostat.

Yes sir

 

3 minutes ago, soybon said:

And if I need to replace the thermostat, do you recommend soldering it in or using a wire nut? My impression would be that out of potential moisture concerns a wire nut may promote corrosion.

My preference is a crimp on butt connector with silicone in the opening to keep moisture out. Soldering wouldn’t be bad, but you would need to insulate it somehow, and don’t use electrical tape. Heat shrink tubing maybe

[soybon]

4 minutes ago, EthanRanft said:

crimp on butt connector with silicone in the opening

I've got a big tube of silicone grease which has only seen minor use on automotive repairs. Finally a chance to use it some more.

[soybon]

OK, so I  opened the expander access panel and got open line on the thermostat. When I pulled it out, the blue plastic filler plug was popped out and one side disconnected internally. I put in the replacement, even though I couldn’t get it to close in a cup of ice/salt water reading 27F (thermostat is marked as 48-15). I checked continuity on heater element and it’s fine. Does it just take a long time for the thermostat to come to thermal equilibrium? Or did I just get a bad unit?

[Vance R]

The markings on the bi-metal are 48-15. Usually means opens at 48 F  and closes at 48 minus 15 which should be 33 F. Clip it to original spot and let it cool from the tube. May take a few minutes if it is room temp. Unless you have freeze spray, just clip it in place. Let it cool 12 to 24 hours and then force defrost to see if heater comes on.

[evaappliance]

3 hours ago, soybon said:

the blue plastic filler plug was popped out

Sure thing bad defrost thermostat 

[soybon]

Hell yes Gents! I just checked the temp on the heater element. Just kicked on and reading over 400F on my thermocouple. I thank you all for lending your expertise to a plebe like me.