Kitchenaid KBRS21KDWH01 Proper Defrost Cycle

[baumgrenze]

I would like to know how frequently our KA KBRS21KDWH01 (1996) refrigerator/bottom freezer should defrost and how warm the freezer compartment should get with each cycle.

I can't get Google to tell me this basic information. Instead it wants to sell me parts.

I have a <$20 Elitech RC-5 datalogger. I understand that its sensor is slow to respond because it is buried inside the plastic case to keep all parts as 'waterproof' as possible. I've added 2 zipper snack bags for good measure.

Here's a link to the graph I created temperature in °F vs most of a week between 04/18/17 and 04/25/17.

FreezerTempVsTime_04_17 by baumgrenze, on Flickr

and an embed link if that works

<a data-flickr-embed="true"  href="https://www.flickr.com/photos/77932951@N04/33408740864/in/dateposted-public/" title="FreezerTempVsTime_04_17"><img src="https://c1.staticflickr.com/3/2889/33408740864_7e827a1f0b_t.jpg" width="100" height="56" alt="FreezerTempVsTime_04_17"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

There are once a day excursions to between 10 °F and 15 °F while most of the time the temperature is at or below -5 °F.

Is this freezer working "as designed?"

If so, I'm glad and I hope my wife will be reassured since the fridge is now 'officially of-age' since it has been with us over 21 years.

thanks,

baumgrenze

 

 

 

 

 

[john63]

Looks good to me.

The spikes are defrost cycles.

Place a thermometer in the freezer...center location...check every 4 hours.

The target temp should be 0F to 10F

If an adjustment is made to the freezer temp digital display or dial...allow 4 hours before checking  temperature...repeat as necessary until target temp has been reached.

Repeat with the fresh food compartment...target temp should be around 38F.

[evaappliance]

Looks good to me too !  

[baumgrenze]

Thank you both for the prompt replies.

I gather that perhaps we should set the freezer thermostat (the fridge and the freezer have separate 'thermostats' in the fridge compartment) closer to 'normal' to actually raise the freezer temperature closer to 0 °F.

The RC-5 datalogger appears to work fine if you do not require an instantaneous response to a change in temperature. I'll put it up in the fridge for a week next.

I like the '96 model KA because it is nice and quiet. Ours is an open plan post-and-beam house where the kitchen and living room share a common wall that only rises 6' to a 9.5' ceiling, and the fridge is on that wall.

Thanks again for the reassurance that it is still doing what it should.

baumgrenze

 

 

[Budget Appliance Repair]

-5 in the freezer is perfectly fine, no need to try to get it closer to zero, (that would make the spikes at defrost even warmer).

As long as the refrig is in the 35-38 range also all will be fine.

[Econo Appliance]

Your defrost timer may be running too slow.   Your fridge uses a mechanical defrost timer, which should defrost every 8 hours.   By the graph, it looks like you are only defrosting every 20 hours or so.

I also don't like the 20 degree spikes... unless your datalogger was near the defrost heater,  you shouldn't be seeing spikes like that in your freezer.

Take a look at your defrost timer,  it will have "8 hour" printed on it... should be 8 hours on, 20 minutes defrost. 

 

 

 

What i'm wondering is,  what prompted you to even datalog the defrost cycles?  Are you having defrost issues, leaks, or spoiled food?

Edited April 26, 2017 by Econo Appliance

[Budget Appliance Repair]

I really doubt there is any problem with the defrost timer, most Whirlpool units with an 8 hour defrost timer don't defrost every 8 hours of clock time but 8 hours of compressor run time.

[Koi Guy]

On 4/26/2017 at 6:41 AM, Budget Appliance Repair said:

I really doubt there is any problem with the defrost timer, most Whirlpool units with an 8 hour defrost timer don't defrost every 8 hours of clock time but 8 hours of compressor run time.

Most? I'd say some, and even then very few. Or atleast most of the Whirlpool units I see use a continuous run cycle, not an accumulative cycle. 

[Hiroshi]

you can control that if you install a "flying lead" version...

[baumgrenze]

Thanks again for the input.

I finally made time to log and process the temperature in a hydrator drawer of the fridge. Here's a graph for most of a recent week that shows an average temperature of 38.5 °F.

Graph of temperature vs time.

For good measure, here is how the controls are set in the fridge.

https://www.flickr.com/photos/77932951@N04/shares/Bvp3H9

Please let me know if you see anything wrong.

thanks

baumgrenze