How often do I change the water filter

20.7 cubic feet.

What Are Some Specifications of the Kenmore Coldspot ...

https://www.reference.com > World View
The Kenmore Coldspot 106 is a 20.7-cubic foot side-by-side refrigerator with a reverse osmosis Pur water filter, ice maker and digital controls.

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20.7 cu ft.

What Are Some Specifications of the Kenmore Coldspot ...

https://www.reference.com > World View
The Kenmore Coldspot 106 is a 20.7-cubic foot side-by-side refrigerator with a reverse osmosis Pur water filter, ice maker and digital controls.

There should be a shut off valve inside where the filter goes. When you remove the filter, it should slam shut.

https://www.google.com/search?q=Kenmore+Coldspot+gushes+water+when+changing+the+filter

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The recommended replacement may not be an exact fit.

Hello Margaret, Hello Margaret,
Most likely for this model the water filter is at the base grille of the fridge. It is a Twist on / Twist off.
I have included 3 links that may help you.
Regards,
JP https://www.manualslib.com/manual/85578/Kenmore-106.html#manual
https://www.hunker.com/12569838/where-is-the-kenmore-coldspot-water-filter-located

https://c.shld.net/rpx/i/s/i/spin/image/spin_prod_170910401?hei=444&wid=444&op_sharpen=1

On the front bottom of your unit you have a grill. On the grill there is a round knob. Turn the knob 1/4 turn counter clockwise and pull the filter out. Note the slot on the back of the knob that holds the old filter. Slide the old filter out of the slot and replace with the new filter.
Reinsert the filter with the knob into the filter housing. Turn the knob 1/4 turn clockwise to lock it in.
Now, the new filter has air in it. At your water dispenser, fill cups with water. There will be a lot of air and water coming out. Continue this until all of the air is out of the filter and there is just water fill.
When to change your water filter - Your unit has a water filter change light. This light is not tied into water pressure. It is like a egg timer. Every 6 months it will light. This does not mean you need to change your water filter. Change your water filter when your ice cubes start to get small or the water coming out of your dispenser is of a low flow. Depending on your family size, you may not need to change your water filter for several years.
My name is Peter. I am a retired Sears Home Services refrigeration technician.

If the water filter is old the seals will leak into the evaporative tray overflowing it. Replace the filter or give it a turn to bypass.

The part number is 4392922 for the water filter. You can purchase this water filter at the below link for $ 34.49

http://www.freshwatersystems.com/p-3051-whirlpool-kitchenaid-deluxe-filter-4396510.aspx

FreshWaterSystems
1.877.335.3339
http://www.freshwatersystems.com

Try to search for the solution within the manual: Kenmore Coldspot Model 106 Manual