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Sunday, June 19, 2011

Keurig Model B60 Coffee Machine - Broken!

See this update - we give up on new replacement machine.


In a previous post, I had noted our Keurig Model B60 coffee machine had become slow to dispense liquid into the our mug.  I thought this was caused by a plug, but I was mistaken.  It was caused by a failed air pump.

How to test for a clogged cup holder.
Where you put your kcups, water is forced into the kcup from a top needle (in the machine's kcup holder area) that punches a hole in the top of the kcup.  This is where the heated water is forced, under pressure, into the kcup.  There is another needle at the bottom of the kcup holder area, that also punches into the kcup.  This is the drain from the kcup, which is draining coffee from the kcup to your mug.

How the machine works
You place water into a reservoir tank on the left side of the Keurig Mldel B60 Coffee Machine.  There is a water pump that pulls water from the water reservoir tank and pumps it into a water-heater-tank.  Water in the water-heater-tank is always heated - this is so you have a quick response to making your cup of coffee - it's already heated and waiting.  There is a small air-pump that pumps air, under pressure, when you push one of the 'brew' buttons, into the water-heater-tank.  So the water-heater-tank is not only heated,  but when you push 'brew', air is forced by the air pump, into the water-heater-tank.  This pressurizes the water-heater-tank, which forces the hot water in the water-heater-tank out and into the top needle and into your kcup.  Flowing under pressure, it pressurizes your kcup coffee, forcing the hot water into your kcup, then out through the bottom needle and into your mug.

Our Machine - Broken
In the case of our machine, no coffee was flowing out of the kcup.  I thought this was caused by a plugged bottom needle drain, but this was a silly mistake on my part.  If I had taken the time to think about this, I would have realized I could have tested this conclusion by not putting a kcup into the holder, and selecting a brew button.  With no kcup in the holder, the water does not exit through the bottom drain needle; it just exits straight out of the bottom, bypassing the needle drain.  So I could have tested this by not putting a kcup into the holder, and selecting brew.  If water had flowed out the bottom into a mug, then I could have correctly concluded the exit needle was clogged.  When I tried this today, water did not flow out of the bottom, even when it was bypassing the needle drain, so I can conclude the needle exit was not plugged; instead, no water was being delivered to the kcup.  So, either we had no water in the reservoir, or there was a leak, or nothing was pressurizing the water, the pickup line inside the water-heater-tank was plugged, or a line from the water-heater-tank to the kcup was plugged.

I spent a lot of time trying to take this machine apart gracefully without doing any damage.  In my opinion, there is no way to do this without damaging the parts.  It may be that there are some special-designed tools that would allow you to get into the machine without damaging it, but none of us would have these tools, even if they exist. The problem is that there are keyed pieces that slip into holder.  These keyed parts have tabs on them; they will push in, then spring open, so they cannot be pulled out without depressing the tabs.  Without some sort of special tool, you can't get to the inside where the tabs are to depress them, so you are locked out.

I wanted in to see what the problem was
At this point, the machine was worthless.  We may have had a unit still under warranty, but we weren't interested in having our machine going down (and gone) for possibly months.  We would rather just buy a new one.  So, that meant this machine was destined for the trash, and I could tear into it - tabs or not!  So tear into it I did!

What I found

  1. Water is pulled (sucked) from the left-side water-reservoir and pushed into the water-heater-tank by a small water pump.  
  2. Once water is in the water-heater-tank, it is heated.  It is always heated and ready to go whenever you drop a kcup into the holder to make coffee.  This means you don't have to wait while the water for your mug is heated - it's always heated and ready to go.
  3. When you put a new kcup into the holder and close the top, two (2) holes are punched into the kcup: one on the top (water entry), and one on the bottom (coffee exit).
  4. When you press one of the 'brew' buttons, a small air pump is started.  This air pump pushes air into the water-heater-tank, which pressurizes the water-heater-tank.  
  5. Water in the water-heater-tank is forced out of the tank by the air pressure being applied to the water-heater-tank by the air pump.
  6. The water that is forced out of the water-heater-tank flows through a tube, through the entry needle into the kcup, where your coffee is, under pressure.
  7. The water mixes with the ground coffee in the kcup, and becomes coffee.
  8. The coffee flows out of the bottom of the kcup through the exit needle, and down into your mug.

3 comments:

  1. My sister recommended this blog and she was totally right keep up the fantastic work!
    Coffee Equipment

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  2. We've gone through 4 Keurig coffee machines within 5 years. issues, inconsistent dispense of water. did not pull water from reservoir to the heating element. We regularly clean and always use filtered water. We finally went for the Cuisinart they have a longer warranty.

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