We have had our Keurig K cup coffee maker for about 11/2 years now. Like many of your there have been problems here and there with "short cupping" and "no cupping." As of late it was spitting water back into the reservoir faster than the cup. I have tried all sorts of different home remedies that I have found on the internet and all are only temporary at best. I went through the Keurig service center a few days ago and I think I have a solution for most issues.
First take an opened paperclip and clear all three little jets in the needle from the K cup filler. Lust lift out the holder and do the top piercing needle, then take apart the holder and poke clear that needle that pierces the bottom of the cup . Now empty your water reservoir and fill it with 100% white vinegar. Turn on your machine and when ready cycle with no k cup cups into a glass measuring cup at the largest cup size setting. My machine is a little over 11/2 cups when it was cleared of junk. Cycle over and over each time measuring out put (remember to empty measuring cup each time ) till half the reservoir is empty. Now here is the Kicker: leave the vinegar all where it is for 4 hours! It will dissolve the calcium etc. and make it whistle clean. After the time is up, cycle the rest of the vinegar out of the reservoir as far as you can, then run as many fresh water cycles through until the water is pure. It could take two full reservoirs to flush out the sour taste. Do this once a month or more depending on the hardness of your water.
Let me know how this works for you. Mine has been fine for a week now, nice to have a machine I can depend on!
Michael
12/23/2012 Update: A few weeks ago it started spitting again, I tried the same routine but no go. I contacted Keurig and explained what I went through this time and no go. I got through right away to an English speaking woman who was polite and cheerful and worked to please. They agreed to send me a new unit at no charge! I received it and it works perfectly. The new model of the same has a larger reservoir with a flip lid to fill very nice. Also when I registered it I got a BOGO coupon to order K cups on line 2 gets you 2 more for free. It came out to 94 cups under $30 with free shipping. Great deal! I am very pleased with their service.
So I decided to tear the old one apart to see what the issue is. This is a very complex machines with many pumps and several circuit boards very impressive! All the plumbing was squeaky clean and no blockages found, and I tore it down to every last part. I you can not get it to work with a good cleaning it is an electrical or electronics problem so don't waste your time and frustration on the old one. If you have not registered your unit, do so now like you just bought it. They will not ask for a receipt or proof of purchase. I was told I would have to send back the K cup holder removable insert, but when the box came there was no request or provision for this. I am sold on the company and their service. The machine is very impressive construction for the money. Good Luck
Michael
