Our three year old Keurig suddenly started to run very slowly and produce only a partial cup of coffee. I tried all of the recommended fixes, even taking the upper check valve out and soaking it in vinegar. Cleaned all the needles and outlets with no success. We bit the bullet and bought a new Keurig and… it ran exactly the same way. I then remembered one person commenting online that there was a problem with her K-cup. I purchased a 12 pack of Green Mountain K-cups, reasoning that since Green Mountain is the parent of Keurig they should know how to make good K-cups. It worked!!! Flow was fast and the quantity of coffee was as expected.
The problem started at the same time we purchased an order of Donut House K-cups online. Same brand that we have used for a couple of years. I believe the paper filter in their K-cups is now more restrictive as there is a large amount of liquid left in the used K-cup. So now we use the same K-cup for two passes on the Keurig. Usually two identical medium size settings work best. Still have to use up over 200 of the faulty Donut House K-cups and when gone no more.
== Problem may be with the K-cup''