So yesterday I had a jam with my PLA and I was able to get it cleared without taking things apart. Today I went to print and my PLA had snapped off (does this happen to everyone?) and I tried heating up the hotend to pull the remainder out. Nope, wouldn't budge.

So I took things apart. The nozzle came right off and the heater block is clean. The upper part and the heat break are jammed up as if the jam is up higher.

What is causing the jams in the heat break?