Hi
@wannabemammy
Though I don't use this particular pen. It's safe to say all pen mechanism principles are the same..
If the pen jams? Before writing off the actual pen. Carefully change the needle. The new needle could be blocked at the point where it screws into the rubber membrane on the insulin cartridge? This can happen if it gets a "ding" whilst being fitted..?
Next the rubber "bung" in the cartridge that travels up the cartridge that gets pushed by the ram..? This may have seized? Possibly due to dry insulin on the glass cartridge wall causing resistance or sticking? Or even a degedation of tha actual rubber bung..? (I am unfamiliar with the composition of Levemir.)
Perform an "air shoot" vertically (needle to the sky.) to remove trapped air bubbles & "prime" the needle..
By sheer coincidence. You can fire 20 units into the outer white opaque needle cap, which will fill the end level to where the cap starts to flute out. In short, this will tell you the pen is delivering the correct dosage & operating correctly..
If in any doubt? Change the pen.
Hope this helps..