Beer won't carbonate

[guinsu]

I've been having this problem over and over with my kegging. I put a keg in the kegerator and hook it up to a line at 12psi. I check each week and the beer is pouring flat until it has been in for about a month. I just bled off one keg and hooked it back up to the gas line, I could hear it filling so there doesn't seem to be a block. The glass pours out at what seems to be the right rate. I've had this problem with a few kegs. Once they finally carb up everything is fine, if anything they tend to pour a little foamy. Any ideas what could be wrong? I am about to keg another beer and don't want to wait till Christmas to try it since it's been aging for months.

 

[Bobby_M]

It's not completely unreaaonabe. I find set and forget reaches full equilibrium at 3 weeks. If you want to rush it a bit, go 20psi for 48 hours.