You may have noticed when attempting to use your Kegerator, the faucet handle is very hard to pull, or may not even want to pull at all. Due to the piston type design of faucets, this is common and there is a simple solution to resolve this problem. When this happens, the faucet needs to be cleaned.
To do this, you will want to make sure beer is not going to flow out. Shut off the CO2 and remove the coupler from the keg. The coupler has a check ball, but may allow some beer to flow back out. Be prepared for a little spillage from beer left in the line.
Next, use your spanner wrench and remove the beer faucet. Again, be prepared for a little bit of spillage from any beer left in the beer line.
Once you have the faucet removed, soak it in warm soapy water for an hour or two. This will clean out all of the crystallized sugar and should allow your faucet to open and close freely again.
It is recommended that you clean your faucet in between kegs to prevent this from happening. It also may happen in between pours depending on the beer. Each beer reacts a little different, so there is not exact timeline to how frequently this may happen.
Perlick makes a faucet that prevents this from happening. These are available on kegerator.com.