Foamy Beer

You need to balance your beer using the volumes of CO2 and the temperature. The temperature should be taken with a calibrated thermometer, and the second pour should be immediately poured into the same room temperature glass as the first (chug or dump first pour). I can tell you without even knowing the volumes of Sweetwater that 5 psi is way too low.

 

From a thread in 2010, Sweetwater v/v is 2.47. At 40 degrees that calls for 12 psi. What does the line look like after it has been sitting for a while - air pockets or solid beer?

 

Pockets in the beer line are indicative of breakout because your pressure is too low. Is your thermometer capable of being calibrated? To see if it is accurate put crushed ice in a glass of water and let it sit for a few minutes. Then take the temp of the water without touching the bottom or sides of the glass. Should be 32. If it isn't, you will need to either calibrate it or add/subtract the difference from 32 to your beer temp. I have no idea what "carbed with the release valve" means. Presumably you purged the keg and reapplied pressure? An instant purge really isn't the solution to over carbing if that's the direction you are trying to go.
You aren't over carbed at 12 anyway so I don't think you need to keep doing things like that. Get an accurate temp, set pressure to 12 for now and leave things alone. A beer system isn't like your car where you can change your speed instantly. It takes time to settle in. Leave it alone for 24 hours and don't open the door.
There is a very slight chance you could have a bad keg (damaged seal) but that is very rare.

 

Start with the thermometer. Address one thing at a time. If you shake the keg can you hear slush in it?

 

That is a matter of preference....what temp do you want your beer to be? If 35 then leave the thermostat alone. If you want it warmer, then dial it back a bit. Then we adjust pressure to achieve balance at that temperature using the v/v and the chart. At 35 you would want around 9.5 lbs. The rule for pressure and temperature is as the temperature goes down so does the pressure.

 

See above. I was editing as you were replying. Set your pressure now and leave it all alone for a day. You can still drink while things are settling in and you should it will get the breakout pockets cleared out of your line.

 

While you are drinking and waiting a day you may want to confirm with Sweetwater what the volumes of CO2 is just to make sure. The reference I had was from micromatic's forum and is 4 years old.

 

...or it may still be overcarbed. Without manual intervention, this will likely take a few days to settle down. Draw a pint or two every day or so, or burp the keg now and then - both will help reduce excess CO2 (I prefer the former). But don't be in a hurry.

 

Based on where your temps are you may have some degree of freezing. Shake the keg - do you hear slush in it? As Mike says over carbing will correct and based on your low temps you might have done a little of that. That incorrect thermometer led me to believe it wasn't a possibility, but it is now with this new information.

 

Raising it for tonight won't show results for a day or two. Before you do that, pull another beer. If you haven't since the waiting game started you probably still had pockets of break out in the line from earlier. If you were over carbed before it will take a few days of waiting and drinking or burping (the keg) to balance out. I'd leave the temp alone and keep waiting.