Sometimes a beer will not pour properly (e.g. not at all, foamy, slowly), these are the most likely reasons.
NOTE: with 4 taps available if one beer is not pouring well there is a likely issue and it is best to offer the customer one of the other beers rather then provide a sub par fill, unless you are able to easily rectify the issue.
1. Gas is not turned on. Turn on the gas.
2. Gas is not at the correct pressure, i.e. 8 PSI
3. The gas bottle is empty. Change the gas bottle.
4. Keg is empty. Change the keg.
5. Keg is not cold. Allow enough time to chill the keg down - overnight at minimum. Ensure fridge is set to correct temperature 3 degrees.
6. Squealer / growler is warm / hot. Cool down with cold water, then sanitise and fill as per normal.
7. The keg has been shaken during transport. Let to rest or degas if necessary.
8. The beer is overcarbed to a higher than normal volume by the brewery. Degas the keg.
9. The squealer or growler has not been sufficiently primed with CO2 before filling. Ensure that the squealer is primed for approximately 10 seconds prior to filling.
10. The seal between the bung and the squealer or growler is not tight enough. Ensure that the bung is properly fitted.
11. The coupler is not correctly seated onto the keg. Reseat the coupler.
12. Rubber O rings are missing from the gas bottle or coupler. Make sure O rings have been properly fitted. DO NOT OVER TIGHTEN
13. Ball lock quick disconnects have not been properly fitted. Check and refit if necessary.