Almost all dispensing problems are the result of improper temperature, improper pressure, or cleaning/sanitation issues.
Reviewing this checklist should solve most common issues.
Is the keg being stored between 36° - 38° degrees F?
Is the CO2 pressure between 7-10 lbs?
Have the Faucet, beer line, and keg coupler been cleaned (with chemicals specifically manufactured for beer line cleaning) on a regular basis?
Some other common problems and their causes:
WILD BEER: Beer, when drawn, is all foam, or too much foam and not enough liquid beer:
Beer temperature is too warm. If you have a tower set-up, the beer may be too warm in the line. This should only impact the first pour of the day when the beer in the line is warmer.
CO2 pressure is set too high
Faucet in bad, dirty, or worn condition.
Kinks, twists or other obstructions in the beer line. Note: Any agitation in the serving line will cause CO2 to come out of solution.
Beer drawn improperly
Beverage line is too long or inside diameter is too big
CLOUDY BEER: Beer in glass appears hazy, not clear:
Frozen or nearly frozen beer. Your beer may be suffering from Chill Haze. (NOTE: Chill haze happens when a beer is chilled below 35°F and polyphenols like tannins, are cross-linked through weak interactions such as hydrogen bonds to create larger particles. These polyphenols come mostly from your grain bill, but they also come from your hops. Often mistaken for yeast, this haze is temporary and doesn’t affect the flavor. Chill haze completely redissolves as the temperature rises and the bonds break up.)
Beer that has been un-refrigerated for long periods of time
Old beer
Dirty faucet, beer line, and/or keg coupler
Your kegged beer has settled and excess hop material, dead yeast, or other beer adjuncts have accumulated at the bottom of the keg where the dip tube pulls your beverage. Subsequent pours should be clearer if this is the case.
FALSE HEAD: Large soap-like bubbles, head dissolves very quickly:
Dry glassware. Pro-tip: You can ‘wet’ your glass or rinse it with cold water before pouring.
Improper pour. Try pouring at a 45-degree angle in your glass.