When a sink, toilet, or tub becomes clogged, first try plunging. Bail out most of the water but leave a couple of inches so the plunger can seal tightly around the drain opening. Seal any openings -- such as the overflow openings of a bathroom sink or a tub -- by firmly pressing a wet rag into the opening. When plunging a double-bowl sink, seal the drain hole of the other bowl. If you have a dishwasher, clamp its drain hose tightly before plunging so you won't force water back into the dishwasher.
If plunging doesn't work try using a hand crank auger, dismantling a trap, or forcing pressurized water into the drain. If more than one drain is stopped or runs slowly, take more aggressive steps. If that doesn't solve the problem, you may need to call an LIC Plumbing Construction Co professional sewer service.