There are many signs of the clogged drains on which you need to keep your eye. When water drains out slowly through tubs or sinks, water backs into sinks or tubs after flushing the toilet, and sewer water is not able to leave your house; you have clogged drains. Many of you may experience filthy odors or gurgling of the pipes when there is a blockage in the drains. If you notice any of these signs, you need a professional drain cleaning service without batting an eye.