Every time we run water in the ground floor bathroom sink the bath plug gurgles. The toliet is slow to drain as now is the bath. Also when we run water downstairs then the toliet on the second floor gurgles and we've seen bubbles from it. No nasty smells. Also when the dishwasher comes on the bath on the first floo gurgles. I think there may be a blockage building or from reading this site a problem with a vent? We have new house only 3 years old. Any help would be appreciated.
