The water trap also called water seal is the constant reserve of water, systematically created in the siphon, which blocks odours from the waste water network coming inside the house. Operation of the water trap:
1. Use of the sanitary appliance (basin, sink, shower, bathtub, etc.)
2. The water empties and flows into the pipes
3. A small amount of water is kept in the siphon, forming a natural "buffer" against bad odours