Despite filters and macerators, fine particles—coffee grounds, eggshell fragments, rice grains, and fibrous vegetable matter—pass into the waste pipe. These particles adhere to the greasy layer, creating a dense, concrete-like composite that resists flushing.
Fats, oils, and grease (FOG) are liquid when hot but solidify as they cool. Inside the waste pipe, hot, greasy water meets the cooler ambient temperature of the pipe, causing FOG to adhere to the inner walls. Over successive cycles, this layer thickens, narrowing the lumen until complete occlusion occurs. blocked dishwasher waste pipe
Diagnosis, Clearance, and Prevention of Blocked Dishwasher Waste Pipes: A Technical Guide Despite filters and macerators