A residential dishwasher not connected to a kitchen sink has a fixture unit rating of ___________.

A residential dishwasher that is not directly connected to a kitchen sink is typically assigned a fixture unit rating of 2. This rating is part of the plumbing industry's method to estimate demand on a plumbing system, helping to size pipes and design drainage and venting systems effectively.

The rating of 2 indicates a reasonable use level for a fixture like a dishwasher, ensuring that plumbing calculations consider both potential volume and usage frequency. Dishwashers, even when not directly connected to sinks, still require an adequate drainage system, and the fixture unit rating reflects this need.

In contrast, other ratings would imply different levels of demand: a rating of 0 indicates no demand, whereas ratings of 3 and 4 would suggest higher usage and consequently more significant implications for plumbing design. Thus, the rating of 2 is a practical representation of a dishwasher's impact on plumbing, even when independent from sink connections.