Residential water closets shall not exceed how many gallons per flush?

Residential water closets shall not exceed how many gallons per flush?

• A. 1.0 gpf
• B. 1.25 gpf
• C. 1.6 gpf
• D. 1.75 gpf

Answer: (C)

Water use is limited by a maximum flush volume for residential toilets. The standard sets a ceiling at 1.6 gallons per flush, established to reduce water consumption while still providing effective flushing. That means any residential toilet should not use more than 1.6 gallons per flush. Values at or below that are allowed, while a model using 1.75 gallons would exceed the limit. Some toilets do use less (like 1.0 or 1.25 gpf), but 1.6 gpf is the upper bound defined by regulation.

Water use is limited by a maximum flush volume for residential toilets. The standard sets a ceiling at 1.6 gallons per flush, established to reduce water consumption while still providing effective flushing. That means any residential toilet should not use more than 1.6 gallons per flush. Values at or below that are allowed, while a model using 1.75 gallons would exceed the limit. Some toilets do use less (like 1.0 or 1.25 gpf), but 1.6 gpf is the upper bound defined by regulation.