Flushometer: Definition & Professional Guide
Call Now (855) 557-9600
A flushometer is a metering valve that delivers a measured volume of water directly from the pressurized supply line to flush a toilet or urinal without using a gravity-fed tank. Flushometers are the standard flushing mechanism in commercial restrooms, schools, hospitals, and public facilities because they recover almost instantly between flushes, support high-traffic use, and require no tank that occupies space or can crack and leak.
Line Pressure, Metered Volume & Diaphragm Valve Operation
A flushometer operates on line pressure rather than the potential energy stored in a tank. When the handle is pressed or the sensor activates, an internal diaphragm or piston valve opens to release a precisely metered volume of water, typically 1.6 gallons for toilets or 1.0 gallon for urinals, meeting current federal water efficiency standards. A relief valve inside the mechanism then gradually closes the main valve, completing the flush cycle in approximately 4 to 8 seconds.
The key advantage of flushometer systems is their recovery time. A tank toilet requires 30 to 60 seconds to refill before it can flush again. A flushometer can flush again almost immediately because it draws from the building’s pressurized water supply, which continuously provides water at 25 to 80 psi. This makes flushometers essential in high-occupancy buildings where multiple rapid flushes are expected.
Flushometers require a minimum water supply pressure of 25 psi and a supply line of at least 1 inch in diameter to function properly. These requirements typically exceed what residential plumbing systems provide, which is why flushometers are uncommon in single-family homes. However, they are occasionally installed in residential settings with adequate water pressure and supply capacity.
Manual, Sensor-Operated, Dual-Flush, Piston & Diaphragm Types
Manual flushometers are activated by pressing or pulling a handle or button. They are the most durable and economical option, requiring no batteries or electrical connections.
Sensor-operated flushometers use infrared sensors to detect user presence and trigger flushing automatically. They improve hygiene by eliminating hand contact and are standard in modern commercial restroom construction.
Dual-flush flushometers offer two volume settings, typically 1.6 and 1.1 gallons, selected by pushing the handle up or down. They meet EPA WaterSense criteria and reduce water consumption in high-use facilities.
Piston flushometers use a piston-style internal valve that is generally more resistant to hard water and debris. They are favored in areas with challenging water quality.
Diaphragm flushometers use a flexible rubber diaphragm to control water flow. They are less expensive than piston models and easier to rebuild but may be more sensitive to water quality issues.
How Flushometer Relates to Plumbing Services
Flushometer installation and repair are primarily commercial plumbing services. Bonded Plumbworks’ commercial plumbing services include flushometer installation, rebuild kits, sensor replacement, and water pressure optimization for commercial restrooms.
When commercial clients report inconsistent flushing, weak flush performance, or continuous running, Bonded Plumbworks diagnoses whether the issue is internal valve failure, insufficient supply pressure, or clogged inlet screens. Many flushometer problems are resolved with rebuild kits rather than full replacement.
ASME A112.19.2, EPAct 1992 & WaterSense Compliance Standards
ASME A112.19.2/CSA B45.1 defines the performance standards for flushometer-valve toilets. The EPAct 1992 federal standard limits toilet flush volume to 1.6 gpf, while EPA WaterSense certifies high-efficiency models at 1.28 gpf or less. The applicable state building codes, Plumbing section, requires flushometer supply lines to be sized per fixture unit calculations to ensure adequate pressure at all points in the system.
Sloan Royal, Zurn AquaVantage, American Standard Selectronic & TOTO EcoPower
Sloan manufactures the Royal and Crown series, the most widely installed flushometers in North America. Zurn produces the AquaVantage series with dual-flush capability. American Standard offers the Selectronic line of sensor-operated flushometers. Toto produces commercial flushometers with EcoPower self-generating turbines that eliminate battery replacement.