Is a Flushometer the Same as a Flush Valve? A Detailed Guide

Whether you‘re renovating a bathroom or troubleshooting a commercial toilet, knowing the difference between a flushometer and a flush valve is key. Though they serve a similar purpose, these two flushing mechanisms operate quite differently. This guide will explain exactly what a flushometer is, how it differs from a standard flush valve, and provide tips on installation, repair, and maintenance for optimal performance.

What is a Flushometer?

A flushometer is a type of flush valve that uses water pressure, rather than gravity, to flush toilets and urinals. The flushometer consists of a pressurized control valve connected to the water supply line. When activated, the valve opens for a preset amount of time, allowing a precise volume of water to flow into the fixture and create a powerful siphon effect that evacuates the contents.

Flushometers are commonly found in commercial restrooms because of their durability and water efficiency. Unlike gravity toilet tanks, flushometers have no moving parts other than the valve itself. This makes them less prone to leaks and malfunctions. Flushometers also allow for speedy, high-powered flushing using 1.6 gallons per flush (gpf) or less.

How Does a Flushometer Work?

A flushometer valve uses the building‘s water supply pressure to flush the toilet or urinal. Here‘s a quick rundown of the flushing action:

• User presses the flushometer handle or electronic sensor button
• The control valve opens, allowing water to flow directly into the fixture‘s trapway
• Water flows through the trapway, creating a siphon effect that evacuates waste
• The valve closes after a preset length of time (usually 1-2 seconds)
• The valve re-pressurizes, ending the siphoning action
• Water in the supply line refills the fixture‘s trapway

This process provides a fast, powerful flush using a minimal amount of water. The water volume is precisely controlled by the duration the valve stays open.

Flushometer vs Flush Valve Toilet Tanks

While a flushometer uses water pressure for flushing, a standard flush valve toilet relies on gravity and a tank to flush waste. Here are some key differences:

Toilet Tank

• Stores water in a tank that refills between flushes
• Flapper or canister-style flush valve releases stored water into bowl
• Lever/handle attached to chain or rod lifts flush valve to start flush
• Tank size determines water volume used per flush
• Common tank sizes: 1.6 gpf or more

Flushometer

• No storage tank – flushes directly from water supply line
• Pressurized control valve meters water volume
• Handles and electronic buttons activate valve to flush
• Preset flush volumes as low as 1.1 gpf
• Works independently of tank size

While gravity tanks can use more water, flushometer systems conserve water by delivering controlled, low-flow flushes. They also refill much faster than tank toilets between flushes.

Pros and Cons of Flushometers

Advantages of Flushometers

• Conservation – precision control of water volume used per flush
• Speed – tankless design allows rapid flushing
• Durability – fewer moving parts than tank toilets
• Adjustable – control flow pressure and volume to suit fixtures
• Consistent flush power – does not rely on tank level

Disadvantages of Flushometers

• Higher initial cost than gravity toilets
• Require minimum water pressure to operate correctly
• Not self-cleaning – fixtures may require more manual scrubbing

For high-traffic restrooms where water savings and speed matter, flushometers are usually the better choice despite their higher upfront cost. Their longevity also makes up for the initial investment over time.

How to Install a Flushometer

Ready to upgrade your toilet or urinal with a new flushometer? Here are the basic installation steps:

Supplies Needed:

• Flushometer valve
• Mounting bracket and screws
• Supply line and fittings
• Discharge tube
• Flushometer handle

Installation

1. Turn off the water supply and drain the fixture completely.

2. Mount the flushometer valve to the wall with the bracket.

3. Connect the control stop valve to the water supply line.

4. Attach the discharge tube to the outlet.

5. Open water supply and test for leaks. Tighten any connections if needed.

6. Adjust the valve stem and handle per manufacturer instructions.

7. Activate the flushometer several times to verify proper operation.

Be sure to consult the detailed instructions included with your new flushometer for specifics on aligning, calibrating, and finishing the installation.

Replacing a Flushometer

Flushometers may need replacement if they are leaking, have corrosion buildup, or are simply worn out. Here are the steps for flushometer replacement:

1. Turn off water supply and drain fixture completely.

2. Remove any shrouds, covers, or handles from the flushometer.

3. Loosen and remove the lock nut holding the flushometer to the wall.

4. Detach the tailpiece and discharge tube.

5. Install the new flushometer following the manufacturer‘s instructions.

6. Reattach the tailpiece, tube, and handles. Check for leaks.

7. Turn on water supply and test operation several times, adjusting as needed.

Be sure to clean away any old putty, grease, or grime before installing the new flushometer. Replace any worn outlet gaskets as well.

Troubleshooting Common Flushometer Problems

Flushometers may develop issues, just like any other plumbing fixture. Here are some common troubleshooting tips:

Flushometer runs continuously: The control stop may need adjustment or the diaphragm may be warped. Inspect and replace parts as needed.

Weak or sluggish flush: Low water supply pressure. Check building water pressure. Remove mineral deposits from valves.

Noisy operation: Restricted water flow. Clean valve and filters. Check for kinked hoses.

Leakage: Worn control stop seat washers need replacement. Check and replace valve seat.

Handle won‘t activate flush: Handle may be loose and needs tightening. Also check for obstructions around the piston.

Refer to the flushometer owner‘s manual for specific troubleshooting advice. A plumber can also diagnose and service malfunctioning flushometer valves.

Choosing the Right Flushometer

When selecting a flushometer, consider these key factors:

• Fixture type – toilet, urinal, or specialty fixture? Match valve flow rate to application.

• Water pressure – Flushometers need flowing water pressure (20 psi or more).

• Water savings – Look for EPA WaterSense-approved low-flow models.

• Material – Brass bodies last the longest. Avoid corrodible materials.

• Power options – Choose electric or water-powered as needed.

• ADA compliance – For handicap access, ensure proper handle height.

Your plumbing supplier can help you choose the optimal flushometer model for your bathroom or facility.

Maintaining Your Flushometer

Routine maintenance keeps flushometers working properly. Follow these tips:

• Clean fixtures frequently to prevent mineral buildup.

• Check for leaks and tighten connections as needed.

• Lubricate o-rings and seals with approved grease.

• Replace worn handles, gaskets, diaphragms and seals.

• Have a plumber inspect/adjust pressure and water flow periodically.

• For electronic flushometers, check sensor range and battery life.

Other Types of Toilet Flush Systems

While flushometers and gravity tanks are the most common, here are a few other toilet flush system options:

• Pressure-assisted – Uses pressurized air in a sealed tank to create a strong siphon during flush. More complex and noisy.

• Double flush – Offers a choice of full or partial flush to save water. Requires dual flush handles/buttons.

• Vacuum-assisted – Siphons waste with a vacuum pump located in the tank. Very effective but higher maintenance.

• Macerating – Grinds and pumps away waste instead of siphoning. Works where gravity drainage is not possible.

The right flush system comes down to water efficiency needs, installation factors, and budget. Flushometers offer the best value for high-traffic commercial applications. Understanding the differences in flushing mechanisms allows you to make the optimal choice.