JMJ Plumbing helps keep commercial restrooms operating efficiently with professional flush valve and sensor repair services. Sensor and flush valve problems can increase water usage and generate constant restroom complaints. We service and replace flushometers, rebuild internal components, repair leaks and running fixtures, and troubleshoot sensor alignment and power issues. You get reliable flushing performance, fewer maintenance call-backs, and reduced water waste.
Signs You Need Flush Valve or Sensor Service
Flush valves fail in ways that either waste an enormous amount of water quietly or embarrass you in front of customers. Both are worth catching early.
- A fixture that runs continuously — the diaphragm or piston inside the valve is not closing, usually because the relief valve seat is fouled with debris or the rubber has hardened. A single running flushometer can waste more water than the rest of the restroom combined.
- Phantom flushing when no one is there — the sensor is picking up a reflection off a door, a partition, or a light-colored floor, or the range setting is too wide. It also drains batteries fast.
- The sensor will not activate at all — dead batteries, a dirty lens, a failed solenoid, or a control module at the end of its life. On hardwired systems it can also be a transformer or power supply issue.
- A weak flush that does not clear the bowl — the valve is delivering less volume than the fixture needs, from a partially closed control stop, a clogged bypass orifice, or low supply pressure to that restroom group.
- Water spitting from the vacuum breaker — the vacuum breaker on the tailpiece has split or its seal has failed. It sprays the floor and the wall behind the fixture every flush.
- Banging pipes when a fixture shuts off — the valve is closing abruptly against high pressure, and the resulting water hammer stresses joints and hardware throughout that restroom group.
- Leaking at the spud, the tailpiece, or the control stop — the connection gaskets have failed or a corroded stop is weeping. Water tracking behind a wall-hung fixture damages the wall and the floor before anyone notices.
How Sensor Flush Valves Work
A commercial flushometer does not store water the way a residential tank does. It uses line pressure and a pressure-balanced diaphragm or piston to release a measured volume in one burst, then closes itself. On a sensor model, an infrared sensor watches the fixture; when a user steps away, the control module energizes a small solenoid, which unseats the relief valve and starts the flush cycle. That is the entire mechanism, and it means almost every symptom points to one of a handful of parts.
| Symptom | Usual cause | Typical fix |
|---|---|---|
| Runs constantly | Debris or wear on the diaphragm and relief valve | Rebuild kit for the valve |
| Flushes with nobody present | Sensor range set too wide or reflective surface in view | Adjust range or reposition sensor |
| No response at all | Batteries, solenoid, or control module | Replace the failed component |
| Weak or short flush | Control stop closed down, clogged bypass, low pressure | Reset the stop, clean the orifice, check supply pressure |
| Spray from the tailpiece | Failed vacuum breaker | Replace the vacuum breaker assembly |
| Pipe noise on shutoff | High static pressure, no arrestor | Address pressure and add arrestors |
Because the parts are standardized by manufacturer, most valves on a healthy body can be rebuilt rather than replaced, which is faster and keeps the restroom open. Replacement makes sense when the chrome body itself is pitted, the model is obsolete, or you are converting a bank of manual valves to sensor operation.
Our Flush Valve and Sensor Service Process
- Inventory the fixtures — we record manufacturer, model, and flush volume for every valve in the building. Mixed hardware is the norm in older properties and it determines which rebuild kits and sensor modules actually fit.
- Test each fixture individually — we cycle every valve, check the flush volume and bowl clearance, watch for run-on, and verify sensor range and response instead of relying on the complaint list.
- Check supply conditions — control stop position, static pressure, and evidence of water hammer, because a restroom full of weak flushes is often a pressure or stop problem rather than six failed valves.
- Rebuild or replace — we rebuild valves with a sound body and replace the ones that are past it, including sensor modules, solenoids, vacuum breakers, spuds, and gaskets.
- Set sensors and volumes correctly — range is tuned to the actual fixture layout so the valve responds to a user and ignores the door, and flush volume is confirmed against the fixture it is serving.
- Report and schedule — you get a fixture-by-fixture record of what was done and what is aging, so the next round of work can be budgeted and scheduled rather than reacted to.
Flush Valve and Sensor Service Across North Metro Atlanta
JMJ Plumbing has been maintaining commercial restrooms across North Metro Atlanta since 1996, in office buildings, schools, churches, medical offices, restaurants, and retail centers. We serve Acworth, Alpharetta, Canton, Cumming, Dunwoody, Hickory Flat, Holly Springs, Johns Creek, Kennesaw, Marietta, Milton, Roswell, Sandy Springs, Smyrna, and Woodstock, plus the surrounding communities. Because a weak flush and a slow drain look identical to a customer, flush valve work often pairs with toilet and urinal clog service and with commercial drain cleaning when the fixture is clearing but the line is not. Most facilities handle this on a preventative maintenance schedule so an entire restroom group is serviced in one visit.
Flush Valve and Sensor FAQs
Why do our urinals flush by themselves?
Phantom flushing means the infrared sensor is seeing something it reads as a user. A reflective partition, a door swinging in range, bright flooring, or a range setting that is too wide will all do it. Adjusting the sensor range or repositioning the unit usually solves it. If it continues, the control module itself is failing and should be replaced.
How long do flush valve sensor batteries last?
Battery life depends on traffic and how often the sensor is triggered, so a high-use restroom in a busy retail center goes through them much faster than a small office. Most buildings do better replacing batteries on a schedule during a maintenance visit than waiting for fixtures to go dead one at a time in front of customers.
Can flush valves be rebuilt instead of replaced?
Yes, and rebuilding is usually the better option. If the valve body is in good condition, a manufacturer rebuild kit replaces the diaphragm, relief valve, and seals and restores the valve to normal operation. Replacement makes sense when the body is corroded or pitted, the model is obsolete with no parts available, or you are upgrading to sensor operation.
Why is our flush valve running constantly?
The valve is not closing, almost always because grit or a worn diaphragm is holding the relief valve off its seat. It is the single largest source of wasted water in a commercial restroom and it runs day and night. Closing the control stop stops the loss until it can be repaired, and a rebuild kit typically corrects it.
Can we convert manual flush valves to sensor operation?
Usually yes. Most major manufacturers make retrofit sensor kits that mount to an existing valve body, and there are also complete sensor valve replacements. Whether a retrofit fits depends on the make, model, and age of the existing valves, and on whether you want battery powered or hardwired units. We confirm compatibility before ordering anything.
What causes a weak flush that will not clear the bowl?
Most often a control stop that has been turned down, either to quiet a noisy valve or during a previous repair. Other causes include a clogged bypass orifice inside the valve, a worn diaphragm, or low supply pressure to that restroom group. If every fixture on one line is weak, the cause is pressure or the supply, not the valves.
How often should commercial flush valves be serviced?
Most facilities do well inspecting and testing flush valves on a recurring maintenance schedule rather than waiting for failures. High-traffic restrooms in schools, stadiums, and retail centers need attention far more often than a small professional office. Batteries, diaphragms, and vacuum breakers are all wear items with predictable service lives once you track them.
Can you service restrooms without closing them to the public?
Usually we take one fixture at a time so the restroom stays open, and for a full building we work floor by floor. When an entire restroom group needs to be down, that work is scheduled outside your operating hours. Tell us your traffic pattern and we will plan the sequence around it.
Restroom fixtures running, flushing on their own, or not flushing at all? Book flush valve and sensor service online, or call JMJ Plumbing at (770) 966-9654. We are a Georgia Master Plumber licensed and insured company (MP210296) serving North Metro Atlanta since 1996, with 24/7 emergency service when a restroom goes down.