Urinal Keeps Running? Flushometer Checks & Fixes
A urinal that keeps running usually has a flushometer that cannot finish its closing cycle. Debris at a seal, a restricted metering bypass, worn diaphragm or piston parts, or the wrong repair kit are more useful starting points than the drain.
Control the water first. Put the fixture out of service and close its identified control stop gently if trained and authorized. A seized stop or a valve that will not isolate is a plumbing handoff; do not open a pressurized cover.
Identify the flushometer series and the urinal’s specified flush volume before ordering parts. The stop controls supply flow; using it to throttle an unresolved run-on does not repair the internal valve.
Likely causes
- Blocked metering bypass
- Debris under sealing surfaces
- Worn diaphragm or piston assembly
- Incorrect flush-volume kit
- Control-stop issue
| What you observe | What it may mean | Next check |
|---|---|---|
| Continuous flow after handle returns | Valve is not reseating; debris, metering or worn internal parts are possible | Isolate and depressurize before model-specific internal inspection. |
| Problem began after a kit change | Incorrect volume or incompatible assembly | Match fixture and valve specifications to the part number. |
| Several fixtures act abnormally | Shared water-supply conditions may contribute | Compare symptoms and arrange upstream diagnosis. |
| Control stop will not shut off | Safe local isolation is unavailable | Keep the fixture closed to users and arrange plumbing service. |
Tools and preparation
Bring these
- Adjustable wrench
- Screwdriver set
- Shop towels
- Exact model manual and phone for documentation
Before touching anything
- Confirm the exact location and complaint.
- Photograph labels, settings, fault codes, and the original condition.
- Determine whether the failure affects one item or several nearby items.
- Know how to safely isolate the system if the task requires it.
Separate run-on from repeat activation
A continuous flush after the handle returns points toward a valve that is not reseating. Several separate flushes on a sensor model can instead be an activation or setup problem. Watch the whole cycle before taking anything apart.
After isolation and pressure relief, use the exact service drawing to inspect the correct internal assembly. Do not enlarge a bypass hole or mix toilet and urinal kits. On reassembly, restore flow according to the manual and confirm prompt shutoff, effective flushing, no splash and dry joints over several cycles.
For a valve that never starts, follow manual flushometer no-flush checks. For a sensor model, use power, detection and actuator checks.
Step-by-step checks
Identify the valve and flush volume
Identify valve series, fixture requirements, and specified flush volume before choosing an internal kit; a toilet diaphragm is not interchangeable by appearance.
Isolate water and release pressure
Close the identified control stop gently, operate the valve to release pressure, and confirm isolation before removing the cover.
Inspect the correct internal assembly
Follow the exact service drawing to inspect the diaphragm or piston, sealing surfaces, and relief components for grit or damage.
Clean without changing metering
Clean only as the manual permits and never enlarge the metering bypass; replace damaged parts with the exact compatible assembly.
Reassemble and verify shutoff
Reassemble and restore the stop gradually to the prescribed flow. Verify several complete flushes, positive shutoff, no splash, and dry joints before reopening.
Routine fixes that make sense here
- Clean serviceable internal parts
- Replace the correct urinal-specific repair kit
- Restore water slowly and test several flushes
Urinal-specific note
Urinal flushometers often look almost identical to water-closet valves, but the metered volume is different. A wrong-volume internal kit can create long flushes, weak performance, or continuous run-on. Treat the existing valve markings as the starting point for parts identification.
When to stop and hand it off
- Control stop will not close
- Valve body is cracked
- Supply pressure is abnormal across several fixtures
Frequently asked questions
Can I fix it by partly closing the stop?
A stop may limit water loss, but throttling does not prove the internal fault is repaired. Restore the manufacturer’s operating setup after repair.
Can a toilet diaphragm fit a urinal valve?
Similar appearance does not establish compatibility. Match the valve series, fixture application and specified flush volume.
What proves the repair held?
Several complete flushes with positive shutoff, adequate fixture clearing, no splash and no external leaks.
Related BuildingWrench guides
What to document
Record urinal location, valve brand/series, specified flush volume, continuous versus repeated flushing, isolation result, exact kit number and final shutoff/leak-test results.
BuildingWrench provides general educational information for commercial-facility maintenance. Manufacturer instructions, applicable codes, site procedures, and required trade qualifications always take priority.
Tools that fit this task
Use what you already own first. These affiliate links may earn a commission at no extra cost to you. Confirm model and compatibility before buying.
Smooth jaws help protect fittings; verify jaw opening fits the specific fitting.
Use the bit that fully fits the fastener; use hand control for small adjustments.
Dry accessible surfaces so fresh leakage is easier to identify; not for hazardous spill cleanup.