A urinal that does not flush usually has a closed control stop or supply valve, a sensor that is not seeing users or has no power, or a worn or wrong valve kit. Check the stop, then the sensor lens, range and batteries, then the valve parts. If it flushes but does not drain, the clog is in the line.
Is the urinal getting water at all?
Check the two shut-offs first. Zurn's troubleshooting table for its Aquaflush valve starts with "Valve will not operate," and the causes are "Stop valve is closed" and "Supply valve is closed." The stop valve is the control stop where the supply pipe meets the flush valve. The supply valve is the building shut-off feeding the restroom.
A stop that was closed during a repair and never reopened leaves a fixture dead, and it takes seconds to check. Zurn says the stop is opened and closed with the adjusting screw, and that it is not necessary to remove the stop valve cap. Then set it as in how to adjust a flushometer.
What if it is a sensor urinal?
Zurn's sensor troubleshooting guide lists these causes for "Valve will not operate":
- Water supply shut off. Turn it on and check the control stop and supply.
- Sensor range adjustment set too short. Increase the range.
- Expired batteries. Replace them.
- Solenoid problem. Replace the solenoid.
Zurn's battery sensor needs a user to stay in range for a set time before it will flush. The sheet says the sensor gives a main flush "after a user is in range for eight or more seconds," and that the delay "prevents actuation of the flush valve by a person walking past the sensor." So a quick pass at the urinal may do nothing by design.
Also look at the lens and the surfaces nearby. Zurn's connected-valve table lists a dirty lens and "Reflective surface in front of sensor" among causes of a valve that will not operate. For a deeper walk through these, read why a sensor-operated commercial toilet will not flush, since the same logic applies to urinals.
What if it flushes, but only a trickle?
That is a volume problem. Zurn's table for "Insufficient volume of water to adequately siphon fixture" gives three causes:
- 1The stop valve is not open enough.
- 2The wrong kit. Zurn's sensor guide lists a "1.0 gal. urinal kit installed in place of 1.5 gal. urinal kit" as a cause. The kit sets the volume, so it has to match the fixture.
- 3Not enough supply volume or pressure. Zurn says to remove the working parts and open the stop to let water run through the empty valve. If the water supply proves unsatisfactory, "steps should be taken to increase the pressure and/or supply."
Zurn's Z6000 sheet also says a valve that "shuts off too quickly" or is "short flushing" points to a damaged diaphragm, an enlarged bypass orifice or a kit not matched to the fixture. Those take a rebuild kit. Water that will not stop is the opposite problem, covered in why a Sloan flushometer keeps running.
How do you tell if the flush is the problem or the drain?
Watch the bowl. If water enters the urinal at a normal rate and then rises or drains slowly, the flush is working and the drain is not. Urinal lines scale up with uric deposits that narrow the pipe. Why urinal lines clog with uric scale explains it and how it is cleared. Zurn also lists "Lime accumulation on vortex or spreader holes of fixture" as a cause of water splashing out, so mineral buildup can affect the bowl itself.
What should you do before calling a plumber?
- 1Open the control stop and look for a closed supply valve.
- 2On a sensor urinal, clean the lens with mild soap and water, replace the batteries and check the range.
- 3Note the valve model and whether it is a urinal or closet kit, so a repair person brings the right parts.
The wider list of sensor failure modes is in how auto-flush sensors fail.
If those checks do not restore the flush, the diaphragm or piston needs attention. EPA says to inspect those parts "at least annually" and replace worn ones. That job needs the right kit for the model and may need the supply tested, which is where a licensed plumber helps. HQ is licensed and insured and offers free estimates on commercial restroom plumbing.