If the water is standing still: Remember, chemical drain cleaners are the enemy. Hydro-jetting is the hero.

Fill a bucket with 2 gallons of water (not from the urinal). Pour it quickly into the bowl. If the water drains away normally, the urinal is fine—your flush valve is broken. If the water backs up or drains slower than a drunk snail, you have a blocked urinal drain downstream.

Few plumbing issues induce as much immediate disgust as walking up to a urinal only to find the bowl filled to the brim with stagnant, foul-smelling water. Whether you are a facilities manager dealing with a high-traffic restroom or a DIY homeowner trying to fix a sluggish ensuite urinal, understanding why blockages happen and how to fix them is essential.