Repair Library

25 guides

Documents · 80 free PDFs

Toilet Running: Triage and Repair

First identify the equipment: tank-type toilet, diaphragm flushometer, piston flushometer, or sensor flush valve. Tank leaks are usually the flapper or fill valve; flushometer run-on is usually a fouled diaphragm or relief valve. Both are routine repairs with the water isolated.

Drain Problem: Slow, Backing Up, or Smelling

One fixture slow is usually a local trap or branch blockage you can clear. Multiple fixtures slow or backing up points to a main line or vent problem and belongs to a drain contractor. A sewer smell with good flow is usually a dry trap or a failed trap primer.

Commercial Faucet Dripping: Cartridge and Washer Troubleshooting

A faucet that drips after shutoff usually has a worn cartridge, stem washer, seat, seal, or debris preventing a seal. Identify the faucet type before disassembly.

Commercial Faucet Has Low Water Pressure? Check These First

If only one faucet has weak flow, the restriction is usually local. Start with the aerator, then verify the stops are open and inspect supply hoses, inlet screens, and the cartridge before escalating.

Commercial Sink Draining Slowly: A Safe Maintenance Troubleshooting Guide

A slow commercial sink is commonly caused by debris in the strainer, pop-up, tailpiece, P-trap, or nearby branch drain. Start with the easiest removable components and avoid creating a chemical hazard for whoever opens the drain later.

Commercial Sink Water Too Hot: Safe First Checks

Water that is suddenly too hot can come from a failed mixing valve, changed heater setting, point-of-use tempering device, recirculation problem, or faucet cartridge issue. Measure temperature instead of guessing.

Commercial Toilet Keeps Running? How to Troubleshoot a Flushometer

If a commercial toilet will not stop running, close the control stop first. The most common causes are debris in the flushometer, a restricted diaphragm bypass, damaged internal parts, or the wrong repair kit.

Commercial Toilet Leaking at the Base: How to Find the Cause

Water at the base can come from the fixture seal, flushometer connections, supply piping, condensation, or cleaning water. Dry the area and prove the source before pulling the toilet.

Floor Drain Smells Like Sewer Gas: How to Fix the Common Causes

A sewer smell from a little-used floor drain is often a dry trap. Refill the trap first, then investigate trap primers, biofilm, venting, or drainage issues if the odor returns.

Flushometer Handle Leaking: How to Repair the Common Handle Seal

Water around a manual flushometer handle usually points to worn handle seals, a loose assembly, or debris inside the handle cartridge. Isolate the valve before removing it.

Commercial Flushometer Won’t Flush: Beginner Troubleshooting Guide

A manual flushometer that will not flush usually has a closed or restricted control stop, a blocked handle/relief passage, worn internal parts, or insufficient building water pressure. Start with water supply and handle operation before opening the valve.

P-Trap Leaking Under a Commercial Sink: How to Find and Fix the Leak

A leaking sink trap is usually caused by a loose slip joint, crooked washer, cracked nut, damaged tubular piping, or a partial clog that makes joints seep. Dry everything first, then run water and identify the first point that gets wet.

Commercial Sensor Faucet Won’t Turn On: What to Check First

When a commercial sensor faucet will not run, separate the problem into sensing, power, water supply, and solenoid operation. Many easy fixes involve batteries, a dirty sensor window, closed stops, a clogged aerator, or a model-specific reset.

Sensor Flushometer Won’t Flush? Check Power, Sensor, Solenoid & Water

When an automatic flushometer will not flush, work in order: power, sensor detection, actuator or solenoid, then water supply. That sequence prevents unnecessary valve tear-downs and parts swapping.

Commercial Toilet Bowl Water Too High After Flush: What It Usually Means

A bowl that rises unusually high during a flush is more often a drainage problem than a flushometer problem. Stop repeated flushing and clear the restriction first.

Urinal Keeps Running? How to Troubleshoot a Flushometer

A urinal that keeps running usually has a flushometer problem, not a drain problem. Start with the control stop and correct flush volume, then inspect the diaphragm or piston assembly for debris, wear, and restricted metering passages.

Backflow Preventer Discharging Water: What Facility Staff Should Do

Water coming from a reduced-pressure backflow assembly needs investigation. A discharge opening performs a protective function; closing that opening is not a repair.

Bottle Filler Low Flow or Filter Light: Identify Before Replacing

A filter indicator and a weak stream may be related, but a light alone does not prove a clog. Record the exact fountain or bottle-filler model before ordering a cartridge.

Banging Water Pipes After a Fixture Closes: First Checks

A bang at the end of a flush or faucet cycle may be a pressure transient or movement in poorly supported piping. Do not assume an arrestor alone solves every noise.

Commercial Plumbing Leak: Find the Source and Limit Damage

A puddle is a symptom, not a diagnosis. First separate a supply leak from a drain leak or condensation, then isolate only the service you can positively identify.

Create a Commercial Domestic-Water Shutoff Map

A usable valve map tells the next technician what a valve actually serves. Build it before a leak, without experimenting on occupied-building systems.

Mop Sink Hose Left in a Bucket: Prevent a Cross-Connection

A hose submerged in dirty water can create a path for contamination if supply conditions change. Keep cleaning equipment separate from drinking-water plumbing.

Several Restroom Drains Backing Up: Stop Adding Water

When a toilet, sink and floor drain back up together, treat the problem as a shared drainage issue. Repeated flushing can turn a blockage into a contaminated-water incident.

How to Change a Bottleless Water Dispenser Filter

Identify the exact filter, isolate and relieve water pressure, photograph the flow direction before disconnecting, install the approved cartridge the same way, restore water slowly and flush per the manufacturer.

Water Dispenser Leaking: Safe First Response for Maintenance

Protect the area, stop use, close the dispenser's known water-supply shutoff if it can be identified and operated safely, and disconnect power only when the plug and surrounding area are dry and safely accessible. Then dry the area and observe where fresh water first appears.