Repair Library

88 guides

No Cooling: Full Troubleshooting Guide

Confirm the call for cooling at the thermostat, confirm the unit has power and is not locked out on a safety, then check the two things that cause most no-cooling calls: a loaded filter and a plugged condensate drain with a tripped float switch. Anything involving refrigerant, energized troubleshooting, or gas requires a licensed technician.

Leaks & Building

Water Leak: Find the Source and Control the Damage

Stop the water if there is an accessible isolation valve, keep people and electricity away from it, then trace the path from the lowest wet point up to the highest. Condensate, roof, supply piping, and drain leaks all look the same on a ceiling tile.

Plumbing

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.

Plumbing

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.

Doors & Hardware

Door Problem: Latching, Closing, and Hardware

Watch the door through a full swing before touching a tool. Most problems are a loose hinge screw, a misaligned strike, or a closer that needs a sweep and latch adjustment. Fire-rated and egress hardware must keep working as listed: no wedges, no disabled closers, no field modifications.

Electrical & Lighting

Electrical Problem: Conservative Field Checks

Confirm the scope of what is dead, test the GFCI and breaker once, and unplug suspect loads. If a breaker trips again, if you smell burning, or if any panel or device needs to be opened, stop and call a licensed electrician. Do not take live readings unless that is your qualified, authorized work.

Electrical & Lighting

Lighting Problem: Flicker, Outage, and Controls

Count the fixtures. One fixture out is usually a lamp, driver, or ballast. A whole row or zone out is a circuit or control problem. Flicker after an LED retrofit usually means a driver or dimmer compatibility issue. Fixture wiring and ballast replacement is qualified work in most sites.

HVAC

HVAC Problem: General Triage for Any Complaint

Sort the complaint into temperature, airflow, humidity, water, or noise. Each has a short list of routine checks facility staff can do: schedules and setpoints, filters, dampers and returns, condensate, and outdoor-unit clearance. Refrigerant, gas, combustion, and energized electrical work is licensed-technician work.

Doors & HardwarePro

Automatic Door Won’t Open: Safe Facility Checks

An automatic pedestrian door that will not open can be in the wrong mode, lose power, have a blocked sensor, remain mechanically locked, or have an operator fault. Keep routine checks external.

Leaks & BuildingPro

Basement or Lower-Level Water After Heavy Rain: First Checks

Lower-level water after storms often comes from exterior drainage, foundation joints, floor drains, sump failure, window wells, or sewer backup. First separate clean rainwater from sewage and electrical hazards.

Electrical & LightingPro

Breaker Keeps Tripping? What Facility Maintenance Can Check Safely

A breaker that repeatedly trips is signaling a real problem such as overload, short circuit, ground fault, or failing equipment. Identify what lost power, remove obvious loads, and do not keep resetting a breaker that trips again.

Leaks & BuildingPro

Ceiling Leak After Rain? How to Trace Where the Water Is Coming From

A wet ceiling tile often is not directly below the exterior leak. Rainwater can travel along roof decking, framing, conduit, piping, insulation, or wall cavities, so document the wettest point and trace the path upward and outward.

Doors & HardwarePro

Commercial Door Won’t Latch: A Simple Alignment Checklist

A commercial door that closes but will not latch is often sagging slightly, rubbing, hitting a misaligned strike, or moving too slowly through the final inch. Use wear marks and door gaps to identify what shifted before filing or moving hardware.

PlumbingPro

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.

PlumbingPro

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.

Preventive MaintenancePro

Commercial HVAC Filter Change Schedule: Stop Guessing and Use Condition

There is no universal 'change every 90 days' rule for commercial HVAC filters. Occupancy, construction dust, filter efficiency, outdoor-air load, runtime, and system design all matter. Build your interval from inspection history and pressure-drop data where available.

PlumbingPro

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.

PlumbingPro

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.

Plumbing

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.

PlumbingPro

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.

HVACPro

Condensate Pump Not Working: Safe Checks Before Replacement

A condensate pump that stops moving water can shut down cooling or overflow. Check safe external power, the reservoir, float movement, and discharge tubing before replacing the pump.

Leaks & BuildingPro

Cracked Exterior Sealant: When to Recaulk and When Not To

Failed exterior sealant can admit water and air, but smearing new caulk over old material rarely lasts. Proper repair means removing failed sealant, preparing the joint, and preserving designed drainage paths.

Preventive MaintenancePro

The 10-Minute Building Walk That Prevents Expensive Problems

A consistent daily walk catches leaks, odors, hot/cold complaints, restroom issues, door problems, abnormal equipment sounds, and safety hazards while they are still small. The value comes from walking the same route and comparing today's building to yesterday's.

Electrical & LightingPro

Dead Electrical Receptacle: Safe First Checks for Facility Maintenance

A dead receptacle may be switched, protected by an upstream GFCI, on a tripped breaker, intentionally de-energized, or part of a wiring fault. Maintenance can check obvious upstream protection and compare nearby outlets without removing energized covers.

Preventive MaintenancePro

What to Document Before Calling HVAC, Plumbing, or Electrical Service

A good service call starts with evidence: exact location, symptom, equipment identity, controller readings, error codes, timing, affected areas, and what changed recently. Five minutes of documentation can prevent repeat trips and reduce diagnostic time.

Doors & HardwarePro

Commercial Door Closer Arm Is Loose: How to Inspect and Tighten It

A loose closer arm can make a door slam, stop short, bind, or lose control. Secure the arm, shoe, spindle connection, and closer body before touching hydraulic adjustments.

Doors & Hardware

Commercial Door Closer Slamming? How to Adjust Sweep & Latch Speed

Most hydraulic commercial door closers have separate sweep and latch-speed adjustments. Make very small valve changes, test the full closing cycle after each change, and stop if the closer is leaking oil or the adjustment valve is near its limit.

Doors & HardwarePro

Commercial Door Closer Won’t Close the Door: What to Check

A commercial door that stops before latching may have the closer adjusted too slowly, weak spring power, binding hinges, weatherstripping resistance, frame misalignment, or building pressure. Check mechanical drag before turning closer valves.

Doors & HardwarePro

Commercial Door Hinge Screws Keep Loosening: Find the Real Cause

Hinge screws that repeatedly loosen may indicate stripped holes, hinge wear, wrong fasteners, door sag, vibration, or a damaged frame reinforcement. Re-tightening every week is not a repair.

Doors & HardwarePro

Commercial Door Hinge Squeaking: Clean, Lubricate, or Replace?

A squeaky hinge may only need cleaning and the correct lubricant, but recurring squeaks can indicate dry bearings, wear, misalignment, or excessive door load.

Doors & HardwarePro

Commercial Door Key Hard to Turn: Lock, Latch, or Alignment?

A key that is hard to turn may be a cylinder problem, but often the latch or deadbolt is loaded against the strike because the door is sagging or being pushed by seals or pressure.

Doors & HardwarePro

Commercial Door Rubbing the Frame: How to Find the Cause

A rubbing door usually means hinges loosened, the door sagged, the frame shifted, weatherstripping swelled, or floor clearance changed. Use rub marks and reveal gaps before adjusting hardware.

Doors & HardwarePro

Commercial Door Sweep Dragging: How to Adjust or Replace It

A sweep that drags too hard can stop a closer from latching and make the door difficult to use. Adjust height or replace the sweep instead of increasing closer force.

HVACPro

RTU Economizer Damper Stuck Open: Signs and Safe Checks

An economizer stuck open can make a building humid, hot, cold, or pressurized. Maintenance can compare commanded versus visible damper position and check for obvious mechanical obstruction.

Electrical & LightingPro

Emergency Light Battery Won’t Hold a Charge? What to Check

If an emergency light fails its required test duration, first verify that normal power and charging are present. An aged battery is common, but charger faults, lamp problems, or loss of normal-power sensing can produce similar symptoms.

HVACPro

HVAC Evaporator Coil Frozen: What to Do Before It Becomes a Bigger Problem

Ice on an evaporator coil is a symptom. Low airflow, dirty filters, fan problems, blocked coils, controls, or refrigerant conditions can all contribute. Stop cooling and let the coil thaw naturally.

Electrical & LightingPro

Exit Sign Not Lit: Facility Troubleshooting Checklist

An unlit exit sign may have lost normal power, failed LEDs, a bad battery or charger, or internal electronics trouble. Document and correct it promptly because it is part of the egress system.

Leaks & BuildingPro

Water Coming Under an Exterior Door: How to Find the Entry Path

Water at an exterior door can come through the threshold, failed sealant, door sweep, jambs, masonry joints, or exterior drainage that sends water toward the opening. Start outside and follow the path instead of immediately replacing weatherstripping.

Doors & HardwarePro

Fire Door Hold-Open Magnet Won’t Release: What Maintenance Should Check

A magnetic fire-door holder that will not release on alarm is a life-safety defect. Maintenance can check mechanical binding and observe release during an approved test, but should not alter fire-alarm wiring.

PlumbingPro

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.

Electrical & LightingPro

Fluorescent Light Humming or Buzzing: What It Usually Means

A buzzing fluorescent fixture can indicate an aging ballast, failing lamp, loose component, or magnetic ballast vibration. Heat, odor, flicker, or discoloration make the issue more urgent.

PlumbingPro

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.

PlumbingPro

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.

Electrical & Lighting

GFCI Won’t Reset? Safe Checks Before Replacing the Receptacle

A GFCI that will not reset is not automatically bad. Unplug connected equipment, check for moisture, verify upstream protection, and try one firm reset. If it trips again or shows heat, odor, or damage, take it out of service and escalate.

Leaks & BuildingPro

Commercial Gutter Overflowing: Find the Blockage or Capacity Problem

Overflowing gutters usually come from debris, blocked downspouts, poor slope, undersized drainage, or roof water overshooting the gutter. Watch where the water actually goes.

HVAC

HVAC Condensate Drain Clogged? How to Clear a Routine Blockage

A clogged condensate drain can stop cooling, trip a float switch, overflow a pan, or stain a ceiling. If the drain and cleanout are safely accessible, remove buildup and verify that water flows freely before putting the unit back in service.

HVACPro

HVAC Float Switch Tripped: What It Means and How to Reset It Safely

A tripped condensate float switch is a warning, not the root cause. The right fix is to correct the drainage problem, remove standing water, confirm the line drains, and allow the safety to reset naturally rather than bypassing it.

HVACPro

HVAC Short Cycling: What Maintenance Can Document Before Service

Short cycling means equipment starts and stops more frequently than expected. Time the cycles and record thermostat demand, airflow, faults, and weather rather than repeatedly resetting the unit.

Plumbing

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.

Electrical & LightingPro

Commercial LED Light Flickering: What to Check Before Calling an Electrician

Commercial LED flicker can come from a failing driver, loose lamp, incompatible dimming/control, unstable power, a failing retrofit tube, or occupancy controls. The most useful first step is defining whether the issue follows one lamp, one fixture, one control zone, or a whole circuit.

Electrical & LightingPro

LED Tube Still Doesn’t Work After Replacement: What to Check

When a replacement LED tube stays dark, the issue may be wrong lamp type, incompatible ballast, ballast-bypass wiring, failed sockets, or no fixture power. Identify the retrofit method before swapping more lamps.

Electrical & LightingPro

Commercial Light Switch Not Working: Safe First Checks

A wall switch that appears dead may actually be part of an occupancy-control system, lighting contactor, BAS schedule, dimming system, or tripped circuit. Map what is affected before touching wiring.

Doors & HardwarePro

Loose Commercial Door Lever Handle: How to Tighten It Correctly

A loose commercial lever is often caused by a loose set screw, rose/trim fasteners, through-bolts, or wear inside the lockset. Tighten the correct fastener and verify the latch works smoothly rather than simply cranking on the visible handle.

Preventive MaintenancePro

Mechanical Room Monthly Inspection Checklist

A monthly mechanical-room walk catches water leaks, abnormal sounds, blocked access, dirty filters, pump issues, chemical storage problems, and changing gauge readings before they become shutdowns.

HVACPro

Mini-Split Leaking Water Indoors? Drain, Pan & Coil Checks

Water from a wall-mounted mini-split usually points to a condensate problem: a clogged drain, dirty pan, poor hose slope, disconnected line, frozen coil, or failed condensate pump. Start with the drain path and visible water source.

Preventive MaintenancePro

Monthly Commercial Restroom Inspection Checklist

Restrooms generate a constant stream of small maintenance problems. A monthly inspection of flushometers, faucets, drains, partitions, accessories, caulk, exhaust, lighting, and hidden leaks catches water waste and user complaints before they become emergencies.

Preventive MaintenancePro

Monthly Commercial Roof Walk Checklist

A roof walk is about finding changes: blocked drains, loose debris, membrane damage, open flashings, standing water, and equipment-service damage. Use the same route and photos each time.

Preventive MaintenancePro

Commercial Water Heater Monthly Inspection Checklist

A monthly water-heater inspection should focus on leaks, temperatures, relief-valve discharge evidence, recirculation condition, unusual sounds, and housekeeping without casually operating safety devices.

Electrical & LightingPro

Occupancy Sensor Light Won’t Turn Off: Easy Checks Before Replacement

Lights that stay on with an occupancy sensor are often caused by a long time delay, sensitivity settings, air movement, moving objects, line-of-sight traffic, or an override mode. Start with settings and the room before replacing the sensor.

Electrical & LightingPro

Occupancy Sensor Lights Turn Off Too Soon: Fix the Annoying Problem

Lights that shut off while a room is occupied usually have too-short delay, poor sensor placement, low sensitivity, blocked line of sight, or a technology mismatch.

Electrical & LightingPro

Outdoor Light Won’t Turn On at Night: Photocell and Timer Checks

Exterior lighting that stays off at night may be controlled by a photocell, astronomical timer, BAS schedule, contactor, breaker, or fixture driver. Identify the control method first.

Doors & HardwarePro

Panic Bar Sticking: Routine Checks Before You Replace Hardware

A panic bar that sticks or does not fully retract can be caused by door sag, dirty latch areas, loose trim, misaligned strikes, or worn hardware. Because panic hardware is life-safety equipment, routine checks should stay conservative and the door must always release freely from the egress side.

Leaks & BuildingPro

Cold Pipe Sweating: Condensation or a Plumbing Leak?

Water on a cold pipe is often condensation, especially on chilled-water and cold-water lines in humid spaces. Dry the pipe and watch where moisture reforms before calling it a leak.

Electrical & LightingPro

Power Strip or Surge Protector Keeps Tripping: Facility Troubleshooting

A power strip that repeatedly trips is often overloaded, damaged, or being used for high-wattage equipment such as heaters, microwaves, refrigerators, or coffee makers.

Preventive MaintenancePro

Pre-Summer Commercial HVAC Checklist for Facility Teams

The best time to discover clogged condensate drains, dirty filters, failed fans, and dead thermostats is before the first hot week. Focus on airflow, drainage, controls, and obvious operation.

Preventive MaintenancePro

Pre-Winter Building Maintenance Checklist

Winter preparation should focus on freeze exposure, heating operation, exterior doors, roof drainage, and spaces where cold air can reach piping. Do it before the first hard freeze.

Preventive MaintenancePro

How to Build a Preventive Maintenance Calendar That Actually Gets Done

A usable PM calendar is simple, equipment-specific, assigned to a person, and tied to recurring work orders. Start with critical assets and common failure points instead of trying to document every component in the building on day one.

Preventive MaintenancePro

Quarterly Commercial Door Inspection Checklist

Doors fail gradually through loose hinges, leaking closers, latch misalignment, damaged panic hardware, and worn seals. A short quarterly inspection catches these before they become security or life-safety problems.

Leaks & BuildingPro

Commercial Roof Drain Clogged? Safe Inspection and First Response

A clogged roof drain can create dangerous ponding quickly. From a safe, approved roof-access position, remove loose surface debris and clear the drain strainer without entering deep standing water or probing into the drain line.

Leaks & BuildingPro

Commercial Roof Leak: First Response Checklist for Maintenance Staff

The first job during a roof leak is not permanent repair—it is protecting people and property, controlling interior water, documenting the leak, and giving the roofer enough information to find the source. Safe documentation during the event often saves hours later.

HVACPro

One Room Is Too Humid: Commercial HVAC Troubleshooting

High humidity in one room can come from excess outdoor air, low cooling runtime, exhaust imbalance, moisture sources, sensor error, or airflow problems. Measure temperature and relative humidity before changing setpoints.

HVAC

RTU Fan Runs but No Cold Air: What Maintenance Should Check

If the rooftop fan runs but supply air is not cooling, the airflow circuit is alive but the cooling stage may be locked out, not commanded, or unable to operate. Gather evidence before calling service.

HVACPro

Rooftop Unit Not Cooling? Safe Checks Before Calling HVAC Service

When an RTU is not cooling, confirm that the building is actually calling for cooling before assuming a refrigeration failure. Check schedules, thermostat demand, filters, airflow, obvious alarms, and condensate safeties, then document what the unit is doing.

PlumbingPro

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.

PlumbingPro

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.

Leaks & BuildingPro

Supply Diffuser Sweating: Why It Happens and What Maintenance Can Check

A sweating supply diffuser usually means the diffuser or nearby duct surface is below the room's dew point. High indoor humidity, missing duct insulation, air leakage around the boot, low supply temperature, or poor airflow can all contribute.

HVACPro

Commercial Thermostat Screen Is Blank: What to Check First

A blank thermostat can mean dead batteries, lost 24-volt control power, a tripped condensate float switch, equipment power loss, or a loose thermostat face.

HVACPro

Thermostat Temperature Reading Is Wrong: How to Check It

A thermostat that reads several degrees off may be influenced by sunlight, wall temperature, drafts, local heat sources, remote-sensor configuration, or calibration. Verify with a good thermometer first.

HVACPro

Thermostat Says Cooling but Nothing Happens? Commercial HVAC Checks

If the thermostat shows a cooling call but the equipment does nothing, separate the problem into controls, airflow, and equipment response. Verify the schedule and setpoint first, then look for obvious safeties, alarms, airflow restrictions, or a unit that is not responding.

PlumbingPro

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.

PlumbingPro

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.

HVACPro

VRF One Zone Not Cooling: How to Narrow Down the Problem

When one VRF indoor unit is warm but the rest of the system is cooling, the failure pattern is the biggest clue. Start with local controls, mode conflicts, airflow, sensors, branch components, and fault codes before assuming a system-wide refrigerant problem.

Leaks & BuildingPro

Water Stain on a Wall but No Rain: What to Check

A wall stain without rain can come from plumbing, condensate, chilled pipes, restroom fixtures, irrigation, stored roof water, or cleaning. Timing and location are your best clues.

HVACPro

Water-Source Heat Pump Not Cooling: Facilities Troubleshooting Checklist

For a water-source heat pump that runs but does not cool, verify thermostat demand, airflow, filter condition, loop-water availability, condensate safeties, and whether neighboring units are affected. Refrigerant and internal electrical diagnosis should be escalated.

Leaks & BuildingPro