Water use after closing may come from a leak or from equipment that runs outside occupied hours, including irrigation, cooling, cleaning or regeneration. Map the meter’s served area and compare interval readings with actual schedules. Arrange controlled checks of suspect loads. A moving commercial meter does not prove a leak while legitimate automatic demand remains active.
Which loads should be on the overnight list?
Ask the facility team and tenants what can operate after hours:
- Irrigation and landscape controllers.
- Cooling-system makeup or other mechanical loads.
- Cleaning crews, laundry or production shifts.
- Water treatment regeneration or automatic equipment cycles.
- Restrooms used by security, maintenance or another tenant.
- A fixture or valve that fails to shut off.
These are possible loads, not a claim that your building has every one. Record the expected schedule and equipment actually present. An undocumented night shift can explain a pattern that initially looks abnormal.
What data helps separate the possibilities?
Use time-stamped meter information where available. Look for continuous flow, repeated events or a change from the building's own earlier pattern. A pattern narrows the investigation but does not identify one failed component by itself.
If the concern began with a monthly bill, normalize the commercial billing periods first. For a cooling-system load already identified, use the tower makeup and blowdown investigation with the responsible facility specialists.
Commercial submeters can divide tenant, irrigation and process loads. Confirm their served areas and compare identical reading periods. For restroom demand, the fixture baseline helps distinguish scheduled use from running valves.
How should a suspected load be checked?
Inspect accessible equipment and compare readings while authorized staff conduct an agreed operational check. Coordinate with the manufacturer and facility procedures before disabling equipment. Do not shut off an unknown branch or life-safety supply to see whether a number changes.
The planned commercial shutoff guide covers notification and dependent systems. A household-style meter leak test assumes all relevant use can stop; it needs those commercial loads accounted for first.
When should the investigation expand?
If expected demand does not explain the reading, give the plumber the meter map, timestamps, schedules and observations. A commercial leak-detection scope should identify what will be tested and which inaccessible areas remain uncertain. A high bill without a visible leak covers the broader visible checks.
After the cause is addressed, compare equivalent intervals again and record what changed. Keep legitimate scheduled use on the map so the same equipment does not become a suspected leak every month.