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Overnight Meter Test: Is Water Escaping, or Is Your Meter Over-Registering?
2
Water + sewer
7.48
Free
Direct answer: An overnight meter test tells you whether a high bill comes from escaping water or from the meter itself. Read the water meter at closing and again before anyone arrives. If it registered water with nothing scheduled to run, water is escaping, and a steady leak is billed around the clock on water and usually again on sewer. If the meter did not move but the bill is still high, water is not escaping; the extra volume is likely being counted at the meter during demand surges, which is meter over-registration.
How to Run the Test
- Pick a quiet night when nothing is scheduled to use water. If ice machines, a cooling tower or process equipment must run, note it.
- Read the meter at closing. Write down every digit and the time. Check whether it reads in gallons or cubic feet.
- Read it again before anyone arrives, and note the time.
- Enter both readings below. The calculator shows the flow per hour and what it costs if it continues around the clock.
Many meters also have a small low-flow indicator (a triangle or star) that spins whenever water is moving. If it turns while everything is off, water is flowing.
Overnight Meter Test & Leak Cost Calculator
Overnight Meter Test & Leak Cost Calculator
Read your water meter at closing and again before anyone arrives. Enter both readings to see whether water is escaping overnight and what it costs. Your numbers stay in your browser unless you download a report.
This is a planning estimate. The yearly cost assumes the overnight flow continues around the clock, as a leak usually does.
If the Meter Moved: Where Water Usually Escapes
- Running toilets and stuck flush valves
- Cooling tower makeup that will not shut off
- Irrigation valves that will not close
- Water softeners or reverse osmosis systems stuck in a cycle
- Boiler makeup, ice machines, or process equipment left running
- A leak on the service line between the meter and the building
Fix what you find and run the test again. A small steady leak adds up: 48 gallons an hour is about 420,000 gallons a year, billed on water and usually again on sewer.
If the Meter Did Not Move: Check the Meter
A clean overnight test with a high bill points to the meter. During demand surges, when valves open, pumps start or many fixtures run at once, pressure inside the meter drops. Dissolved gas comes out of solution and vapor forms, and the meter, which measures volume, counts that volume as water. It is worst in your busiest hours and months, and it is billed again on sewer. Track your gallons per unit to confirm the pattern, and see Water Meter Over-Registration.
The Flow Conditioning Device (FCD) installs immediately after the meter and creates a small, controlled back-pressure that extends back through it, holding pressure up during surges so far less gas and vapor form and are counted. Pressure loss is under 0.8 psi and nothing downstream changes. It does not fix leaks or reduce the water you use; it corrects what the meter records. Documented installations typically show up to a 30% reduction in water and sewer costs (46% highest documented), starting on the next full billing cycle.