The meter test is the single most useful thing a homeowner can do before calling about a suspected slab leak. This worksheet turns it into three short rounds with a place to write each reading, so nothing depends on memory.

You need a pen, your phone camera, a flat screwdriver or meter key for the lid and about thirty minutes with nobody using water.

Before you start: turn these off

  • All faucets, showers and tubs.
  • Dishwasher, washing machine and any running cycle.
  • Ice maker and refrigerator water dispenser (pause if possible).
  • Water softener regeneration (bypass if possible).
  • Every irrigation timer and the drip system.
  • Check that no toilet is refilling; listen at each one.

Round 1: everything off

Write the full meter reading, not just the leak indicator.
LineTimeMeter readingLeak indicator moving? (yes/no)
Start____________________
After 15 minutes____________________
After 30 minutes____________________
Change in reading____________

Round 2: house shutoff closed

Only needed if round 1 showed movement. The house shutoff is where the line enters the home.
LineTimeMeter readingIndicator moving?
House shutoff closed____________________
After 10 minutes____________________
Did the shutoff close fully? (yes/no/unsure)____

Round 3: water heater cold inlet closed

Reopen the house shutoff first. Close only the cold water valve feeding the heater; leave gas controls alone.
LineTimeMeter readingIndicator moving?
Heater cold inlet closed____________________
After 10 minutes____________________
Heater cold inlet reopened at____

Reading your worksheet

  • IfRound 1: no movement and no reading changeThenNo continuous leak right now. Repeat on another day and check toilets and irrigation schedules.
  • IfRound 1 moves, round 2 stopsThenThe leak is inside the house. Do round 3 to find the side.
  • IfRound 2 keeps movingThenThe leak is likely between the meter and the house, or on an irrigation branch.
  • IfRound 3 stopsThenLikely a hot-side leak. Keep the heater inlet closed except when you need hot water.
  • IfRound 3 keeps movingThenLook at the cold side: re-check toilets, then consider cold-line slab leak location.

Common questions

Do I need all three rounds?

Only if round 1 shows a leak. Rounds 2 and 3 narrow down where it is.

Should I photograph the meter too?

Yes. A photo of each reading with the time is the best backup for the worksheet.

What if my house shutoff is stuck?

Do not force it. Write "stuck" on the sheet and mention it to the plumber; old shutoff valves are commonly replaced.

General information for Fullerton, not a quote or professional advice. In an emergency, call 911.