Water reaches your house through a service line that runs underground from the meter, usually near the street, to the main shutoff at the house. In many older Fullerton homes that line is as old as the house. It can leak just like the lines under the slab, and the symptoms on the bill look the same.
The difference matters because the fix is different: a service line repair means digging in the yard or using a trenchless method outside, while a slab leak is inside the foundation.
The shutoff test
- Confirm a leak.With all fixtures, appliances and irrigation off, check that the meter's leak indicator is moving.
- Close the house shutoff.Close the main shutoff valve where the line enters the house.
- Watch the meter.If the indicator stops, the leak is inside the house, which includes under the slab. If it keeps moving, the leak is between the meter and the house shutoff.
- Check irrigation branches.If irrigation tees off before the house shutoff, close the irrigation valve too, or note that it could be the source.
Clues that point outside
| Clue | What it suggests |
|---|---|
| A soggy or unusually green strip of lawn between the street and house | Water rising along the service line route |
| Water in the meter box | A leak near the meter or the connection on your side |
| Meter moves with the house shutoff closed | Leak on the service line or an irrigation branch |
| Sinking soil or a damp patch along the walkway | Soil washed out near a leak |
| No warm spot and no damp flooring inside | Consistent with a leak outside the foundation |
Service line leak vs slab leak
Service line (outside)
- Meter moves with the house shutoff closed
- Signs show up in the yard, walkway or meter box
- Repair happens outside the house
- May involve digging or trenchless replacement
Slab leak (inside)
- Meter stops when the house shutoff is closed
- Signs show up as warm floors or damp flooring
- Repair involves the slab, walls or attic
- Spot repair, reroute, lining or repipe
Questions to ask about a service line leak
- Where along the line is the leak, and how was it located?
- Would you repair the section or replace the whole line?
- Can it be done with less digging, and is that suitable here?
- Will you coordinate with the City of Fullerton if the work is near the meter?
- Does the work need a permit?
Common questions
My house shutoff does not close fully. What then?
An old shutoff that will not close is common. The test result will be unreliable; mention it to the plumber, who may recommend replacing the valve.
Can I dig to find the leak myself?
Before digging anywhere, call 811 so underground utilities can be marked. A plumber can usually locate the leak more precisely than digging blind.
Can both lines leak at once?
It is possible, especially in older homes. If the meter slows but does not stop when the house shutoff is closed, mention that to the plumber.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.