Why is my sprinkler system leaking when no zones are running?
Short answer: A leak on the pressurized irrigation mainline can continue losing water regardless of whether a sprinkler zone is operating. If water is moving with every zone off, the leak is before the zone valves, not in a zone.
A leak on the pressurized irrigation mainline can continue losing water regardless of whether a sprinkler zone is operating. The mainline runs from the water supply to the zone valves and stays under pressure all the time, so a crack or a loose fitting there leaks around the clock — not just during a watering cycle.
In Humble the first test is the water meter: with every tap off and the controller off, watch the meter’s low-flow indicator. If it is moving, close the irrigation isolation valve. If the meter stops, the leak is on the irrigation side — the mainline or a valve that is passing water.
A mainline leak is the one to find fast, because it never stops on its own. It can run for weeks unnoticed, soften the soil along its path, and show up as a soggy strip, a sinkhole, or a water bill that climbs with no change in watering.
What we check in Humble
This is a common call in Humble, and it is the kind of problem we test in the yard instead of guessing at from the driveway. We run the system, watch how the water is actually moving, and check the parts that cause this — before anything gets replaced. That is the same approach in the full Sprinkler Repair service page.
Related reading: Sprinkler Repair in Humble · All questions · Contact us
Frequently asked questions
How do I tell a mainline leak from a lateral leak?
A mainline leak loses water with every zone off. A lateral leak only shows while its zone is running. The meter test with the irrigation shutoff closed sorts the two in a few minutes.
Do I need a professional to look at it?
If the problem keeps coming back, or you cannot see where the water is going, have the system tested before replacing parts. Testing finds the cause instead of guessing at it. Call or text (281) 504-9998 and we will run the system and tell you what we find.
Do you serve Humble?
Yes. Orion’s Rain serves Humble and the Lake Houston area — Kingwood, Atascocita, Porter, Humble, New Caney, Summerwood, Fall Creek, Huffman, and Eagle Springs. Call or text (281) 504-9998, 24 hours a day.
Related questions
- Why does an irrigation mainline stay under pressure?
- Can my water meter help identify an irrigation leak?
- Why does a broken lateral line leak only when that zone runs?
Get it looked at
If this sounds like your yard in Humble, call or text Orion’s Rain at (281) 504-9998 — 24 hours a day. We will test the system and tell you what is actually wrong, and what it will take to fix it the right way.
Sources: Leak Detection Bargersville, How to Find a Leak in Your Sprinkler System; EngineerFix, How to Find a Leak in Your Irrigation System.
Orion’s Rain Smartscapes and Exteriors — (281) 504-9998 — LI0029444