Quick Answer:
If an outdoor spigot began leaking while you or a technician were testing indoor fixtures, first confirm which indoor area was worked on, then operate the house isolation valves while watching the spigot. The leak is often from a partially open isolation valve, a disturbed compression nut on the spigot supply, or a loosened fitting along the supply run. Trace the supply, visually inspect fittings, and pressure-test the repaired section. If the leak links to work recently done, contact the installer for a follow-up inspection.
Why This Happens
Indoor testing changes flow and pressure in the same branch that feeds an exterior spigot. Common causes after service include:
- A shutoff or isolation valve left partially open — this can raise flow through the spigot line or allow pressure pulses that reveal a weak fitting.
- A compression nut or threaded fitting that was bumped during work and is now leaking when the system is pressurized.
- A weakened joint that tolerated low idle pressure but fails under test pressure.
Similar timing and pressure patterns are seen in situations like Spigot leaks after city outage, and the same inspection steps apply when leaks change with system pressure.
Step-by-Step What to Do
1. Confirm which area was worked on
Ask or verify which fixture(s), valves or lines the technician accessed. Knowing the exact room and the shutoffs used narrows which supply branch to inspect.
2. Watch the spigot while operating isolation valves
Run this quick test:
- Locate the house isolation valves (individual fixture shutoffs, line shutoffs, and the main shutoff).
- Have someone slowly open and close the valve that isolates the repaired area while you watch the outdoor spigot for changes in flow or leaking at the spigot connection.
If the leak changes when that valve moves, a partially-open valve or a disturbed nut in that branch is likely the cause.
3. Trace and visually inspect the supply runs
Follow the piping from the repaired area to the spigot point of connection. Look for:
- Loose compression nuts, visible drips or wet spots along joints.
- Fresh tool marks, fingerprints, or disturbed insulation that indicate a recent touchpoint.
- Soft or cracked pipe where a wrench may have slipped.
4. Pressure-test the repaired sections
If you can isolate the branch, pressurize it and watch for leaks:
- Close the appropriate shutoffs so only the repaired section is isolated, then slowly open supply to pressurize that section.
- Watch fittings and the spigot. If the leak appears or worsens under higher pressure, it points to a disturbed joint.
- Be cautious—if you’re unsure how to isolate or pressurize a branch, stop and call the installer or a licensed plumber.
If the evidence shows the leak is tied to the recent service, contact the installer for a follow-up and repair under their workmanship terms.
What Not to Do
- Avoid cutting into exterior lines yourself without the right tools and experience. That can make the problem worse and create an emergency.
- Don’t hide the problem with temporary clamps or tape as a long-term fix; temporary measures can fail and cause water damage.
- Call a professional when the leak began right after service or when you cannot identify the loosened or disturbed joint.
When to Call a Professional
Contact a licensed plumber or the original installer if any of these apply:
- The leak started immediately after their work — ask them to return and inspect.
- You cannot locate the origin of the leak or it runs inside walls or under slabs.
- The leak increases when pressure rises, or you see steady flow that you cannot stop with isolation valves.
- There is visible water damage, soft flooring, or risk of freezing in cold weather.
For pressure-related problems, consider reading about Leak worsens when water pressure high as part of your symptom checklist before the pro arrives.
Safety Notes
- Turn off the main water supply before cutting or disassembling pipes. Know how to shut the water back on safely.
- Beware of electrical hazards near wet areas. If water has reached outlets or appliances, shut off power at the breaker and call an electrician if needed.
- Use eye protection and gloves when inspecting or working on fittings. Avoid makeshift tools or force that can damage fittings.
- If you are unsure about isolating or pressure-testing plumbing, stop and call a professional — it’s safer and often faster.
Common Homeowner Questions
- Could a technician leave a valve partially open?
Yes. It’s a common cause; observing the spigot while operating isolation valves will show this quickly. - Can I tighten a compression nut myself?
Tightening can help if the nut is loose, but overtightening can damage fittings—only do this if you’re confident and the system is depressurized. - Will turning off the main stop the leak?
Turning off the main stops the flow but won’t fix the damaged joint; it prevents further water damage until repairs are made.
More in this topic
For more related fixes and similar symptoms, see Outdoor Spigot Leaks Under Load.