Quick Answer:
If water won’t come back on after you closed the main shutoff, don’t force the valve. Start by opening a downstream faucet slightly to relieve pressure, relieve any vacuum in the system, then try to re-cycle the valve slowly. If those steps don’t restore flow or the valve leaks, call a plumber or the water utility.
Why This Happens
Several common problems stop a main shutoff from reopening: corrosion or mineral buildup on the valve seat, debris trapped in the line, a valve stem that’s seized from age, or water inside the valve that has frozen. In very cold weather the valve or nearby pipe can ice up (Main shutoff frozen in winter), and in other cases the handle may get stuck partway so flow only returns weakly or not at all (Main shutoff valve stuck halfway).
Step-by-Step What to Do
Step 1 — Stay calm and prepare
Shut off any appliances that use water (water heater, washing machine) if possible and open a nearby basin to check flow when you attempt to reopen the main. Keep towels and a bucket handy in case a slow leak starts.
Step 2 — Crack a downstream faucet
Open a faucet that is downstream of the main shutoff (a sink or hose bib inside the house). Opening it slightly will let trapped pressure escape and shows whether any flow returns when you work the main valve. Leave this faucet open while you test the main.
Step 3 — Relieve vacuum in the line
Before you try to operate the main, open a second faucet or the highest indoor faucet briefly to allow air into the system. This helps relieve any vacuum so water can resume flowing once the valve moves. Keeping at least one faucet open also makes it easier to see small flow and reduces the chance of water hammer.
Step 4 — Re-cycle the valve slowly
Attempt to reopen the valve slowly: turn it partway open, wait a few seconds, then continue to fully open. If it’s a gate or ball valve, use steady, moderate force rather than jerking. Work the valve a few times (close slightly, then reopen) to free debris. Rushing or forcing it can strip the stem.
Step 5 — Look for obvious signs and leaks
- Listen for water flow at the open faucet you left running.
- Check around the shutoff for leaks or wet ground outside where the curb stop or meter is located.
- If nothing moves and you suspect ice, warm the area gently (see safety notes) and don’t apply open flame.
Step 6 — If it still won’t reopen
If you can’t get any flow, the valve may be seized or inside components damaged. At this point stop trying to force it and contact the water utility if the curb stop is outside, or a licensed plumber if it’s inside. Continuing to force a stuck stem risks breaking the valve or causing a leak.
What Not to Do
- Do not hammer stem trying to open. Striking the valve can break internal parts or the stem and create a sudden major leak.
- Do not use an open flame or torch to thaw pipes or a frozen valve.
- Do not overtighten with excessive wrench force; that can snap the valve or shear the stem.
When to Call a Professional
Call a plumber or your water utility if:
- The valve won’t move after the steps above.
- Turning the valve causes a leak or you hear running water inside walls or under the slab.
- You suspect frozen pipes that you cannot safely thaw, or the valve is damaged or sheared.
Safety Notes
- Turn off electricity to any area with standing water to avoid shock risk.
- Wear gloves and eye protection when working around valves and meters.
- Never use an open flame to thaw frozen pipes or valves. Use warm air from a hair dryer, heat tape, or call a professional.
- If you smell gas or see major flooding, evacuate and call emergency services immediately.
Common Homeowner Questions
- Q: How long should I try to free a stuck valve?
A: A few careful attempts are fine, but stop if there’s no movement or if the valve feels brittle; call a pro. - Q: Can I replace the main shutoff myself?
A: Replacing a main shutoff often requires shutting off the curb stop and plumbing permits; it’s best handled by a licensed plumber. - Q: Will turning the water back on quickly cause damage?
A: Slowly reintroducing flow reduces pressure surges; opening valves too fast can cause water hammer and stress fittings.