Quick Answer:
If pressure fell right after the curb stop was opened or cycled, the most likely causes are trapped air, dislodged debris, or the curb stop not being fully open. Start with simple checks you can do yourself: verify the valve is all the way open, look for leaks, flush debris through a tub spout, and inspect faucet aerators before calling a pro.
Why This Happens
Cycling the curb stop (partially closing and reopening the valve) can dislodge sediment that has built up in the service line or around the meter. That sediment can lodge in fixtures, faucet screens, or pressure devices and reduce flow. Air can also get trapped and make pressure feel weak until it works through the lines.
Other causes that commonly appear after work at the curb are a valve that isn’t fully open or a partially closed pressure-reducing valve. If the meter itself is affected, you may also notice the meter spins when no water is running or unusual readings.
Step-by-Step What to Do
1. Confirm the curb stop is fully open
Locate the curb stop key or valve box and turn the valve slowly until it stops. Do not force it. If you turned it more than a quarter-turn previously, open it fully in small increments and test house pressure.
2. Look for obvious leaks
- Check around the water meter, exposed pipes, and outside spigots for wet spots or drips.
- Listen for running water when all fixtures are off.
3. Flush debris through a tub spout
Open a tub spout or bathtub hot and cold to full for 1–2 minutes to try to clear trapped sediment. Doing this from the tub uses a larger pipe and often clears debris that would otherwise clog a faucet aerator.
4. Inspect aerators and faucet screens
Unscrew the aerator on sinks and check screens for grit or mineral buildup. Rinse or soak the parts in vinegar, brush gently, then reassemble. Clogged aerators are a common cause of low flow after line work.
5. Check indoor shutoffs and the pressure regulator
- Make sure any whole-house shutoff or PRV near the main is fully open.
- If you have a pressure regulator and it was disturbed, it may need minor adjustment or inspection by a pro.
6. Test fixtures one at a time
Turn on different fixtures to see whether the reduction is across the whole house or only certain outlets. If only one fixture is weak after flushing and aerator cleaning, the problem is local to that fixture.
7. If you suspect meter or service-line blockage
Note any odd meter behavior (for example, the meter spinning with no taps open). That detail helps a utility or plumber diagnose a blockage or stuck component.
What Not to Do
- Do not replace fixtures immediately — many low-pressure problems clear after flushing lines or cleaning aerators.
- Do not force a stuck curb stop. Forcing can damage the valve or break the service line.
- Do not dig up the service line or curb stop area without locating utilities and getting permission from your water utility if required.
When to Call a Professional
Call your water utility or a licensed plumber if:
- Pressure does not recover after flushing lines and cleaning aerators.
- You find a leak, or you see the meter behaving oddly, such as a water flow reduced after curb stop scenario that you cannot correct with simple steps.
- There are signs of damage to the curb stop, meter, or buried service line.
Safety Notes
- Turn valves slowly. Rapid movement can break valve stems.
- If you are not comfortable working with the meter or curb stop, stop and call the water utility — meter boxes and curb stops can be the utility’s responsibility in many areas.
- Before digging or doing any excavation, contact local utility locating services to mark buried lines.
Common Homeowner Questions
- Why did pressure drop only after I touched the curb stop?
Tiny debris or air released by the valve can clog downstream screens and regulators; the valve may also not be fully open. - How long should I run fixtures when flushing debris?
Run a large outlet like a tub or outdoor hose at full for 1–3 minutes, then check flow. Repeat if needed. - Can I clean a pressure regulator myself?
Not recommended unless you have experience. Regulators are adjustable and can affect whole-house pressure; call a plumber if you suspect it’s the issue.