Quick Answer:
If pressure problems began immediately after the city’s work, the likely causes are trapped air, a partially closed curb stop, a disturbed pressure regulator, or a slow leak introduced during the repair. Start by measuring static versus flowing pressure, check valve positions, and look for air or new leaks before assuming it’s only a temporary blip.
Why This Happens
When crews work on the public main, they often shut and reopen valves, flush lines, or isolate sections. That can introduce air pockets, change the position of the curb stop, or shift fittings that affect pressure at your meter. A pressure regulator (PRV) near the property line can be bumped or set incorrectly. Any of these changes can make pressure unstable or cause sudden drops when you open a faucet.
Step-by-Step What to Do
1. Note when the issue started
- Write down the time and which city crews were working if you know. This helps when you contact the water department.
- Check whether every fixture behaves the same (kitchen, shower, outdoor hose) or only some do.
2. Measure static and flowing pressure
- Attach a simple water pressure gauge to an outdoor hose bib or the test port on your meter assembly.
- To get static pressure: make sure no water is running in the house and record the gauge reading.
- To get flowing pressure: open a nearby faucet fully and record the new reading. Note how many psi it drops under flow.
- What to look for: typical static pressure is 40–80 psi. A drop of more than 10–15 psi under flow or wild swings indicates a supply-side issue or a failing regulator.
3. Check valve positions at the meter and curb
- Verify the interior main shutoff and the meter-side shutoff are fully open.
- The curb stop (usually between the meter and the street) can be partially closed after work — if you can access and safely operate it, confirm it’s fully open and snug.
- If the curb stop is hard to reach or you are unsure, call the water department rather than forcing it.
4. Look (and listen) for air and new leaks
- Turn on multiple fixtures briefly — sputtering and intermittent flow often mean air pockets. See the linked note on Air trapped in system after repair for how crews usually bleed the main and what to expect.
- Check around the meter, exposed piping, and inside the house for drips that began after the work. Early leaks may be small but will worsen. See the linked note about Leaks starting days after repair for signs to watch.
5. Inspect the pressure regulator
- If you have a PRV, check for obvious damage or water around it. A bumped regulator can cause either too-high pressure or wild fluctuations.
- If the PRV has an adjustment screw and you are comfortable doing basic work, minor adjustments can be made, but if readings are unclear, get professional help.
6. Document and contact the water department
- Record your static/flowing readings, times, and any audible or visible signs. Provide this information when you call the city — they may re-inspect the connection or curb stop.
- If the utility confirms the public side is fine but instability remains, contact a licensed plumber with your notes.
What Not to Do
- Don’t assume instability will resolve itself.
- Do not attempt to work on the city main, dig into the street, or force curb stops that you cannot access safely.
- Don’t ignore new small leaks — they can become larger quickly and can cause water damage.
- Don’t over-tighten fittings or make large PRV adjustments without proper testing; that can make the problem worse.
When to Call a Professional
- Call the water department immediately if the meter or public-side curb stop is leaking or if crews left hardware exposed.
- Call a licensed plumber if you see:
- a drop of more than 10–15 psi under flow with normal static pressure,
- repeated large pressure spikes or hammer,
- visible leaks near the meter or inside the house that you cannot safely isolate.
- If the PRV appears damaged or you need the regulator replaced, hire a plumber to test and install a replacement.
Safety Notes
- Do not attempt to work on the public main or dig near the curb; contact the utility for any work on the street side.
- Shutting off the house valve is usually safe, but make sure you know how to re-open it and that you won’t freeze or damage appliances. If in doubt, wait for a pro.
- Beware of electrical equipment near wet areas when checking for leaks. Shut electricity off to affected areas if water is present near outlets.
Common Homeowner Questions
- Who pays if the city broke something? The utility is typically responsible for the public main and curb stop; document the issue and file a claim with them.
- Can trapped air hurt appliances? Short-term air usually causes sputtering and noise; prolonged erratic pressure can stress appliances — have a plumber check persistent issues.
- How long should I wait for the city to fix it? Response times vary; report the problem immediately and follow up with your pressure readings and notes to encourage a timely inspection.