Quick Answer:
If you hear banging when no fixtures are running, start by noting when each bang happens and where it seems loudest. Log the time of each noise, listen near the water heater and the main water entry, and check whether the sounds match neighborhood or city pressure activity. If the pattern points to supply-side pressure surges, a plumber can safely test the system and confirm the cause.
Why This Happens
Banging sounds in pipes with no water being used can come from several sources:
- Pressure spikes on the supply side from the water main or nearby work.
- Thermal expansion or cycling of the water heater that shifts pipework.
- Loose straps, hangers, or pipe contact points that amplify small movements.
- Intermittent equipment on the street (pump stations, automatic valves) or neighbors’ irrigation systems creating bursts of pressure.
Sometimes the noise follows municipal activity; for example, you may notice increased noise after nearby valve work or service work. If that fits, pay extra attention to timing and location. Also watch for patterns such as night-only events that look like pressure cycling in the supply system. For more context, consider reading about Noise after curb stop work and Random banging at night.
Step-by-Step What to Do
1. Record exact times and patterns
- Write down the exact time of each bang and how long it lasts.
- Note whether the sound is isolated to certain hours (day, evening, night) or repeats at regular intervals.
2. Check whether neighbors or the city are involved
- Ask nearby neighbors if they hear the same noise and whether their plumbing is affected.
- Contact your water utility or check recent notices (if available) about maintenance or pressure changes in your area. Municipal work and pump cycling can cause short-term surges.
3. Localize the sound at your home
- Go to the basement, utility closet, or where the water heater and main shutoff are located. Listen at the water heater and the main water entry for louder or clearer bangs.
- Try to tell whether the bang is coming from supply-side piping (main entry) or internal appliances.
4. Look for simple, visible causes
- Inspect visible pipes for loose straps or hangers that can be tightened by hand or with simple tools.
- Check that appliances that use water are fully off and that no automatic systems (irrigation, softeners) are cycling.
5. Decide next steps based on what you find
- If the banging lines up with neighbors or municipal activity, document times and tell the plumber — it may be a supply-side pressure issue.
- If the bangs are localized to your water heater or internal plumbing after you’ve ruled out obvious loose pipes, share your observations with a plumber for targeted testing.
What Not to Do
- Don’t start opening walls to track sound. That can damage finishes and create hazards.
- Don’t disable or remove any safety devices (pressure-relief valves, expansion tanks, temperature controls) to try to stop the noise.
- Do not try to adjust or tamper with the pressure regulator or curb stop without professional tools and training. If bangs continue with no fixtures running, have a plumber evaluate pressure control components rather than attempting internal fixes yourself.
When to Call a Professional
- Call a licensed plumber if banging repeats frequently with no water use, if you detect high pressure or hammering that you cannot isolate, or if you notice leaks developing.
- Ask the plumber to test supply pressure, check the pressure-reducing valve or curb stop, and inspect water heater components and pipe supports.
- If the pattern suggests a supply-side surge rather than your internal plumbing, a plumber can safely confirm and coordinate with your water utility if needed.
Safety Notes
- If you shut off the main water, be aware that some appliances (water heaters, boilers) may require special restart procedures. Follow manufacturer guidance or wait for a plumber if unsure.
- Do not bypass or remove safety devices on heaters or pressure systems. Those devices protect against pressure and temperature hazards.
- If you smell gas near a gas-fired water heater or notice corrosion, stop and call a professional. Avoid electrical or open-flame activities around suspected leaks.
Common Homeowner Questions
- Is this an emergency? Not usually immediate, but if banging is loud, persistent, or accompanied by leaks, call a plumber promptly.
- Can I fix water hammer myself? You can tighten loose straps and check appliance cycles, but pressure regulators and curb-side issues need a pro.
- Can city pressure damage my pipes? Yes—sustained high or rapidly changing pressure can stress joints and fittings; have pressure tested if you suspect it.
For more related articles, see the Random Banging With No Water Running hub.