Quick Answer:
You may be hearing pressure surges from the supply side or from equipment in your house (water heater or pressure regulator). Keep a short log of each event and where the sound seems loudest. If the bangs repeat when no taps or appliances are running, have a plumber check the pressure control parts. For more on related noises see Banging with no apparent cause.
Why This Happens
Several simple reasons can make pipes bang in cold months even when no water is being used:
- Municipal or neighborhood supply pressure can fluctuate in winter because of higher demand, hydrant use, or temporary valve changes on the distribution system.
- Your water heater may cycle more in winter, causing thermal expansion and brief pressure changes that travel through the pipes.
- Pressure regulators or an aging expansion tank can fail or lose charge, letting supply-side spikes reach your plumbing.
- Cold weather can change how pipes are supported or how air pockets behave, making noises more noticeable.
If the sound matches times when no fixtures are on, it can point to the supply or to equipment rather than a faucet or valve. For similar situations check Pipes bang when no water is on.
Step-by-Step What to Do
1. Note the time and pattern
- Write the date and exact time of each bang. Note whether it happens at regular intervals or only once in a while.
- Record whether heating systems, well pumps, or other large equipment are running at the same time.
2. Ask neighbors and check local activity
- Check quickly with a neighbor to see if they hear the same noise or if they were using water at the same time.
- Call your municipal water department if you suspect scheduled work or known pressure changes in winter. They can confirm supply-side events.
3. Listen to find the source
- Go to the water heater and the main water entry point and listen during the next event to see if the bang is louder there. This helps localize a surge.
- Try to determine whether the sound comes from inside walls, from a pipe chase, or from the mechanical room.
4. Isolate possible fixtures
- With no major appliances running, shut off individual valves to fixtures briefly to see if the noise continues. This helps rule out a single faulty valve.
- Do not tamper with pressure relief valves, gas controls, or other safety devices—leave those in place.
5. Prepare for a professional check
- Keep your log of times, locations, and any neighbor feedback. If the pattern points to supply-side issues, a plumber can test pressures at the meter and at your regulator safely.
- If banging continues with no fixtures running, arrange a plumber to evaluate pressure control components like the regulator, expansion tank, and arrestors.
What Not to Do
- Don’t start opening walls or disabling safety devices; if bangs continue with no fixtures running, have a plumber evaluate pressure control components.
- Don’t attempt to adjust the gas or electrical controls on water heaters yourself—call a professional if you suspect the heater is involved.
- Avoid long-term ignores: persistent pressure surges can stress fittings and cause leaks over time, so don’t delay getting it checked.
When to Call a Professional
Call a licensed plumber if any of these apply:
- The banging occurs when no water is on and repeats regularly.
- You notice pressure swings at fixtures (sudden high or low flow) or see new leaks.
- Your pressure regulator, expansion tank, or water heater sounds like it’s cycling abnormally.
A plumber can safely measure supply pressure, inspect the pressure regulator and expansion tank, and confirm whether the issue is supply-side or internal to your home.
Safety Notes
- If you find an active leak or a burst pipe, shut off the main water valve and call a plumber immediately.
- Do not disable safety devices such as pressure relief valves or electrical shutoffs on heaters—you could create a dangerous situation.
- When in doubt, stop and call a pro rather than trying risky repairs. A correct diagnosis prevents damage and keeps the system safe.
Common Homeowner Questions
- Why does it only happen in winter? Colder weather changes demand and equipment cycling; supply pressure and thermal behavior in pipes can be different in winter.
- Could freezing cause this? Freezing itself usually causes blockages or bursting; the banging is more often from pressure swings, not ice movement.
- Is this an emergency? Not usually, but persistent bangs with no water use deserve a plumber’s evaluation to avoid long-term damage.
For more related articles, see the Random Banging With No Water Running hub.