How to Stop Noisy Pipes and Water Hammer

Types of noise

• Bang when a valve closes: water hammer.
• Ticking as hot water runs: pipe expansion against framing.
• Rattling: loose pipes or straps.
• Humming or whistling: high pressure or a partly closed valve.

Fixes

1. Secure loose pipes with proper straps and cushioned clamps.
2. Install water hammer arrestors near quick-closing valves such as washing machines and dishwashers.
3. Check pressure. If household pressure is too high, a pressure-reducing valve may be needed.
4. Allow room for expansion where hot pipes rub against wood.
5. Open valves fully that may have been left partly closed.

Old air chambers

Older homes sometimes have air chambers, vertical pipe sections that cushion water. Over time they fill with water and stop working. Draining the system can restore them temporarily.

When to call

Persistent or worsening noises can stress joints. If the piping is old and noisy, repiping may solve several problems at once. Travelling soon? Read preparing plumbing for vacation.

Keeping a noise diary

Note when the sound happens, which tap or appliance was in use and whether it is louder at night. Night-time noise often points to high pressure, since municipal pressure rises when the whole street stops drawing water.

Worth knowing

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