Tapping Noise in Sprinkler Lines: Water Meter or Water Hammer?

Diagnosing That Annoying "Tapping" Sound

A constant tapping noise when sprinklers run usually comes from one of three sources:

1. Water Meter (Most Common)

Modern positive-displacement meters (nutating disc, piston) make a rhythmic tick-tick-tick as water passes. Utilities often say "that's normal."

Fix: Partially close the irrigation supply valve (at backflow preventer) to reduce flow velocity 10–20%. Often eliminates the noise without hurting coverage.

2. Water Hammer (Single Bang)

If it's a loud BANG at valve closure, that's water hammer. Fix with flow control adjustment or pressure-reducing valve.

3. Loose Pipe in Wall/Ceiling

Pipe straps missing or loose. Tap along the run to locate, then secure with insulated clamps.

Test to Confirm Meter Noise

1. Run a single zone. 2. Listen at the water meter. 3. If tapping matches meter, throttling the supply valve usually quiets it.

No need to replace the meter—utility owns it. Flow restriction is the practical DIY fix.