Thermal ticking after dishwasher cycle

Plumbing pipes making ticking or clicking noises

Quick Answer:

If you hear a ticking noise after a dishwasher finishes a hot cycle, it’s most often thermal contraction as hot water cools in the supply or drain pipes and pipe clips shift slightly. That ticking can travel through cabinets and finished walls and sound louder than it actually is. If the noise spreads through finished walls or ceilings, have a plumber check the pipe routing and verify safe support points so you don’t damage finishes or wiring when trying to stop the noise yourself.

Why This Happens

Pipes expand when hot water runs and then contract as they cool. The contraction can pull a pipe against a clip, bracket or framing and produce a sharp tick each time it slips, or a series of softer ticks while it settles. Materials behave differently: copper, PEX and plastic drains all move at different rates, and nearby framing or cabinetry can amplify the sound.

Other causes that can sound similar include pressure changes in the supply lines and small impacts from water movement. If the timing follows municipal work or a pressure change in the street, check resources like Ticking after city pressure change. If the sound resembles isolated small impacts, see Clicking that sounds like dripping for a different troubleshooting approach.

Step-by-Step What to Do

1. Reproduce and listen

  • Run hot water at a nearby sink until the dishwasher or the connected pipes are fully warmed, then stop the flow and listen as things cool. This helps confirm the ticks are related to thermal contraction.
  • Note whether the sound fades gradually over a minute or two, or whether it stays sharp and recurring. A gradual fade points to cooling; a steady sharp tick suggests a pipe slipping against a hard clip or a pressure-related event.

2. Isolate the sound location

  • Move around the room and press your ear to cabinet faces to find where the sound is loudest.
  • Press lightly on the nearby wall or ceiling while the ticking occurs to feel for movement. If you can feel a slight shift under your fingers, the pipe is moving against something.

3. Check visible pipe runs and supports

  • Open the cabinet or access panels and inspect visible pipe clips, straps and the dishwasher’s mounting. Look for loose clips or gaps that let the pipe move.
  • Tighten loose straps slightly or replace worn rubber-lined clips with proper cushioned supports where you can reach them.

4. Test after small adjustments

  • After any small tightening, run hot water again and listen during the cool-down. Note whether the ticking is reduced or eliminated and whether the character of the sound changed from sharp to fading.
  • Keep track of what you did and how the sound responded so a professional can act on that information if needed.

    • 5. When you can’t access the run

    • If the pipe run is behind finished walls or a ceiling and the ticking continues, stop attempts to fix it yourself and call a plumber to trace and access the piping safely.

    What Not to Do

    • Don’t wedge rigid shims into cavities or under pipes to stop the sound; that can transfer stress and create leaks or breaks.
    • Don’t spray expanding foam blindly into wall or ceiling cavities to silence the noise—foam can shift pipes, block necessary movement, or hide leaks.
    • If the ticking is near electrical runs or finished ceilings, have a plumber trace the pipe path first rather than poking holes; you could hit wiring or damage finishes.
    • Don’t tighten pipe runs excessively or try to reroute piping unless you are qualified—improper work can cause leaks or code violations.

    When to Call a Professional

    • Call a plumber if the ticking is loud inside finished walls or ceilings, if you feel movement when you press on drywall, or if the sound is sharp and recurring rather than a short fade.
    • Also call if you see any sign of leaking, corrosion, or if the ticking started after electrical or plumbing work. A plumber can trace the pipe path, check support locations, and recommend corrections that protect finishes and wiring.
    • If the ticking is accompanied by banging or pressure surges, have a plumber evaluate the water pressure and the home’s pressure-reducing valve or expansion tank.

    Safety Notes

    • Turn off the dishwasher and, if you will work inside a cabinet, shut off the water to that appliance before doing anything that involves disconnecting fittings.
    • Avoid drilling or rough probing through walls without locating pipes and wires first; cutting into a pipe or electrical conduit is hazardous.
    • If you suspect electrical runs near the ticking, turn off power to the area and call a professional—do not attempt to move or alter wiring yourself.
    • If you detect a leak or feel warm/moist spots, stop using the appliance and call a plumber promptly to avoid water damage.

    Common Homeowner Questions

    • Why does the ticking stop after a few minutes?
      Most likely the pipes have cooled and settled; the movement that made the ticks is finished.
    • Could this be a leak in disguise?
      Not usually; ticking from thermal movement rarely leaks. If you see moisture or stains, treat it as a leak and call a plumber.
    • Is it safe to ignore if it’s just occasional?
      If it’s occasional and fades, it’s usually harmless, but have a plumber check if it’s frequent, loud, or inside finished walls.

For more related articles, see the Ticking or Clicking Sounds During Water Use hub.

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