knocking pipes

[kmaz]

Whenever I turn a tap on, or start the washing machine my water pipes makes a creaking sort of knocking noise. They haven't always done this, but have started recently. What could be the cause of this? What can be done about it?

[coolspot]

In our case, it was due to a malfunctioning well pump that caused a fluctuation in water pressure... (possibly air in the water too).

[tallAJ]

air in the pipes, ive had the same issue and it goes away over time or your pipes arent secured.

[dgmorr]

Maybe the basement is cold? I get this if I have the main water valve shut off for a few hours. Usually only the hot pipe does this. It's also possible that the pipes are binding on something, so when the temperature changes, it will rub against that something.

[nornet]

Is the pipe exposed and if so can you see if it is attached to the floor joists or wall for support?

[kixx9o5]

Whenever I turn a tap on, or start the washing machine my water pipes makes a creaking sort of knocking noise. They haven't always done this, but have started recently. What could be the cause of this? What can be done about it?

The pipe is expanding with the hot water flowing through it. It is probably rubbing against a wooden stud. You might need to rip open the area where the noise is and get it fixed by a plumber.

[kasm]

sometimes happens when there is air in the pipes that can't escape. try shutting off the main, draining your pipes by turning on the lowest and highest taps in the house. Close the taps and turn the main shutoff back on.

[kmaz]

Thanks for the suggestions. I can see the pipes, and they are secured but maybe not tight enough. I will also try draining the pipes and see if that fixes the problem.

Thanks again

[midget_man]

I second the draining the pipes suggestion. It sounds like air in the pipes. I always try and Fonzarelli it when this happens, turning them on and off quickly, letting them drain and quickly jerking the tap on and off. Seems to work for me.

[craftsman]

Without actually hearing the noise, it's hard to be sure but it could also be water hammering.

You can pick-up a water hammer arrestor and see if it solves your problem.