I have a slight vibration only in the cold water line in my basement. When I release the pop-off valve, it stops. Is this telling me my water heater is bad?

Hi Duke...

This does NOT indicate that your water heater is going bad.

If this is a gas water heater, it could indicate that you haven't flushed the water heater in a long time.

It could also indicate that you have an issue with a water softener (if present), or even a pressure regulator issue.

It is hard to say without more information on this.

Please take a few minutes and follow the cold water pipe and see if you can isolate the vibration better. If you still find it isolated to the water heater then I would recommend that you power flush the heater by attaching a hose to the drain and opening the drain valve to flush the heater for 5-10 minutes (keep water on to the heater).

Let us know what you discover, OK?

Mark

I flushed it and still ,it vibrates. When I shut the inlet valve to the heater, it stops vibrating. Would'nt this indicate water heater problems.

What kind of nipples do you have on top of the water heater? Do they look like aluminum nipples ? If positive than you have the ones with back flow preventing device built in. I would remove them and installed regular nipple. See if that helps. There is a plastic ball inside each of them and that ball has tendency to vibrate when water flows around it. Back to you. Milo