Recently a plumber replaced the flexible copper tubing on our hot water heater to solid copper piping, alongh with a potable water expansion tank. This tank is on the outlet side of the hot water pipe. Since this time, I hear continuous sound emanating from the hot water tank. Maybe expansion and contraction within the tank? I don't know. I'm trying to figure out what to do.

Do you have a gas or electric water heater? Tom

I have a gas water heater. I was thinking I need to drain it since I've never done this for the 5+ years I've owed the heater. However, the plumber who did the work drained it. Does it need to be drained a few times to clear out all the bilt up sediment at the bottom?

If you do not flush,(not drain) your heater on a regular basis it will build up mineral on the bottom of the tank. When the flame comes on it turns the water trapped under the mineral to steam and the steam escaping is what you hear. Let me show you how to flush your heater. Attach a hose to the boiler drain at the bottom of the tank. With the pressure on, open the boiler drain and let it run until the water runs clear. You will see a spurt of red,(rust) and some white grains,(lime or calcium carbonate). The whole thing shouldn't take more then a few minutes. Don't forget to flush it out every month. Your heater will thank you for it. You might want to consider cleaning the screens on your areators if you have a high mineral buildup. If thev problem still persists after you have flushed, you will have to drain the heater, remove the boiler drain and go up in the bottom of the tank with a wood or plastic rod, (not metal) and try to break up the mineral and flush it out. Good luck, Tom

But do I really need to flush the tank again? It was just done.