When we turn on or off either hot or cold water any where in the house, there are loud hammering like noises coming from around the water heater...

We are on a well in the county, pressure is set to 20/50, new well, new pump, built house 3 years ago and have had same noises all along...

Any ideas??

Is your water heater gas or electric? My bet's on gas. Tom

I had the same problem in an apartment I was renting. I had someone come out and I was told that it was a build up of sediment in the bottom of the tank that was causing that noise.. every time the water would heat up the sediment would pop or crackle..

Concerned, that was probably correct in your situation but this person says it happens with the cold water too. Looks like Speedball1 is heading in the same direction by asking about the heater. I don't have this figured out and the OP has not answered Tom's question. This isn't a crackle but a water hammer. However a true water hammer does not hammer when the water is turned on, only when turned off. I am just wondering if the information we currently have was stated correctly.

Ballengerb1... you are correct... only happens when the water is shut off. House is all electric. Thanks!

OK, give this a try but it may take several minutes per valve. First close your main supply and then go to each offending faucet. Under the sink hopefully you will find a stop valve that can be opened and allowed to drain. Drain the supply going up to the sink and the supply coming from the wall, this will replenish the trapped ai needed inside the arrester in the wall space. Once each stop has been opened and drain reconnect them all and turn on your main. Inspect each valve for the next few minutes to make sure you did not start and new leaks. Speedball shared with me that he sometimes pays a piece of toilet paper on the flooir, just one little drop will really show.

Thanks! Will try it. By the way, the noise seems to be coming from our water heater.