Move into this home 10 years ago.

Only time I ever heard noise in the pipes was when the yard sprinklers switched on. When any yard valve opened to water a section of the yard, I'd hear a constant tap-tap-tap-tap until the system shut off.

No other noises in house when turn on/off hot or cold taps, ice maker, dish washer, wash machine.

6-months ago, I replaced a leaky shower valve in the master bath. Just replaced the valve internals. Shut off the whole house water when I did this, but as I got into it, found there were actually isolation valve at the valve box I could utilize (which I did 2nd/3rd time I messed with it). I had to take it out twice after I first replaced it. Once b/c I had it backward (cold was hot, hot was cold), then later I learned that it was leaking b/c I did not put silicon grease on the fittings. Shower valve is in a works now, no leaks.

Ever since then, when any water device, cold or hot, comes on in the house I hear a rattle in the wall (pretty sure right behind the replaced shower valve box). If I turn on a tap slowly, no noise, but if I turn on a tap quickly, or dishwasher or washer come on/off, I hear a banging noise in the wall. Note, this is a different noise than when the sprinklers come on. Happens with hot or cold water taps.

I turned on every valve in the house (except dish washer and wash machine), then closed the main house valve in the basement. I also opened the system drain valve ~1-foot above the main house valve to drain the system. I then slowly turned on the house valve to try and fill the system and get out any air. Let it run for a bit, then walked thru the house and turned off each valve from lowest to highest/furthest away. Noise is still there.

Any suggestions? Maybe buy a gauge and see if I have excessive pressure in the system and need a PRV? Doesn't seem likely since there were never noises before.

I have a similar issue but it's only on the hot water on one side of my house and only when it's cold. Likely always hammers, but when it's not cold and dry the pipe doesn't slam against 2x4s. Seems like a wild goose chase to me.

I'll try that, but it's kind of odd that I never heard noises before, now after replacing a shower valve suddenly every fixture in the house causes noises.

Of course!
Especially true if replacing a washer, as the new ones have valves like guillotines ON-OFF, not gradual as the older models. Water hammer is water slamming against a guillotine valve "wall" and the pipes react violently, even the secure ones will MOVE and eventually wear-tear problems may exhibit.

Ben is spot on and VERY EZ to do.

Right field thoughts: Air may have leaked into the pipes during the replacement that may not be THE cause but certainly would exacerbate it & this too will pass w/arresters.

After getting frustrated with the new off brand shower valve (it would leak in full off position but if you turned it partly on it would not leak, but not always) and dealing with it for several months, I just paid for the $70 OEM part, replaced it Friday afternoon and the noises are gone!

All I can think is something in the valve was allowing some kind of back siphon or air into the lines and that's what was causing the noises.

Should have just bought the OEM part to begin with. The Home Depot branded part had mixed reviews, but I figured if it worked for $12 then why not. Also, I sort of needed it right away (the old one had cracked and was leaking constantly out of the shower head) and it was several days for the replacement and wife prefers her shower to the guest room.

EDIT: I did try the water hammer arrestors on the wash machine but nothing changed.