I don't know if this is new or if it's always been there. Never noticed it before.

Whenever I flush one particular toilet, after the toilet finishes filling, I get some noise at what seems like the washing machine water pipes.

Webz seems to suggest that this might be water hammering (again, dunno if this has always been there or something new). If new, is something happening at the toilet - perhaps the toilet fill valve is not closing as slow / smoothly as it used to and should be replaced?

If something that has always been there, just not notices, what's the recommendation? I see there is something called an arrestor. Is this the way to go? Installed at the toilet (one line) or at the washing machine (both hot and cold lines)? If so, any recommendations for brand / model?

Other recommendations?

No other faucet or toilet seems to cause this - only this one particular toilet. I believe this is something new and hasn't been there before which leads me to believe that the toilet fill valve is failing in some manner. But I dunno, I'm not an expert.

Thanks!

Water hammer can be caused by excessive water pressure. Get an inexpensive screw-on water pressure gauge at the hardware store and test it at an outdoor hose spigot to check your pressure. Normal is 40-60, and anything over 60 is excessive.

https://www.homedepot.com/p/Wa...ge-DP-IWTG/100175467

Most houses will have a pressure regulator to step down from the 100+ PSI of the water supply at the street to ~50 PSI for in home use. Over time, the regulator can start to wear out, which can cause your home's water pressure to rise until it's excessive and it starts to affect your pipes and appliances. They usually last ~15-20 years before needing to be rebuilt or replaced.

I had this at my last house, and the initial symptom was starting to have water hammer from flushing one particular toilet. Come to find out my pressure was too high and my regulator needed to be rebuilt.



Or, if your water pressure tests fine, you could try installing a water hammer arrestor on that particular toilet's supply line. I got mild water hammer from my washing machine in my new house, but a hammer arrestor corrected it.

Sioux Chief makes several different types of residential "Mini-Resters", with different sizes and types of attachments. Find the one that matches your toilet water supply line size and connectors, which is probably their 3/8" connector 660-GTR1:

https://www.amazon.com/MINI-RS...0-GTR1/dp/B008RI63BW

https://www.siouxchief.com/Products/ClassDetails/134

Thanks!

We've always had normal to low water pressure. House is elevated above street level. Street level is about 60psi. House spigot is about 50psi. It's monitored by the moen flo device but I'll double check w/ a gauge at the spigot. But if it's house level, wouldn't all toilets cause the hammering, not just the one toilet? Sounds like in your case, just one toilet....

I'll check the pressure. Also, replace the toilet fill valve. If issue persists, then I'll look into one of the arrestors you mentioned. Thanks for the recommendation.

Check your mechanical room where the street water shutoff is. Depending on locality, it's typically code to have a pressure vessel with compressed air that keeps the water hammering / hydraulic pressure at bay to protect your house plumbing supply and is functionally an air spring (like your car tires). If you've got one (looks like a small blue propane tank and has a Schrader valve on it just like your car wheels). It should have a listed air pressure setting and it's likely not in spec.

Thanks all!

Replaced the fill valve. At the moment, no leaks, no hammer. Toto is back in action and good to go.

FYI: I'm getting about 3 years of life per fill valve. Seems kinda short but not sure what's expected across the industry.

This is likely the result of a countdown timer tied to a catastrophic detonation of the entire system. At 12:01 AM on the day following the final payment on your mortgage the system will self destruct. Commence all emergency mitigation protocols and initiate contingency plan now, before it's too late! Time is of the essence...

Ha. You laugh but the house is about 25 years old and nothing has ever been replaced. Water heater, AC/Furnace, kitchen appliances. Well, washing machine has been replaced, that's about it. Bets on what's first to pop smoke?

$20 on the roof.

$40 on HVAC.