But if not, to find the best place(s) to add a local arrestor: If it is new construction, there may be a PEX manifold which makes life easy. An arrestor placed on the highest fixtures in the system can have the best effect as long as there is a path from each fixture to the air gap. They are usually installed at each fixture above the valve so that there is the least amount of shock on the line however, a whole house water arrestor can work too as long as it can absorb excess water pressure. Water hammer arrestors work by creating a compressible gap of air that can absorb the shock of the water hitting the suddenly closed valve. To reduce the water hammer effect, there needs to be a different place for the pressure to go. Reducing the water pressure can avoid the noise and may even go unnoticed with today's eco-friendly fixtures, but it is better to add arrestors so it can compress shock. Since water can't be compressed, all of the pressure is transmitted to the pipe as mechanical force when the valve is closed, causing it to knock and rattle. Ironically, it is a problem when the water supply doesn't have enough air, not water. Water hammer happens when there is too much pressure in the line when the valve shuts. I wouldn't expect this to be happening in brand new plumbing, so is it possible the plumbers messed up by not including hammer arrestors in the original plumbing?
#Water hammer arrestor code
It seems to me like hammer arrestors should be part of the code or something. That also has done nothing.Īnyone have any ideas as to what could be causing this and any possible solutions for a whole home issue like this?ĮDIT: I just want to clarify. The one last-ditch attempt I made at a fix was replacing the PRV on the mainline. It seems to be difficult to pinpoint the exact location, as the hammering happens with any faucet in the house that's used (sink, shower, tub, toilet, appliances.) I'm assuming for a water hammer arrestor to work it'd need to be on the main line where the water hammer is actually happening? So he did that and it didn't change a thing. He suggested installing water hammer arrestors on the washing machine. We had a plumber come from the company that built the house. I believe this to be water hammer as I can't think of anything else it could be. Well, I changed the gasket to stop the toilet tank issue but I started noticing that thunking occurs anytime ANY water in the house is run. We had a toilet gasket warp and so the tank would slowly leak, and I started noticing a persistent thunking every time that tank refilled.
![water hammer arrestor water hammer arrestor](https://s7d2.scene7.com/is/image/homedepotcanada/p_1000724511.jpg)
For the first 8 months or so, the plumbing worked great. I am in a newly built house (completed in 2020).