RV TOILET

That sounds a lot more like the check valve on the city connection is opening and closing rapidly causing the vibration to hydraulically transmitted into the house. The only way I know how to eliminate the vibration is to either remove the check valve or install a pressure tank in the system.

Fill your fresh water tank and disconnect the water supply from the house. Either that or find the vibrating pipe inside the house and fix.

It's water hammer from the sudden closing of the valve on the toilet that's causing a sudden jolt on the water line you're hooked up to on the house. Someone above had it correctly.

I think Wishbone has the answer. I know my toilet can make a water hammer noise that no other faucet in the trailer can match.

The water valve on your toilet is a full flow valve.
Ever notice that your water pump doesn't pulse when you flush toilet but it does when using a faucet?

So when flush your toilet there is full water demand on system.
Your friend is hearing that sudden rush thru plumbing system which is vibrating/rattling due to piping not being properly strapped or their water pressure regulator is causing the vibration.

It's not uncommon.

IF you disconnect your hose and quickly open/close that hose bib so there is a sudden demand on system...probably hear the same vibration noise

I appreciate all the suggestions. But it ONLY happens when I flush the toilet. Not when I run any other water. I changed the vacuum breaker on my toilet. It had a very small leak. I'm hooked right into the septic tank. It's not when I empty my tanks.

Either the washer in her hose bib is loose or she has a vacuum breaker on her hose bib that is vibrating when you use the hose. If she has a frost-free hose bib, it may be a couple of other things.

Bruce

IT should not happen with toilet flushing as that is a MAJOR open valve, but the inlet has a check valve and at low flow it will indeed HUM a bit.

Also, when you close the valve watter hammer can happen. Here is how,,

Water is flowing, It wished to KEEP flowing but, alas, the valve is closed to the sudden stop causes it to kind of back up and crash about.

A bit like cars on the freeway tailigating when somethign happens up front.

The solution is an air chamber, (Called an anti hammer chamber by some) at the end of the line just ahead of the valve.

IN your house, under the sink you may see a short pipe that goes notwhere.. Yup, that's it.

Oh.. Did you know there is a device that takes ADVANTAG of this feature of water? Called a Hydraulic Ram Pump

What it does is let watter pass through, and when it's good and flowing it slams shut the pass throug valve and the flow causes a sudden increase in pressure.. .This sends the water through a check valve into a pressure vessle (Standard well water pressure tank) and from there up to a higher elevation or to your kitchen sink.. This kind of thing has been around since.. .Well long before this 60 year old was born is all I can say.

ScottG wrote:
She shouldn't hear anything unless your keeping the valve for your black tank open - which you don't wan't to do.
She may be hearing her drain percolate as pressure (your tank draining) enters her system.

It's more likely their fresh water plumbing that's vibrating, rather than her sewer.

She shouldn't hear anything unless your keeping the valve for your black tank open - which you don't wan't to do.
She may be hearing her drain percolate as pressure (your tank draining) enters her system.