Is there a quiet water pump?

I had a noisy pump in a 5th wheel I had. The pump mounted to the floor so I added a rubber pad under it and I added an accumulator tank. It really quieted things down and at night the stool could be flushed several times without the pump coming on.

Does your RV have a pressure tank in the system? IN my RV the pump comes on whenever I turn on any water. With a pressure tank installed, you could turn the pump off at night and be able to flush the toilet a couple of times and use the tank pressure to supply water.

I had one once that sounded like a Harley at full throttle...

As mentioned above, the water lines can be a contributing factor. One of mine was loose and it banged against a wall with every surge of the pump. Some oversize plastic pipe clamps and some medium density sponge foam around the water line helped a lot. Also tucking that same foam between the water lines and floor / walls too.

In addition to that, my pump was mounted directly to the floor. I removed the screws, got a square of firm, but not rigid foam / rubber and used it as an insulator to the floor.

It helped a lot but the sound will always be there. You can't get away from the sound of the pump itself.

We leave our pump turned off at night, and don't flush until the morning. No big deal there, a little extra liquid in the bowl until morning.

> Is there a quiet water pump?

When it's turned off. :-)

Just trumping here, but you might want to look at the mounting of your existing pump. If mounted solid to a surface, the vibrations of the pump will act just like a magnet in a speaker. Any flex in the lines hooked to pump? If not, the lines can carry the noise, vibrate another "speaker"
Stand of and look at your rig from the side. Is your fresh water tank below the floor of trailer? Is trailer floor below floor of TV bed? Trailer have a gravity fill for the tank, where you can pour water in, or must it be under pressure? Assuming gravity fill, can you slide a hose in far enough to get below the floor of TV? Even if you need a short piece of smaller hose to fit in the fill, just screw together so it doesn't leak. Hose from bottom of transfer tank, into fill. Might need a little air pressure in top of tank (fresh water? Bell, just suck the hose!) to start flow, but siphon can move water pretty easy

Typically it is not the pump that makes the noise, at least not for me. It is the vibration and knocking sounds from the supply lines. That is best fixed with some insulation material.