Water pump very loud.....insulate or replace?

Some are loud and some can hardly be heard. Check your pumps installation to be sure it is done correctly (not to tight to the floor and not too loose) and make sure rubber mounts are in good condition (and present). Be sure the water lines to and from the pump ate NOT rigid lines (PEX tubing makes for a much quieter bump). Be sure that nothing ELSE in the are is against the pump. When I purchased my Rockwood the pump was excessively loud and when I opened up the service bay I found that they had installed the Sub Woofer of my Surround system right up against the pump and it was amplifying the sound throughout the trailer :E Probably someones idea of a joke but it took only a couple of minutes to move it a few inches away and now you have to be standing right by the service panel to even hear the pump.

Good luck / Skip

In addition to other comments this should help. Silencer kit.

The noise usually comes from the lines touching walls or something else. I simply put pipe insulation around mine in a few places and it's very quiet now.

One fix I've read about is to reposition it with a mouse pad or other layer of foam under it. Usually the vibrations on the floor is the culprit. Check it out, as I read that a long time ago, and there might be better/easier solutions.

Popular subject. Search this Forum for `water pump' then search the results for words like `noisy' or `loud' etc. The solutions are there.
BTW when our pump runs one can barely hear it with the TV on.