Old-Biscuit wrote:
An accumulator WILL help considerably
A simple accumulator tank solved multiple issues for me. I would not own another RV without one.
The RV system is closed, unlike a sticks and bricks house that usually allow backflow to the city supply to relieve pressure. I have seen the RV system at a static 60psi cold, then started the Water Heater and allowed it to come to temperature without opening any fixtures to relieve the pressure.
I have seen it rise to as much as 140psi regardless of an air gap in the WH or not, this pressure revealed weak spots in my system too. I am sure this is what you are experiencing.
A simple accumulator tank will solve this issue and also provide some additional benefits as well.
Very inexpensive, easy to install and they come in sizes from one quart to two gallons for RV's or more. The bigger the better, I went with a half gallon size due to size constrictions and it works perfect.
Cheers