The OP advised that with city water pressure only (12vdc water pump off I assume) he got hot water flow through taps etc without issue......so that should indicate his connected city water hose, valve etc is also fine. It would help to know how the plumbing lines were actually physically run and connected.......for example, if the city water line is T’d with one output of the T to the hot water tank and the other T output port going to the cold water lines of the coach (water pump output).......then if there was a blockage between the city water T and the pump output line, that would allow hot water flow on city, but no cold water flow on city. The OP advised that cold water in the coach works fine on 12vdc water pump, but the question is, does the hot water flow properly when on water pump only? A complete blockage of a water line seems very unusual ( a lot of plastic debris maybe?).......it would be more likely a pinched line (or valve turned off) in an appropriate water line location. I am wondering if a slide positioning change may also be involved (pinched line) in this issue somehow.......or some other recent coach changes? A good head scratcher for sure.
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