Want this question answered?
Yes
presure regulator is on the incoming cold water line
Sounds like a bad/failed water pressure regulator.
No, it uses water pressure.
Mobile homes that are serviced by city water should have a PRV or Pressure Reduction Valve. This is something that appears to be be the owners decision, as I've seen almost equal numbers with or without. -If a home has PolyB pipe this is a necessity.
Yes, because the water you are recirculating is already past the pressure regulator.
That depends where the regulator is fitted.
A water pressure regulator can be found in many of the common department stores. Costco, Walmart and Target are all options to find this for purchase.
IF there is one, it would be where the water is hooked up from the main under the trailer.
I'm not a plumber, but I would look for an adjustable inline water pressure regulator
On the discharge line with the relief of the pressure control back to suction
Normally screwing in the set screw increases pressure loosen less pressure