Help with fresh water system.Pump runs continuously.

[DKP]

I have a 2012 Lance 1575, single axle trailer, where the water pump (ShureFlo) runs continuously and I reduced water flow from my shower and faucets.
I borrowed a friends know good water pump and when I installed it the problem remained. I also replaced my on demand water heater with a 4 gallon tank heater and just to be sure I bypassed the water heater and the problem persisted.
The strange thing is that when I run the pump I can hear water circulating in the fresh water tank below my feet and yet I never see water in the rig or on the ground.
Is there a check valve in the system other than in the pump? I ask this because I am wondering if most of the flow is bypassing my normal water lines to the faucets and returning to the water tank.
Any ideas are greatly appreciated!
DKP

 

[Holdmybeer]

Ordinarily the onboard water pump is activated when the system depressurizes, ie., when a valve is opened and shuts off when the system pressurizes, all the valves are closed. Could be air getting in or a leak somewhere. To start, check the toilet, all the low point valves, the outside shower if applicable and the water filter ( unscrew the canister and check the gasket).

 

[MemoriesByTheMile]

Does your shower have one of those valves that allow the hot water side to recirculate back to the fresh water tank? This allows for hot water to get to the shower without losing that initial water down the drain.
I don’t have one of those valves but based on what you described wondered if you might.