Losing pressure on water system

If you have an outside shower that's the first place I would look - many people who have them (including me) have removed because they can be a chronic source of leak issues.

I've had this happen several times thru the years, and different RVs, and every time it fixed itself. If it doesn't annoy you badly, let it be it'll probably go away.
Just make sure there are no leaks.......except back to the tank

Leaks do0n't HAVE to be inside the RV. Check around the water heater pop off valve and the drain plug for signs of seepage. It could also be leaking out the pressure water connection if the check valve is not holding well there. Another outside leak is the dog shower and even better hidden, the low point drains could be leaking.

Doesn't HAVE to be a leak inside of ourside to loose pressure because it COULD be bleeding the pressure through the water pump into the non pressurized water tank. They can be time consuming to check and locate the problems but I'd recommend you begin with the items that don't cost anything or can easily be seen and work your way up to the more costly items.

Good luck / Skip

Common things that make pump run with faucets closed

Leaks: fittings, toilet, water heater press. relief valve dripping, outside shower, low point drains

pump internal check valve leaking back to tank

city water connection check valve leaking

Wow, thanks for the replies. I'll dig into it just as soon as I can. Thanks!!!

I agree with that.

Yes, but not lately. Your pump has a type of valve that keeps the water from flowing back into the water tank once the pump has built up pressure. If there are no visible leaks, it is probably an internal leak in the pump housing. It's fairly simple to take the pump head apart. You will probably see a small spring type plunger that pulls open when the pump is running. when the pump stops, this plunger is forced back. If you will give the pump type and model, someone else who has worked on a pump of your type probably can give you more info. Good luck.

I think there was a similar problem posted recently, it turned out to be a check valve that malfunctioned. Do you have a check valve near the pump?