Pump when hook up to city water

I do it when the pressure is low. No problems.

I'm not a hydralics expert, but I guess that if pressure from the pump is greater than pressure from the city line then the pump will send water not only to your tap but also back into the city line! (But maybe there is a valve in the city line that prevents backflow.) Have you tried turning city water off and using the pump only?

I think that you had better keep your freshwater tank topped up, even it takes hours to do so.

RoyF wrote:
I'm not a hydralics expert, but I guess that if pressure from the pump is greater than pressure from the city line then the pump will send water not only to your tap but also back into the city line! (But maybe there is a valve in the city line that prevents backflow.) Have you tried turning city water off and using the pump only?

I think that you had better keep your freshwater tank topped up, even it takes hours to do so.

There is a backflow prevention device at the shore water inlet. Otherwise, every time you turned on your pump you would pump water down the side of the RV. (Mine failed one time when we were on a 6 week camping trip and doing a lot of boondocking. My temporary fix was to get a garden hose shut-off and screw it into the shore water inlet, then turned its valve off. Worked like a champ. When we got home, I replaced the backflow preventer.)

To the OP: There is absolutely NO problem with turning on your pump when you need more pressure. As far as where the water comes from, that depends on the shore water pressure. The lower the shore water pressure, the more water you will get from the tank.

We never use our water pump nor do we put water in the fresh water tank

Am I correct in assuming that the pump would not work similarly for us due to the fact that our freshwater tank is empty?

Gonna try this tonight and see

The pump runs off the tank. Don't turn it on unless there is water in the tank.

Good question about where the water will come from! I've wondered the same, we usually run off the tank/pump only, but lately I've been using the city water hook up more.

I still keep the fresh water tank full, and turn on the pump when showering (other times, who cares if the water pressure is low?). I have not tracked how much water comes out of the tank, I assume it's a split of both depending on the pressure differential.

and smarty, you are correct your pump will not help you out if the fresh water tank is empty.

We keep water in the fresh tank, and use it, even for drinking sometimes. When connected to shore water, we also use the pump occasionally to increase pressure and flow while showering. It is a big improvement for the shower.

The water usage will not split between the city water and pump, it will use water from the higher pressure source. So you will have to add water to your tank from the city if you are staying very long.

City Water Inlet has a 'check valve' so when using pump water does NOT flow backwards theu the city water inlet connection...otherwise when using pump the water would leak out the inlet

Pump has an internal check valve so when using city water source the water doesn't flow backwards thru your pump

With pump switch on (and water in fresh water tank) the pump will NOT run unless the RV Plumbing System pressure is lower then the pump pressure switch Start set point......
With city water connected and pump RUNS the system pressure is low enough for pump to supply water demands and city water flow is static due to inlet check valve going closed due to pump discharge being hogher then city water source (plus inlet check valve has a spring to assist in closing it)

So either City water supplies the RV Plumbing System OR the Pump sucks water from fresh water tank and supplies the RV Plumbing System


Basic RV Plumbing System

"We never use our water pump nor do we put water in the fresh water tank"

Why? So many beautiful dry campsites in the West but you have NO water.