water pump

[camp104]

I use a 40 psi reg when I hook up to city water. The pressure is always low to take a good shower.When I use the water pump in the RV It is a lot better. My question is if I am using the RV pump and hooked up to city water is the pump taking water from the city or from my RV tank? Thanks Tom

[Old-Biscuit]

STBRetired wrote:
My water pump pressure switch is set at 55 PSI from the manufacturer so I bought a Watts adjustable regulator and a pressure gauge and set the pressure from the city water inlet to 55 same as the pump. Have never had much luck with the $10 regulators that look like a short piece of pipe.

That 55psi is 'shutoff' pressure set point.
Pump 'start' pressure will be ~40psi (typically 15psi lower then discharge psi)

[crasster]

Do you have a failing or too low regulator or is the city pressure just abysmal?

[STBRetired]

My water pump pressure switch is set at 55 PSI from the manufacturer so I bought a Watts adjustable regulator and a pressure gauge and set the pressure from the city water inlet to 55 same as the pump. Have never had much luck with the $10 regulators that look like a short piece of pipe.

[D_E_Bishop]

Old-Biscuit's answer is pretty complete, all I would add is if you have the room, add an accumulator tank on the pressure side of the pump and after the city water valve. It makes it seems like you have higher pressure because the pressure is constant, you don't sense the on off of the pump.

By the way we live just over the Verdugo's from you in Eagle Rock.

[Hank_MI]

If you really want to use a pressure regulator than get an adjustable one. Crank the pressure up to where it matches the output of the pump, your plumbing can obviously handle more than 40 psi. I've used a 40 psi regulator, actually more than 1 now in the trash. Put it on, seems okay and in very short time seems like the pressure has dropped in half.

[Old-Biscuit]

Pump sucks water from fresh water tank

When connected to city water and with pump turned on---pump will only RUN if city water pressure is lower then pump start set point.

If pump runs then city water flow is stopped because pump discharge pressure closes 'check valve' that is part of city water inlet assembly.
Check valve prevents backflow/cross contamination between RV water system and outside water supply system

When city water is being used a check valve internal of pump prevents backflow thru pump into rv fresh water tank.......overfilling it if pump check valve fails

Pump discharge and city water tie into same cold water pluming line/system......which then feeds cold water plumbing and inlet to water heater and then to hot water plumbing

Basic Generic RV Plumbing System

[wildmanbaker]

Your RV fresh water tank, that's the source that feeds the pump intake.