Basic water system........
Fresh water tank has have water in it.
Pump needs to be primed by turning it ON and opening faucet (Hot/Cold side) to purge air from system
Hot side will take longer due to having to initially fill water heater tank.
Pumps are designed to 'run dry' without damage
City water hook up and pump feed same system.
When using city water connection you should have a water pressure regulator on water supply to control pressure (50#).
Some water supplies can have very high water pressure.
Having pump ON and being connected to city water source will NOT hurt anything.
Pump will only run IF city water inlet pressure is lower than pump 'start' pressure (typically 30#) Pump will shut-off when pressure is above set point (typically 45#) NOTE: Some upgraded pumps have higher start/stop set points.
Enjoy your 'new' RV........it's all a learning curve we have ALL gone thru.
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31