The HydroMax RV Fresh Water Pump - 12 Volt - 3 Gallons Per Minute at 55 psi, # P25201 is a good option. This can be positioned either vertical or horizontal orientation and has a built in check valve to prevent back flow. This is installed using standard half inch diameter hose making it a good replacement option for any OEM pump that has an approximate flow rate of 3 gallons per minute. view full answer...