Yes, it's entirely normal for air to come out of the faucet during the priming process of your RV water pump. When priming, you try to remove any air trapped within your RV's water system. The air bubbles need to be expelled to create a vacuum that effectively draws the water pump into the system. So, when priming your pump, you might observe air and water sputtering out of the faucets until the air is completely purged and a steady flow of water is achieved. This is an indication that the priming process is working correctly. The pump is fully primed and ready for normal operation once the water flow becomes steady without any air bubbles.