Depending upon your unit, your RV fresh water system will have a gravity fill, a switch over valve or both to fill the tank. Either way, you are able to fill up the fresh water tank using an outside source and have fresh water throughout your trip. Depending upon your unit’s floor plan, the fresh water tank will be located underneath beds, under the dinette or in the basement area near the back of the RV.
When filling the RV fresh water system do not run the fill hose at full speed. Make sure to allow time for the air to come out, otherwise you could bulge the top of the tank.
Once full, take a look at the on board water pump and turn it on. This will start pumping the water through the unit. There could be additional RV fresh water system switches in the bathroom and near the kitchen sink. This pump is an on-demand pump and will turn on when it senses low pressure and will provide approximately 35 PSI, which can be adjusted if needed.
To drain the RV fresh water system you will need to look at the hoses on the exterior of the tank and find the series of outlets used to drain the system. Some newer fresh water tanks have a large drain on the tank itself that can be used to empty it.
When using the RV fresh water system you will not have quite as much pressure as you would with a city fill connection. If desired, you can still connect your RV to the city fill. This will give you more pressure inside the unit and can also be used to top off the fresh water tank as needed.