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Mendocino, California. Delivery all over Northern California. Call or text (909) 259-7837

Free RV manual

How the Fresh Water System Works

City water, the fresh tank, the pump and the water heater. How to fill it, turn it on and keep it clean.

Two ways water gets in

Your RV can take water two ways. The first is a hose from the campground spigot, called city water. The second is the fresh tank, which you fill and then run off the water pump.

On city water you do not need the pump. Leave it off. On the tank you need the pump on, or nothing comes out of the tap.

Hooking up to city water

  1. Use a white drinking water hose. Never use a garden hose or your sewer rinse hose.
  2. Screw a pressure regulator onto the spigot first. Park water can be strong enough to split a fitting inside a wall.
  3. Run the hose for a few seconds before you connect it, to flush out dirt.
  4. Connect to the inlet marked city water, not the one marked fresh tank fill.
  5. Open one tap inside until the air stops spitting and the flow is smooth.

Filling and using the fresh tank

Fill through the inlet marked fresh or potable. Most tanks hold 30 to 60 gallons. The monitor panel shows the level, but the sensors are often off by a quarter, so do not trust them to the gallon.

Turn the pump on at the panel. It will run for a few seconds and stop when the lines are full. If it keeps cycling with every tap closed, you have a leak or an open valve somewhere.

The water heater

Most RV water heaters hold 6 to 10 gallons and run on propane, electric or both. Always fill the heater with water before you turn it on. A dry heater burns out its electric element in seconds.

To check that it is full, open a hot tap until water flows steady with no air. Then switch it on. It takes about 20 to 30 minutes to get hot.

Check the bypass valves behind the heater. They should be set for normal use, not bypass, or the heater stays empty.

Keeping the water clean

Sanitize the fresh tank at the start of each season and after long storage. A common method is about a quarter cup of plain bleach for every 15 gallons of tank, run through every tap, left for a few hours, then flushed until the smell is gone. Check your owner manual first, since some makers give their own ratio.

When to call a shop

Call a shop if you find water under the floor, a soft spot near the bathroom, or a pump that runs with every tap closed. Slow leaks rot the floor long before you see them.

The maker's own manuals

These guides cover how most RVs work. Your own rig may differ, so check the manual for your make and model.

Renting from us? Call or text 909-259-RVDR before you try a fix. We would rather talk you through it than have you guess, and it is free.

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