How to Mount a Water Tank on a Trailer

The freshwater tank in motor homes is isolated from waste water holding tanks.

Most recreational vehicles, or RVs, have three water tanks. The gray water tank is a holding tank for runoff from the sink and shower. The black water tank is a holding tank for toilet flushes. The fresh water tank provides water for the sinks in the kitchen, bathroom and shower. It is isolated from the waste holding tanks. Most motor homes have a dedicated housing area with a covering panel for the freshwater tank. If you are not sure where the dedicated area on your motor home is, check your owner's manual before beginning.

Things You'll Need

• Adjustable wrench
• Flat-head screwdriver
• Phillips screwdriver
• Hose clamps
• Caulk gun
• Silicone caulk

Instructions

1. Park the motor home on level ground and set the emergency brake before beginning. Make sure all external water connections to the RV are disconnected and shut off the main circuit breaker. Prop open the fresh water tank housing panel.

2. Remove the old fresh water tank, disconnecting it from the outflow hose. You may have to use a screwdriver to remove the old hose clamp.

3. Remove the cap from the outflow valve on the new fresh water tank. Put the tank into the housing and connect the outflow valve to the outflow hose in the housing. Secure the connection with a hose clamp over the spot where the hose connects to the valve on the new water tank. Tighten it with a screwdriver until it is snug. Do not over-tighten.

4. Caulk the connection and hose clamp and let it dry.

5. Reconnect the external water connections and turn the main circuit panel back on. Fill the fresh water tank with water and test the connections by turning faucets in the sinks and the shower on. It can take a minute or so for the water to refill the lines in your motor home after you have changed fresh water tanks.

Tips & Warnings

• Before buying a new water tank, open the housing on your RV to check what size fresh water tank you should buy.

References

• RV Basics: RV Water Pump Basics for Motorhomes, Fifth Wheels and Travel Trailers
• RV Basics: RV Gray Water and Black Water Holding Tank Basics

Resources

• Camping World: RV Freshwater Systems