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How to Fill a Fresh Water Holding Tank – Fill Dish Installation Instructions

What is a fill dish?
The fill dish is located on the outside of your unit so that you can easily add water to your tank without the need of opening a compartment or climbing under your unit. You can find the fill dishes in the Plumbing Category.

For adding water to the Water Tank you need a Gravity Fill Dish, the hose rests in the port it does not screw onto the port this allows you to place a garden hose into the Gravity Fill Dish port without making a sealed connection so the supply is not pressurized.

For using Water Directly from a garden hose you need a City Fill Dish, the hose makes a sealed connection and the water supply is pressurized, you can not hook this to your water tank and you do not need to go through your water pump.

We carry Gravity Fill Dishes, City Fill Dishes and Combo Fill Dishes that have both gravity and city, the benefit of having both is you can have a water tank of fresh water but if you go to a location that supplies pressurized water (campground – fair – etc.) you do not need to use your water tank supply of water you can simply use the water provided. Be sure to look at the provided example plumbing diagram for more reference.

How to fill water tank - gravity and city fill dish

Visit our Water Fill Dishes Category under Plumbing.

Basic Plumbing Diagram - Example Only

For my application I am not using a fill dish.

For gravity feeding you can place a larger fitting such as a PVC elbow in the tank and allow your hose to rest in this when filling, do not make a secured/sealed connection as this would then be pressurized.

Fitting Cap Example for when not using fill dish

You will still need to vent the tank, this can be as easy as placing a fitting with a screen secured over it. Be aware that if you overfill the tank the excess water will exit the vent fitting, placing the vent fitting overflow to an outside location is recommended. Be sure to screen over the vent fitting overflow to prevent anything from entering the tank. Do not over-tighten fittings as damage will occur.

Examples of Items to Vent Tanks – We do not sell these products they can be found online
Oatey® 1.5 in. NPT ABS In-Line Vent
Straight, Black Plastic Tank Vent

Oatey® 1.5 in. NPT ABS In-Line Vent

What fittings will I need for my plumbing?

We are not aware of how to set-up your tank, set-up will vary by each application this is something you need to research. Have a certified technician install all parts to prevent product damage and personal injury. Please view our Plumbing Category for information on loose fittings we carry. Be sure to Sanitize Tank before installing. It is recommended to use plastic NPT male fittings with plastic female NPT fittings to avoid damaging the threads, metal thread fittings can crush the plastic threads. Very little, if any, pipe thread tape is needed using too much pipe tape will damage the threads. We do not recommend pipe dope as you can not remove the fitting later, if used be sure to use a food safe brand. Do not over-tighten fittings as damage will occur.

For my application I am going to use a pressurized line to the tank.

This will void any warranty on the tank. Turning a garden hose on half way does not work because you can control the amount of water flowing but not the pressure in the line, leaving the tank to fill risks exploding the tank.