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Tank Top-Up Systems
 
What are tank 'top-up' or mains water 'trickle-feed' supply systems?

Tank ‘top-up’ systems ensure that if levels in the rainwater tank fall to a designated minimum level, mains water (if it is available in the area) is used to 'top-up' the tank with a small volume of water. This minimum water level can be set at any height, however typically will be just above the tank outlet point, so that as much of the tank volume is available for rainwater capture when it rains. This ensures there is always a supply of water in the tank to meet your requirements.

These systems are also called 'trickle-feed' systems and are important when rainwater from the tank is the source of water for internal purposes, such as toilet flushing or laundry use.

How do they work?
The system utilises a valve that when activated will introduce mains water to the tank. When the tank water level reaches a designated minimum level, the weight (suspended by an adjustable nylon cord) pulls on the cord to trigger the valve. The length of the cord can be varied depending on the minimum water level at which you require the tank to be ‘topped-up’. The system is a simple and effective solution and is easily maintained.
 
A simple system that ensures the tank does not empty, whilst leaving the tank volume above the 'top-up' zone available for capturing rainwater when it rains.
 
tank top up image
 

The system from Rain Harvesting Pty Ltd utilises WaterMark® approved components, is housed in a unit on top of the tank and is configured to ensure a visible air gap is maintained between the system outlet point and the water level in the tank when it is full to overflowing. This prevents backflow of water from the tank to the mains supply network and potential contamination.

System configuration
Installation

It is important to note that mains water ‘top up’ systems must be installed by a licensed plumber.

The Rain Harvesting Tank 'Top-Up' system utilises a valve designed to operate at mains pressure, with a minimum operating pressure of 60kPa, which is an equivalent of approximately 2-3L/min flow rate.

Flow rate restrictors which are typically installed to enable a 'trickle-feed' operation are NOT required with a Rain Harvesting Tank 'Top-Up' system because it only tops-up the tank with a minimum amount of water - the ‘top up zone’ is established during installation. At all times the maximum possible tank volume is available for water catchment when it rains.

Tank Top Up logo small
 
Blue Mountain Mesh™
Leaf Eater® Downpipe Rain Heads
First Flush Water Diverters
Rain Filters
Rain Alert
Rainwater Tank Accessories
Tank Level Gauges
Tank Overflow Outlets
Insect Proofing Your System
Tank Top Up System
Auto Tank Vacuum System
Gutter Downpipe Diverters
Safety Hatches
Tank Accessory Downloads
Rain Harvesting Handbook
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