What is a Rain to Mains Water Pump System?

What is the Benefit of a Rain to Mains Pump System?

A rain to mains water pump system helps you make the most effective use of your stored tank water. It allows you to use your rainwater tank supply first and then switch to mains water supply if your tank water is low or empty.

These rain to mains systems ensure you maintain a reliable water supply to your toilets, laundry and other areas with no break in supply during the automatic switch over. You can reduce your mains water usage by as much as 40% when a switch is connected to your plumbed-in rainwater tank.

Continual use of your rainwater supplies means:

• more space in your tank to harvest rainwater when it next rains
• less mains water usage, reducing your water bill.

How do Rain to Mains Water Pump Switches work?

A rain to mains water pump switching device goes by many names including changeover valve or diversion valve but they all practically work the same way. Here are some of the names they go under:

• rainwater harvesting controller
• mains to rainwater changeover valve
• rain to mains changeover valve
• town/tank switch
• tank to mains interconnection device
• auto or manual interchange device
• main switch-over device
• mains water backup system
• diversion valve

The switching device sits between your house pump, your mains supply and your house inlet. It then either automatically detects the tank level of your rainwater tank and switches to mains water if the rainwater tank is low or empty; or you can manually switch between the two water sources.

A backflow prevention device (also known as a dual check valve) must also be installed so that water from your rainwater tank cannot enter (and contaminate) the mains water supply. Backflow prevention devices are available in three hazard ratings: high, medium and low.

What types of rain to main changeover valves are there?

There are two types of rain to main changeover valves which are electronic valves and hydraulic valves. At Water Pumps Now we sell hydraulic valves. Hydraulic valves have no electrical components and function on water pressure only. This eliminates any electrical componentry failure.

Hydraulic valves are easy to install and are suitable for external and submersible pressure pumps.

Are there different types of hydraulic changeover valves?

The Rainpro hydraulic changeover valve comes in two styles with a certified built-in dual check valve for back flow prevention in both models. The RM1600 hydralulic changeover valve suits pump systems with a maximum pressure of 600kPa. The RM1500 hydraulic changeover valve suits pump systems with a maximum pressure 1000kPa.

Should I pick an automatic or manual Rain to Mains Water Pump System?

A rain to mains water switch can be either automatic or manual dependant on if you wish to manually turn your system on and off rainwater or townwater, with some states requiring systems to be automated.

• An automatic switching device detects when rainwater tank is low then switches to mains water. It typically uses either a float switch in the rainwater tank, or detects the rainwater tank water levels based on pump pressure. Because it is automated, it provides you with a continuous water supply but it costs more than a manual switch and requires electricity to run.
• A manual switching device requires you to go outside to your rainwater tank and manually open/close the tank and the mains valve. While manual switches tend to be reliable, cheaper and don’t use electricity, you need to leave the comfort of your home each time you want to adjust your water source.

While a manual device would suit most homes, some states actually require that an automatic rain to mains switching device is installed – such as South Australia and some areas of Queensland. Make sure you check your local council requirements if you are unsure.

If you are looking for an automatic rain to mains switch, we recommend the Reefe Rain to Mains Pump System which automatically manages the switch over. There are set ups for supplying part of your house or your entire house depending on your tank size.