Which Pump to Choose for Using Rainwater from Retention Tanks or Dug Wells?

How to Choose the Right Pump for Your Needs?

Selecting the right pump for using rainwater is crucial for efficient and trouble-free operation. Here you will find answers to questions regarding the specific requirements and functions your pump should meet.

Obligation to Use Rainwater in New Buildings

According to the Water Act, every new building should collect and subsequently use rainwater. This water is usually accumulated in retention tanks or dug wells and then utilised.

Use of Rainwater

Rainwater can subsequently be used for various purposes:

• Garden Irrigation: A suitable pump will enable efficient garden watering, whether manually or through an automatic irrigation system.
• Domestic Use: Rainwater can also be used in the household, for example, for flushing toilets, which contributes to saving drinking water.

Pumps Suitable for Manual and Automatic Garden Irrigation

For efficient use of rainwater in the garden, an ideal choice is a submersible automatic pump. This pump is installed directly into the rainwater tank and is equipped with the following features:

• Integrated Pressure Switch: Ensures automatic pump operation when opening or closing the hose or valve in sprinkler applications.
• Dry Run Protection: Protects the pump from damage in case the water runs out.
• Drinking Water Certification: Allows safe use of water even in the household.

Thanks to these features, there is no need to install additional accessories, which simplifies and reduces the overall installation cost.

WILO - Extract First

For manual and automatic garden irrigation, we recommend the Wilo-Extract FIRST range of pumps, which offer high reliability and performance. These pumps are available in two performance variants:

• Wilo-Extract FIRST 303
• Wilo-Extract FIRST 304

Design Variants

Wilo–Extract FIRST pumps are manufactured in two designs to meet the specific needs of your installation:

• Bottom Suction: Ideal for standard tanks.
• Side Suction with Prefilter (SE): Suitable for retention tanks containing coarse impurities and prevents pump clogging.

WILO - RAIN

Wilo RAIN 1 

For efficient use of rainwater in the household, for example, for garden irrigation or toilet flushing, an ideal choice is a pumping unit with an integrated control system. This unit is installed in the utility room and offers the following advantages:

• Integrated Control System: Automates pump operation, primarily drawing rainwater from the tank and automatically switching to the mains water supply in case of shortage.
• Dry Run Protection: Protects the pump from damage when there is a lack of water.
• Drinking Water Certification: Ensures safe use of water in the household.
• Automatic Mains Water Top-Up: Ensures an uninterrupted water supply when there is a shortage in the retention tank or well.

Use for Toilet Flushing

When using water for toilet flushing, it is necessary to install a 50-litre pressure tank on the pump's discharge pipe. This tank stabilises pressure surges, reduces the frequency of pump activation, and extends the pump's lifespan.

Automatic Operation

The pumping unit operates completely automatically:

• Water Suction from Retention Tank or Dug Well: The unit monitors the water level and primarily pumps water from these sources.
• Automatic Switching to Mains Water Supply: If there is a shortage of water in the tank or well, the unit automatically switches to the mains water supply, ensuring maximum user comfort.

For these purposes, we recommend the Wilo-RAIN range of pumps, which offer reliable performance and a high level of comfort. These pumps are available in three performance variants:

• Wilo-RAIN 24
• Wilo-RAIN 25
• Wilo-RAIN 45

Equipment Levels

WILO-RAIN pumps are manufactured in two equipment levels:

• RAIN 1: Automatic pump control, automatic switching to mains water supply in case of rainwater shortage, monitoring water quantity in the tank using a float, without noise reduction cover, control via buttons.
• RAIN 3: Automatic pump control, automatic switching to mains water supply in case of rainwater shortage, monitoring water quantity in the tank using a level probe, visualisation of water quantity in the tank (water level in meters or water quantity in litres), including noise reduction cover, control via touch display.

Choose the right pumping unit from our offer and ensure efficient use of rainwater for your garden and household!

Choose a Rainwater Pump