GRAF Platin Direct Rainwater Harvesting System – Shallow-Dig Tank, Pump & Mains Back-Up, 1500–7500 Litres

Price range: £2,393.65 through £4,089.79 inc VAT

The Direct-supply system is designed to support WCs, washing machines, irrigation and outside cleaning purposes.

SKU: N/A

Rainwater for your toilets, washing machine and garden

The Platin Direct system collects the rain that falls on your roof and stores it underground, then pumps it to your toilets, washing machine and outside tap. It can also be used for garden watering and outdoor cleaning. It’s a complete package for homeowners, self-builders and installers: tank, filter, pump and mains back-up, chosen to work together.

How it works

Rain runs from your downpipes into one pipe and into the tank. On the way in, it passes through a filter that keeps leaves and debris out. A pressure-sensitive submersible pump sits in the tank and draws water through a floating intake.

This is a direct supply system: the pump sends rainwater straight to your toilets, washing machine and outside tap when they need it, rather than filling a header tank in the loft first. When you flush a toilet or open a tap, the pump starts and supplies water under pressure; when the tap closes, the system re-pressurises and the pump switches off. The pump restarts automatically and has dry-run protection.

Mains back-up for dry spells

In a long dry spell the tank can run low. The mains back-up (Mains-on-Tap) unit, fitted inside your home, then tops up the underground tank with mains water so your toilets and washing machine keep working. A float sensor in the tank tells the unit when to do this, and it adds only the amount of mains water needed. The unit is quiet and small enough to fit in a kitchen or utility cupboard.

See what happens when the tank runs low: What happens during periods of no rainfall? (video)

Choose your size

The Platin is a shallow-dig tank: it’s wide and low rather than tall, so it needs a shallower hole than a traditional upright tank. It’s made from 100% recycled plastic and is installed with gravel backfill rather than concrete, which makes installation simpler and saves around £60 per cubic metre. Platin tanks are trusted across Europe for their reliability in rainwater harvesting.

Capacity Length Width Height to tank shoulder Weight
1,500 litres 2,100mm 1,250mm 700mm 80kg
3,000 litres 2,450mm 2,100mm 735mm 170kg
5,000 litres 2,890mm 2,300mm 950mm 240kg
7,500 litres 3,600mm 2,250mm 1,250mm 360kg

All sizes have an 800mm tank dome with a 315mm dome collar. Choose a pedestrian lid for lawns and garden areas, or a vehicle lid if the tank will go under a driveway.

Images are for illustration; components may be upgraded or replaced with equivalent alternatives.

What’s included

  • Platin shallow-dig tank (1,500–7,500 litres) with dome and DN 100 sealing set
  • Platin telescopic dome shaft Mini (green) with PE lid, for pedestrian or vehicle loading
  • Platin filter package 3 House: Minimax internal filter, inflow stilling system and overflow siphon (DN 100)
  • Home Direct pump package (submersible pump with floating water intake)
  • 25m roll of rainwater pipe (25mm, with fittings)
  • Mains back-up (Mains-on-Tap) unit
  • Float sensor, connecting the mains back-up unit to the underground tank

What you’ll need to supply

  • 100mm duct pipe for the float sensor cable, the pump’s power cable and the mains water pipe to the tank
  • 100mm drainage pipe from your downpipes to the tank inlet
  • 100mm overflow pipe from the tank to mains drainage or a soakaway

It's essential to inform your local water authority before starting any work. According to the Water Supply (Water Fittings) Regulations, installing systems like rainwater harvesting is considered a "material change of use" of your premises. This means you must notify your water undertaker in advance and obtain their consent before beginning the installation.

To notify your local water authority, you'll need to provide details such as your name and address, a description of the proposed work, and specifics about the location and intended use of the premises. Many water undertakers have their own notification forms available on their websites. It's important to use these forms, especially when submitting electronically.

By following these steps, you help ensure that your rainwater harvesting system is installed safely and in compliance with regulations, protecting both your water supply and the broader public system. For any further guidance, please click here.

Platin Tank Dimensions & Weights (1500L – 7500L)

Rain Water Flat Tank 1500L Platin | Download
Rain Water Flat Tank 3000L Platin | Download
Rain Water Flat Tank 5000L Platin | Download
Rain Water Flat Tank 7500L Platin | Download

Platin Tank Levels & Invert Levels

Platin Tank Levels | Download

Platin RWH Tank Invert Levels | Download

Mini & Maxi Lid Dimensions

PE Mini Lid (Pedestrian Loading 371010) | Download

PE Maxi Lid (Pedestrian Loading 371011) | Download

Vehicle Loading Lid (371052) | Download

Extension piece options


Extension Sleeve (371003) | Download


Extension Sleeve (371015) 1000mm | Download

How Self-Builders Future-Proof Their Home with a GRAF UK 5000L Direct Rainwater Harvesting System

This informative guide covers the following:

  • Loading information
  • Tank coverage heights
  • Excavation dimensions
  • Technical & general data
  • Installation & Assembly

Read the Guide | Download
Read the Guide (Tank Only) | Download

Delivery to mainland UK is included in the price, typically within 5–7 working days. Extra charges may apply for Cornwall, mid and northern Scotland and the islands. Tanks arrive strapped to a pallet for off-loading by forklift or slings.

You may also like…