Rainwater collector for your overgrounud rainwater tank

No, a rainwater collector does not automatically fit every downpipe, as the diameter and shape vary depending on the model. Round downpipes in Germany usually have a diameter of 70 to 100 mm; smaller pipes from 50 mm upwards require special models (e.g. the ‘Füllautomat Mini’); there are separate variants for square downpipes. Before purchasing, you should therefore measure the shape and diameter of the existing downpipe and compare them with the technical specifications of the relevant rainwater collector model. The distance between the wall and the downpipe also matters, depending on the model, as a certain amount of space is required for installation.

German detached houses typically have a DN 100 standard, whilst in the garden the size may range from DN 70 to 100. To be sure, measure the internal diameter of your downpipe. Our Speedy and Rapido rainwater collectors are compatible with pipes ranging from 70 mm to 100 mm.

Square downpipes require special rainwater collectors designed to fit the relevant pipe dimensions. At Garantia, you will find the following products for this purpose:

• Downpipe filter Quattro Grey
• Rain collector Rapido Quattro

In most cases, a rainwater collector can be easily retrofitted to an existing downpipe without any prior knowledge. To do this, either a small hole is drilled into the existing downpipe (as with the Speedy, Speedy Flexx and Rapido models) or a suitable section is sawn out and the rainwater collector fitted in its place. It is then connected to the rainwater butt via a hose. No additional specialist tools are usually required; installation takes around 5 to 30 minutes, depending on the model and installation situation. Take a look at how to install the Speedy downpipe filter.

Once the overground rainwater tank is full, any further rainwater flows directly down the downpipe. This prevents any more water from entering the tank and stops the rainwater tank from overflowing (unlike when a rain flap is used).

To ensure optimal performance, the rainwater collector should be installed at the same height as the highest water level in the rainwater tank. The pipe leading to the tank should run straight and horizontally.

The required distance depends on the specific rainwater collector and its maximum hose length, but should generally be kept as short as possible. The rainwater tank should be positioned as close as possible to the downpipe so that the connecting hose can be laid short, without kinks and horizontally. This ensures that the rainwater flows unhindered and reliably into the rainwater tank.

A rainwater collector mainly traps leaves, moss and coarse dirt particles. Very fine pollen or fine suspended particles may find their way into the rainwater tank. However, this water quality is sufficient for watering the garden.

A rainwater collector does not usually need to be dismantled in winter, but it should be set to the winter position and emptied before the frost sets in. This prevents water in the system from freezing and causing damage to the rainwater collector, connecting hose or rainwater butt. In addition, the connected rainwater tank should also be emptied, and the inlet or drain plug opened, to ensure that any residual water in the tank or pipework does not freeze and cause cracks.

A rainwater collector with a filter automatically collects rainwater whilst reducing the amount of dirt in the rainwater tank. Leaves, moss and other coarse particles are trapped as the water flows in. This improves water quality, reduces the need to clean the rainwater tank and makes it easier to use the collected rainwater. This is also the major advantage over a rain flap, as with a rain flap the water flows into the rainwater tank along with any dirt.

There is no one-size-fits-all answer to this question, as it depends on many external factors. Generally speaking, it is important to check the rainwater collector regularly. How often this should be done depends mainly on the amount of leaves, flowers and dirt in the surrounding area. As a rule, it is sufficient to remove the filter insert once or twice a year – for example, in spring and autumn – and clear it of any build-up; however, in areas with lots of trees, it is advisable to check it more frequently, several times a year, particularly in autumn.

It is not possible to state a universal water yield for rainwater collectors, as this can vary depending on local conditions. The following factors, for example, play a role in achieving the optimum water yield:

• the degree of contamination in the rainwater
• the position of the rainwater collector within the downpipe
• whether the filter is regularly maintained/cleaned

There may be various reasons for this. First, check that the downpipe filter is fitted correctly. The filter should fit snugly all the way round the downpipe.

Next, check the alignment of the downpipe. If the downpipe is tilted slightly to one side, rainwater may tend to run down that side rather than being distributed evenly around the circumference.

The orientation of the roof and the layout of the downpipes can also affect water drainage. You should therefore check whether a similar volume of water is draining from all downpipes or whether certain areas of the roof are bearing a significantly heavier load.

Points to check:

• Is the downpipe filter fitted correctly and tightly against the downpipe?
• Is the downpipe aligned straight or tilted to one side?
• Is the rainwater distributed evenly across the existing downpipes?
• Could the roof pitch, roof orientation or structural conditions affect water drainage?
• If a filter is fitted, it should be checked regularly for blockages.