A downpipe filter is installed into a section of down pipe to filter water collected by gutters from your roof. Some devices simply filter the water, extracting dirt and debris (including leaves & moss etc) allowing clean water to flow into your sewer to help avoid blockages. Others also provide a diverter function which is used to fill above ground tanks or water butts.

Filters are essential when using water butts, water tanks or rainwater collection and rainwater harvesting systems. By storing filtered water, it is more hygenic, reduces algae and also stops taps and pumps from becoming damaged or blocked.

Water butt diverters vary in price and specification from basic filters that redirect water from the downpipe to more sophisticated diverters that filter the water, have overflow switches and taps to cease the diverter function. This can be handy if the water butt is being moved or replaced or is sometimes used in cold winter times to avoid freezing water. Most importantly more expensive devices have easy clean features which allow easy access and removal of the filters.

How a Downpipe Filter and Diverter works:

As water passes through the diverter water is filtered(1).

Filtered water passes out of the diverter and into the water butt or rainwater collection tank(3).

Waste/dirty water passess through the diverter and continues along the down pipe(2).

Some of these types of down pipe have easy to remove filters. This typically involves a filter that can easily be removed without having to remove the whole device from the section of down pipe. Filters may need to be removed to be cleaned or clear blockages.

Ejection Downpipe Filter

An ejection downpipe filter is different to a normal downpipe filter as dirt and debries are filtered and ejected from out of the side of the downpipe(6). This has the obvious benefit of little/no maintenance as the filter and waste pipe are less likely to become blocked.

Note that water is not diverted with this type of filter, all clean water passes through the filter. This type of filter is useful when used in conjunction with underground tanks.

Finally, don't forget to choose a diverter in the same color as your drain pipe for a matching finish!