A protective backwash filter
the access barrier against dirt

It is sometimes said that cartridge filters are more environmentally friendly than backwash protective filters. The reason given is that water is consumed during backwashing.

However, if you make a thorough comparison, you will quickly see that this calculation does not work.

Tens of litres of water are used to manufacture and transport a replaceable filter element, including foil packaging and cardboard – many times more than what flows into the sewage system during backwashing. Not to mention the energy required for production and transport.

In addition, a small mountain of waste accumulates with every filter change. And this at least twice a year, because filter cartridges must be replaced at least every six months for hygienic reasons (according to EN 806-5, A).

There are basically two types of drinking water protective filters: cartridge filters and backwash filters. In the case of cartridge filters, as the name suggests, the filter insert must be replaced regularly. Backwash protective filters are cleaned simply by reversing the water flow.

To say it in advance: The valid standards and guidelines do not give any recommendations as to which design is preferable.

In Spain for example a backwash filter is mandatory for drinking water.

A disadvantage of cartridge filters is that their owner must take care of changing and re-ordering the filter elements. In addition, replacing a filter screen generates a lot of waste – from the used filter element to the product and shipping packaging. In the case of the backwash protective filter, this is offset by the amount of water consumed during backwashing.

Another problem with the cartridge filter is that the homeowner has to deal with parts that come into contact with water. This is basically a hygiene risk. In addition, the water supply must be interrupted to change the filter. This is not allowed in Spain, for example.

A plus point that backwash protective filters can bring into the field: In the automatic version, these protective filters simply do the cleaning themselves. The automatic backwash protective filters of the JUDO germ protection class, for example, use various parameters to calculate when backwashing is due and carry it out independently. This means that the owner does not even have to go to the basement. And still he can be sure: His filter is cleaned efficiently and always at the right time.

As the name says: An automatic backwash protective filter carries out the cleaning of its filter screen independently. The use of such a filter is always useful if there are no fixed responsibilities for the drinking water installation and nobody feels directly responsible for backwashing the filter. This is often the case in apartment buildings, for example. An automatic backwash protective filter ensures that no backwashing is forgotten and that the filter is in a hygienically perfect condition.

Of course, such filters are also suitable for single-family homes – if the owner appreciates the convenience of a self-cleaning filter.

German DIN 1988 prescribes a DVGW-tested protective filter, regardless of the pipe material. However, complete protection is only given if the protective filter has already been installed before the drinking water installation is filled for the first time.

New, bare metal pipelines are particularly susceptible to pitting corrosion. In addition, it is precisely when commissioning a new drinking water installation that the risk of dirt particles entering in is greatest.

If the protective filter is installed afterwards, particles may already have been flushed in. However, by installing the protective filter, you can prevent further dirt from entering the installation. So it is never too late for a high-quality protective filter.

A very unhygienic matter – especially when you consider that water is our most important foodstuff. Dirty filters provide an ideal environment for life for dangerous germs. They can even pose a health threat under certain circumstances. You can backwash a backwash protective filter yourself. If it is a cartridge filter, you should ensure that the filter insert is replaced.

If you live in rented accommodation, it is best to contact your landlady. She can tell you what type of filter is installed and whether you can backwash it yourself if necessary. You should backwash the filter at least every six months. This interval is provided for by the standard EN 806-5, A. JUDO recommends to clean protective filters by backwashing every two months.

According to the standard, the filter cartridge of a replaceable filter should be replaced at least every six months. If your landlord cannot provide information on this, you should contact a local sanitary installer. He will be happy to advise you – even if you are a homeowner yourself, of course.

A tip: For apartment buildings, it is recommended that you have an automatic backwash protective filter installed. Such a filter cleans itself. It is therefore the best choice in houses where nobody feels responsible for the drinking water installation.

Your modern fittings and appliances, such as washing machines and dishwashers, are becoming increasingly sensitive. Foreign particles can, therefore, quickly lead to malfunctions. Shower heads and aerators can become clogged.

Your drinking water installation is also at risk: In installations made of metal pipes, dirt particles can cause so-called spot corrosion. Spot corrosion, also known as pitting corrosion, is a form of corrosion that occurs at individual small points and leads to pipe bursts without “notice warning”. The reason: Among the solid particles that have settled in your drinking water installation, a locally limited electrochemical reaction takes place, which can lead to pipe breakage after a short time.

There are basically two types of drinking water protection filters: cartridge filters and backwash filters. In the case of cartridge filters, as the name suggests, the filter insert must be replaced regularly. Backwash protective filters, on the other hand, are cleaned by reversing the water flow.

EN 806-5 regulates the frequency of inspection and maintenance under Appendix A, Table A 1: An interval of six months applies to backwashable and non-backwashable filters from 80 μm to 150 μm. Depending on the contamination of the drinking water with particles, the intervals can also be shortened.

Heavily contaminated filter screens promote the growth of microorganisms. These germs may enter the drinking water installation in an uncontrolled manner. In addition, clogged filters can cause significant pressure losses, so that higher taps are no longer properly supplied.

It is therefore extremely important to check the drinking water protective filter with the necessary regularity. And, if necessary, at least every six months, rinse or change the filter screen.

An automatic backwash protective filter is recommended in apartment buildings. It flushes itself regularly – and thus ensures that no cleaning is forgotten. The manual protective filters of the JUDO PREMIUM- and PERFORMANCE-LINE up to connection size 2″ have the JUDO call function as standard, which reminds the operator of due backwashes via app.

Depending on requirements, DIN-DVGW-tested cartridge filters, backwash protective filters or domestic water filtration stations are used.

Cartridge filters are the simplest variant. As the name suggests: According to the EN 806-5 A standard, the filter insert of these filters must be replaced at least every six months. During the replacement process, the water is shut off. The water supply is thus briefly interrupted.

With backwash protective filters, there is no need to replace the filter insert. Although these protective filters are somewhat more expensive to purchase, you can easily remove particles from the screen yourself. The water supply is not interrupted. The standard also stipulates an interval of six months for backwashing. JUDO recommends that such filter cleaning should be carried out every two months.

Automatic backwash protective filters are available for more comfort. Such a filter carries out the backwashing independently – as owner you have even less effort. An automatic version is also suitable for apartment buildings, as experience has shown that protective filters are often neglected there.

If backwash protective filters are equipped with an additional pressure reducer, they are referred to as a domestic water filtration station. The pressure reducer compensates for pressure fluctuations and thus protects household appliances and fittings. In addition, a domestic water station can also reduce water consumption.

The drinking water protective filter is installed directly behind the main water meter. From the water meter onwards, it is no longer your supplier who is responsible for the water quality, but the owner or operator. Other devices for water treatment, such as a softening or dosing systems, find their place after the protective filter.

Your plumbing installer has the experience and the necessary expertise to install such devices quickly and without great effort. For hygienic reasons, he should wear protective gloves if he comes into contact with water-bearing elements such as the filter insert.

The quality of our drinking water may be absolutely perfect. The waterworks ensures the quality of our most important foodstuff with countless tests and controls. But for all the care taken: no one can monitor the drinking water until it reaches your kitchen and bathroom.

The way from the waterworks to the tap is long – 10 km or more are not uncommon. The longer the distance, the more likely it is that drinking water will carry rust products and deposits from the pipe walls and bring them into your domestic water pipe. This also applies to dirt that may be introduced into the water pipe during repairs to the pipe network. Small particles that can cause great damage in your domestic water installation.