Set the pressure at the domestic waterworks


A domestic waterworks is characterized by the fact that always water is available. For this purpose, water is stored in the pressure vessel. From this it can be concluded that there is an on and off pressure for the feed pump. For a domestic waterworks, you can set these two print positions. How to adjust the pressure at the house waterwork, you will find in this guide.

Operation of a domestic waterworks

In a domestic waterworks is always ensured that a sufficient amount of water within a certain pressure range is available. Thus, the domestic water plant is an important element where water must be provided throughout.

But if you need a lot of water with a certain minimum pressure, the house water is rather unsuitable. In this case, the house water automat is the better choice. The concrete differences between domestic water boiler or domestic waterworks can be found here.

Switching pressure and differential pressure at the house waterworks

This is the basis for the functional principle. If the pressure falls to a certain minimum, the pump switches on and delivers water again. The pressure vessel is filled with water. An air bag, which is in the pressure vessel, is compressed. Because the contained gas (air, nitrogen, etc.) compresses, when a certain pressure is reached via the pressure switch or pressure switch, the pump is stopped. The pressure difference also defines how much water is stored. The larger the pressure difference is up, the more water is stored.

Adjust the pressures

The respective pressures lie in the following areas:

  • Minimum pressure: between 1.0 and 2.0 bar (switch-on pressure)
  • Maximum pressure: between 3 and 4 bar (referred to as pressure difference)

The respective pressure ranges can be adjusted. For most domestic waterworks there are two adjusting screws on the pressure switch. To do this you must open the plastic housing of the pressure switch. In modern domestic waterworks, these are often a big and a much smaller adjusting screw. The larger screw regulates the switch-on pressure, the smaller screw the differential pressure to this switch-on pressure, ie the maximum pressure, when the pump shuts off again.

Pressure switches are not subject to any standard

Note, however, that this is not a description of a standard device. Theoretically, the two adjusting screws could also work the other way round, but they could also be the same size. You must therefore always look in the control line to the domestic waterworks, as the manufacturer has designed the pressure switch. Now only the pressure is changed by turning the adjusting screws. In particular, if you have a system that is also connected to the public water network, you can adjust the pressure accordingly.

Use the pressure gauge to adjust

Safety (to which pressures the domestic waterworks now switches on and off) is provided by the manometer on the pressure vessel. Watch this closely. You can now read when the pump turns on and off later. Now you can tailor the print exactly to your needs. The recommended pressure for switching on the pump of the domestic waterworks is usually 1.5 bar. Ultimately, that's just a guideline.

Never fall below the minimum values ​​specified by the manufacturer

The marginal pressure data (minimum or switching pressure and cut-off pressure or pressure difference) must be taken into account. Because the pressure vessel consists of the air and the water chamber. In between is a membrane, which also has a defined pressure. This pressure of the membrane in the pressure vessel must not be fallen below. Everything else can lead to damage to the domestic waterworks.

Tips & Tricks

In addition to adjusting the pressure at the domestic waterworks, drawing air is often a malfunction. Under "Domestic water works pulls air" we describe the further procedure in detail. On the other hand, bleeding domestic waterworks is only necessary for systems that are not self-ventilating. Also check the pressure regularly at a domestic waterworks which is in operation. Not infrequently, the pressure is changed, for example, when changing the filter. In order not to permanently damage the domestic waterworks, the pressure should then be checked and, if necessary, adjusted correctly.


Video Board: How to Check and Adjust Pressure Tanks