Domestic waterworks

Domestic waterworks are suitable for automatic pumping of water from shallow wells, but also for boosting and maintaining water pressure in the water supply system. There are available traditional products (a pump and a pressure vessel), as well as modern solutions fitted with a frequency converter, which are able to maintain a constant water pressure and save energy.

Domestic waterworks are an ideal solution if you live in a house with its own well or you need to stabilize the pressure in a building connected to the water mains. It is a device combining a self-priming pump, a pressure vessel, a manometer and a pressure switch, which is primarily designed for pumping water from a well and maintaining a constant pressure in the distribution. For this reason, it is also suitable for systems with fluctuating pressure, or for multi-storey buildings, where it is necessary to boost the water pressure.

Thanks to the sensors the system automatically switches the pump on and off and a allows a constant supply of water at the required pressure.

How does a domestic waterworks work?

Classic home waterworks

The system is composed of a self-priming pump usually placed in a well, a pressure vessel and a pressure or flow switch. 

When the water outlet is turned on, the pressure drops is detected by the switching unit and the pump starts. The pump always runs at full capacity and the pressure vessel compensates for pressure shocks so that the water pressure in the pipes is constant and at the same time the number of starts is reduced.

When the water outlet is turned off again, the pump runs until the pressure in the tank reaches the desired value again. In practice, pumping by thirds of the volume of the pressure vessel is usually used. By default the pressure vessel is filled by two thirds and the pump is switched off. After opening the tap, water starts to flow, but the pump does not start again until the switching unit detects a drop below one third of the volume. The pump runs until the volume is refilled to two thirds afterwards.

Domestic waterworks with frequency converter

Another option is a domestic waterworks fitted with a pump with a frequency converter, which maintains a constant pressure and suffices with a small pressure vessel. One of the example is the modern Grundfos SCALA2 waterworks. There is an integrated pressure sensor that tells the pump when the flow is started and then compares the pressure measured with the set pressure. Accordingly, it sends a signal to the frequency converter, which immediately sets the pump speed for the desired water pressure.

Thanks to the intelligent control, the system is able to react without delay to situations where the second consumption is started (for example, in addition to the tap, the shower is switched on), without unpleasant fluctuations in the flow when opening or closing another tap. Thanks to the advanced design and control, the pump is also significantly quieter than a conventional domestic waterworks.

How to choose domestic waterworks?

First you need to take into account that the suction head of the self-priming pump cannot exceed 8 meters of pressure loss due to the laws of physics.

Another characteristics:

• Pressure tank volume: usually from 20 liters. Choosing the right volume can prevent the pump from switching too often.
• Pump head,
• Pump flow,
• Pressure vessel material: you will find domestic waterworks with steel and stainless steel tank. Stainless steel is especially suitable if the waterworks will be placed outdoors
• Pressure vessel type - bladder / diaphragm. As the name suggests, there is a bladder inside a tank where water is filled. The main advantage is that there is no contact of water with the tank. Only external moisture has an effect on the corrosion of the vessel. Containers are always treated with anti-corrosion paint. 

What kind of pipe is suitable for domestic waterworks?

We recommend the same pipes as the one used for the rest of the distribution within the building - currently PPR (polypropylene) is usually used for the connection. Special attention must be paid only to the material used for the suction hose, which must not shrink. With common garden hose, as the waterworks creates a vacuum during suction, the hose deflates and becomes clogged. In most cases, nothing gets damaged, as the waterworks are equipped with dry-running protection, but the water does not flow.

Are domestic waterworks equipped with a filter? Where to place it? 

No, there is no filtration. However, we definitely recommend it. The installation of a filter on the DISCHARGE pipe, ie between the waterworks and the first discharge point in the building, is absolutely essential for the correct functionality. A common mistake is to place the filter on the suction pipe. The intention is to protect the pump, but that's wrong. The pressure drop of the filter creates such resistance that the pump may not be able to suck in water at all.

For water cleaning from larger impurities (such as leaves or stones), we recommend to use suction baskets, which are placed at the end of the suction hose directly into the well. Small impurities pass through the pump without any problems and are removed by the filter behind it.

Where to put domestic waterworks?

We recommend installing the domestic waterworks in the technical room, or outdoors under a shed. Remember that the pump must be protected against frost. Either remove it before the winter, or equip it with a heating cable with a thermostat.

Grundfos SCALA2, which is one of the quietest products on the market, can also be installed directly in your home, for example under a sink. The product produces as much noise as a running dishwasher.

Domestic waterworks on our site