WEH-1-304-T/CE | Wilo
Technical data
Tender text

Compact pressure-maintaining system delivered as unit ready for connection, enabling easy installation and commissioning. System consisting of mechanical and hydraulic components as well as control units: Pump, PPH container, pipework and the corresponding equipment, such as: stop valves, connection pipes, overpressure valve, cartridge filters and non-return valves, venting unit for mechanical seal of the pump, pressure sensors, switchgear for the pump. The connection between pump and container, the pressure side and the system provided by the customer and the electrical power supply must still be made.

Wilo-WEH is used to ensure constant and stable pressure in the system. Upon expansion, the fluid is collected in the container and upon contraction it is returned to fill the system.

For installation in commercial properties (office buildings, hotels, hospitals, shopping centres, schools,...) and heating and air conditioning systems for district heating.


Switchgear/control device

Fully-electronic central control unit

  • Plastic housing with protection class IP 54, with main switch
  • Run signal and fault signal
  • Configurable parameters for setting the pressure
  • With function for filling the pump


The MHIL-series multistage pump provides the currently required volume flow and pressure in order to maintain stable pressure at the required level in the system. It can also be used in hot water heating systems, cooling and cold water cycles as well as in industrial circulation systems.


The container is available in sizes 200 l - 5000 l and is made of polypropylene homopolymer with excellent resistance to corrosion. All required connections are prepared. A solenoid valve for filling the container is attached to the container. Furthermore, a level float switch and a float switch for low-water monitoring is attached to the container. A cover with a handle is attached to the top of the container.


Two pipeworks are installed, one each on the pressure and suction side. An overpressure valve is installed between the pipeworks. If the pressure of the fluid increases due to expansion, the overpressure valve opens to allow the fluid to flow from the system back into the container. A stop valve and a filter cartridge are installed on the suction side. A non-return valve and a stop valve are installed on the pressure side. A pressure sensor is installed for monitoring of the system pressure. If the system pressure falls, the sensor recognises this and starts the pump in order to pump the fluid from the container back into the system, increasing the pressure to its setpoint.

Technical data
Height H
1150 mm
Length L
600 mm
Net weight, approx.
46 kg
Width W
702 mm

Certificate REACH (Documents)

REACH regulation

Edition 2020-08
Page format 209.9 x 297.0 mm
Number of pages 2
PDF (158 KB)

4157256, WEH-1-304-T/CE

DWG (1 MB)

4157256, WEH-1-304-T/CE

STP (2 MB)

4157256, WEH-1-304-T/CE

DWG (44 KB)

4157256, WEH-1-304-T/CE

DWG (34 KB)

4157256, WEH-1-304-T/CE

DWG (40 KB)