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WEH-1-303-M/CE | Wilo
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Article number: 4157251
Technical data
Technical data
Activation type Direct On Line (DOL)
Number of pumps 1
Connection standard DIN EN 10226-1
Control Without frequency converter
Diaphragm pressure vessel no
Drinking water and water for food-processing companies in accordance with TrinkwV 2001 (drinking water ordinance) no
Phases 1
Electromagnetic compatibility EN 61000
Flow rate Q 4 m³/h
Heating water (as per VDI 2035) yes
Max. inlet pressure 10 bar
Installation Base frame installation
Insulation class F
Mains frequency f 50 Hz
Motor protection PTO
Rated power P2 550 W
No. of poles 2
Number of stages -
Rated speed n 2900 1/min
Rated voltage U 230 V
Voltage tolerance ±10 %
Mains connection 1~230 V, 50 Hz
Dimensions L 600.0 mm
Dimensions H 1150.0 mm
Dimensions H1 395.0 mm
Dimensions P 678.0 mm
Product data
Brand Wilo
Product description WEH-1-303-M/CE
Article number 4157251
EAN number 4048482173856
Colour Green/black/silver
Minimum order quantity 1
Date of sales availability 2015-03-01
Packaging type Special pallet
Packaging property Sales packaging
Pieces per pallet 1
Number per layer 1
Dimension, weight
Length with packaging 800 mm
Length L 600 mm
Height with packaging 1285 mm
Height H 1150 mm
Width with packaging 1200 mm
Width W 678 mm
Gross weight, approx. m 61 kg
Net weight, approx. m 45 kg
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. 45 kg
Width W 678 mm

Installation and operating instructions


Article Number 4255848
Edition 2023-03
Page format 209.9 x 297.0 mm
Number of pages 44
PDF (6 MB)

Wilo-Control CE+ WEH/WEV

Article Number 4163847
Edition 2011-09
Page format 50.4 x 71.3 mm
Number of pages 22
PDF (997 KB)

Certificate REACH

REACH Regulation

Edition 2021-05
Page format 209.9 x 297.0 mm
Number of pages 4
PDF (262 KB)



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