Grundfos MQ 3-45

Stainless steel automatic pump, highest quality, for one to three water points.
In stock
Regular Price £599.00 Discount Price £559.00
  • Delivery in +/- 4 weeks
  • 2 year warranty
Specifications overview
  • Max. pump capacity 4,100 l/h
  • Max. delivery head 44 m / Pressure 4.4 bar
  • Number of sprinklers / water points used at the same time: 4
More specifications »
Grundfos MQ 3-45 Grundfos MQ 3-45
Specifications overview
  • Max. pump capacity 4,100 l/h
  • Max. delivery head 44 m / Pressure 4.4 bar
  • Number of sprinklers / water points used at the same time: 4
More specifications »
Pros and cons
  • Absolute top quality
  • Can run continuously
  • Quiet
  • Dry-running protection
  • Integrated pump control
  • Space-saving design
  • Resistant to limescale and rust
  • High operational reliability
  • Small water-storage tank
Product description

The Grundfos MQ booster pump is a compact water-supply system, designed for domestic, agricultural, and horticultural purposes. This very compact system consists of a pump, motor, pressure valve, and regulator, all of which are combined within an integrated unit. This self-priming pressure-boosting model is equipped with a non-return valve on its suction side, and has built-in protection to prevent the motor from overloading and overheating.  Furthermore, the pump is also protected from running dry. Because of its extremely quiet operation (54DB), this pump can easily be set up within the house.

The Grundfos MQ is available in two models:

  • Grundfos MQ3-35
  • Grundfos MQ3-45

Suitable for drinking water

Opting for the Grundfos pressure-booster pump is an excellent choice because this pump is suitable for drinking water and is multifunctional. It can be used as a pressure-booster pump with storage tanks (maximum 3-bar inlet pressure), and, for example, for supplying water from sources (maximum 8-metre suction height).  The pump is easy to install and to set up. The adjustable angle of the delivery connection allows for easy connecting. The easy control panel has a start/stop button as well as indicator lights to show its status. Please note that this is a self-priming booster, so it may also pump air.

Protection system

An ideal thing about this pump is its auto-restart facility. If the pump is at risk of running dry or experiences a similar failure, it will stop automatically. The pump will then try to restart every 30 minutes over a 24-hour period. With its innovative, built-in leak-detection facility, the pump will warn you in the event of a leakage. The built-in pressure vessel will reduce the number of times the pump switches on and off, thereby preventing unnecessary wear and tear.


The MQ pump is designed for supplying water and increasing pressure, and suitable to use:

  • in homes
  • in holiday cottages and weekend accommodations
  • at farms
  • in vegetable and other large gardens.

This pump is suitable for pumping drinking water and rainwater.

Features and advantages

  • All-in-one pressure-boosting unit
  • Easy to install
  • Easy to operate
  • Self-priming
  • Dry-running protection
  • Quiet
  • Maintenance-free


  • Provides sufficient pressure and capacity for about four sprinklers
  • The hose that can be used for this pump has a diameter of 1" for the delivery connection and 1" for the suction connection
  • Draws water from a maximum depth of 8 metres
  • The maximum delivery head is 44 metres, which equals 4.4 bar output

Contents of the kit

  • Grundfos MQ 3-45 Booster Pump
  • Manual
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Recommended combinations

Flow-rate table
    • 44 metres
    • 40 metres
    • 750 l/h
    • 35 metres
    • 1,550 l/h
    • 30 metres
    • 2,200 l/h
    • 25 metres
    • 2,750 l/h
    • 20 metres
    • 3,300 l/h
    • 15 metres
    • 3,800 l/h
    • 10 metres
    • 4,100 l/h
    • 5 metres
    • 4,100 l/h
    • 0 metres
    • 4,100 l/h


This pump is labelled as being 'quiet'. Of course, like any electric appliance, a pump can be heard, but special attention has been given to its noise level. Thanks to its ultra-low noise level, the pump is highly suitable to be placed indoors, without being disturbing. The perception of noise is subjective, of course, but no other pumps are quieter than these.

Stainless steel / Inox

In some situations, stainless steel, which is also called Inox steel, can be very handy, and is prescribed in particular with regard to drinking water. Drinking water must remain pure and may not contain corrosive elements, which is the reason that stainless steel is used. Furthermore, a stainless steel pump is also resistant to lime, which tends to stick to surfaces, but is not able to do so with smooth, stainless steel surfaces. Cast iron is usually the counterpart of stainless steel, but these pumps are prone to corroding and are therefore used mainly for irrigation. A final advantage of stainless steel is that it is lighter than cast iron and is therefore easier to move.


Grundfos is one of the largest pump manufacturers in the world. They have managed to obtain a substantial share in the industrial market, and have achieved this by supplying the highest quality products over a period of several decades. As a result, Grundfos pumps are currently used in many installations and situations. Not surprisingly, your central heating system may also be fitted with a Grundfos circulation pump. Grundfos was originally a Danish company but it is now represented in many countries all over the world. In addition to manufacturing central heating pumps and targeting the industrial market, Grundfos also sells several garden and booster pumps, and has a line of very robust, high-quality submersible pumps.

Dry-running protection

The name says it all: this pump is protected from running dry. Most pumps cannot, if at all, operate dry for long, which usually ends in the pump immediately burning out and/or seizing. For example, this could happen if the source has run dry and the pump can no longer draw water from it. Garden and booster pumps are particularly sensitive to running dry. Some borehole pumps and somewhat more advanced garden pumps are already equipped with built-in dry-running protection. Others can be easily fitted with a dry-running protection system: for example, with a separate one or with the DAB Control-D. This definitely guarantees that the garden or booster pump will not run dry.

Automatic activation / deactivation

This pump switches on or off automatically if you open or close a water point that is connected to the pump. In many cases, this feature is a considerable advantage: for example, when irrigating a garden with a hand-held sprayer, or supplying a toilet or washing machine with rainwater. It is also useful if you want to increase the water pressure in your home. Unlike standard garden water pumps, water pressure pumps - because of the difference in pressure - 'notice' when one or more water points are opened or closed. This is how the pump knows that it needs to start or stop. Standard water pressure pumps (which are mounted to a tank) are equipped with a mechanical switch, and the more advanced ones have electronic switches. Both systems have advantages and disadvantages. The mechanical switch is reliable but can either not be set or it is difficult to do so, while the electronic version can be set but is dependent on electricity.

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General information

Product package - Grundfos MQ 3-45 Booster Pump
- Cable connection 2 m
- Manual
Warranty 2 year warranty
SKU 5700396723532

Physical specifications

Suction diameter 1"
Delivery diameter 1"
Material Technopolymer and stainless steel
Weight 13,3 kg
Dimensions (l x w x h) 57 x 21,8 x 32 cm

Technical information

Power consumption 1.000 Watt
Max. temperature of liquid 0°C - 35°C
Cable length 2 m


Pump type Booster pump
Applications Garden irrigation, Increase water pressure in the house / apartment, Rainwater use within / around the house, Water supply for cattle
Max. pump capacity 4,100 l/h
Max. delivery head 44 m / Pressure 4.4 bar
Max. suction depth 8 m
Suitable for prolonged use (> 3 hours) Yes
Automatic on/off switch Yes
Dry run protection Yes
Inverter No
Filter No

Types of water this pump is able to process

Clean water Yes
Rainwater Yes - in the presence of sand/grit i.c.w. 5' Filter for solids
Groundwater Yes - in the presence of sand/grit i.c.w. 5' Filter for solids
Slightly dirty water Yes - i.c.w. 5' Filter for solids
Canal water Yes - i.c.w. 5' Filter for solids
Lake water Yes - i.c.w. 5' Filter for solids
River water Yes - i.c.w. 5' Filter for solids
Ditchwater Yes - i.c.w. 5' Filter for solids
Pond water Yes - i.c.w. 5' Filter for solids
Muddy water No
Salt water No
Faecal matter / manure pit No
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    Regular Price £599.00 Discount Price £559.00
    4,100 l/h
    44 m / Pressure 4.4 bar
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