Grundfos MQ3-45 Mark III Pump

Sku: 240-MQ3-45-BASE

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Regular Price: $1,095.00
Sale Price: $657.20
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The Grundfos' MQ pump is compact and extremely easy to install. The pressure switch and tank are already built into the MQ. Furthermore, it is self-priming and water-cooled with a very low noise level.

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Product Description

Product Description

Grundfos MQ3-45 1 HP Pressure Booster Pump:

The Grundfos' MQ pump is compact and extremely easy to install. The pressure switch and tank are already built into the MQ. Furthermore, it is selfpriming and water-cooled with a very low noise level. The outlet pipe connection can be angled up to 5° to fit your existing pipe-work. The Grundfos' MQ pump is simple and easy to operate. The settings are clearly indicated on the user-friendly control panel with indicator lights for Pump on/off, auto reset, and an alarm indicating dry running or overheating. Grundfos MQ is built for trouble-free operation. It's construction from corrosion-resistant materials means it can be used for ultrapure water. The anti-cycling feature prevents the pump from repeatedly starting and stopping in the event of a dripping tap or a minor leak. If there is no water available, the pump will stop to protect itself and restart automatically when water is available again.  The Grundfos MQ makes it easy to select the right water booster pump. The MQ is an all-in-one unit with two models to choose from.  There is no need to worry about a separate pressure tank, pressure switch, electrical connections, fittings or any other separate items. With MQ, it is literally a matter of connecting the power and turning on the jet pump. Installation of an MQ pump is simple and can be done in a matter of minutes.


  • The MQ pump has built-in dry-run protection. If the pump runs dry, the pump automatically stops.
  • It will then attempt to restart every half hour for a maximum of 24 hours until water is available from the source.
  • If more than 24 hours pass without water, the pump must be restarted manually.
  • The auto reset function can also be disabled.
  • The Grundfos MQ pump also has built-in thermal protection.
  • If the pump overheats it immediately stops.
  • After a 30-minute cooling-down period, the pump will automatically restart


  • The Grundfos MQ is specially designed for use in domestic applications where low noise is a major consideration.
  • The pump is cooled by the pumped water which eliminated the need for a noisy cooling fan.
  • Since the pump is self-cooling, you don’t need to have free space around the pump for cooling purposes. 
  • The MQ "anti-cycling" feature prevents the pump from continuously starting and stopping when you have a dripping tap or minor leak in the system.


  • Flow range: 0 - 20 U.S. GPM
  • Head range: 0 - 139 FEET
  • System pressure: Up to 109 psi
  • Voltage Range:  110-120V or 220-240V
  • Inlet pressure: Max. 45 psi
  • Suction lift: Max. 26 ft
  • Liquid temperature: 32°F to +95°F
  • Ambient temperature: 32°F to +113°F
  • Inlet and outlet connections: 1" IPS
  • Warranty:  2 Years

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Additional Information

Additional Information

Availability In Stock
Manufacturer Grundfos

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Ratings & Reviews

Ratings & Reviews

  • 5/1/2013

    good so far

    By on

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Product FAQs

Product FAQs

  • Can I use an external pressure switch? As in on the pipe going from the discharge (top) to an external bladder tank for keeping pressure to the house. Where can the wires plugin for this external pressure sensor to start/stop the pump as needed?

    This particular pump does not operate the way you are describing.  It does not have output connections.  This pump is designed to keep constant pressure at the rated flow rate.  It will come on around 40-45 PSI and shut down at around 60-65 PSI.  This is a variable speed pump that will ramp up as demand increases.  It has an internal bladder and pressure switch to control it.  We typically don’t use storage tank with it.  If you want that type of pumping system you would want to buy one of these units;