Grundfos Magna1 65-100F 99221373 340mm Flanged Circulating Pump #3625/4678

GRUNDFOS MAGNA1 65-100F 340 – Flanged Circulating Pump (99221373) #3625/4678

This listing is for a Grundfos MAGNA1 wet-rotor circulator pump. MAGNA1 combines the high energy efficiency of a permanent-magnet synchronous motor with an integrated frequency converter, providing reliable variable-speed circulation control for HVAC and hot-water systems.

The pump uses a maintenance-free canned-rotor design with integrated electronics. Setup and monitoring can be carried out via the onboard interface or wirelessly using Grundfos GO Remote.

Condition: supplied as surplus / unused stock. The unit may show cosmetic marks consistent with storage and handling. It is inspected prior to dispatch.
Guarantee: supplied with our 2-year guarantee.

• Pump type: MAGNA1 single-head wet-rotor circulator
• Connection: DN65 flanged (PN6/10)
• Port-to-port length: 340 mm
• Electrical supply: 1 × 230–240 V, 50 / 60 Hz
• Motor: permanent-magnet synchronous (PM)
• Control: integrated frequency converter with user interface
• Communication: Grundfos GO Remote compatible

Need help confirming suitability?
Call us on 01803 220416 for technical advice.

Manufacturer product page

Full technical specifications and performance curves can be viewed on the official Grundfos product page:
View Grundfos MAGNA1 65-100F (99221373) – Variant details

Frequently Asked Questions

What does the model number mean?

• MAGNA1 – high-efficiency variable-speed wet-rotor circulator range
• 65 – nominal connection size (DN65)
• 100 – hydraulic performance series / head class
• F – flanged connection version
• 340 – port-to-port installation length in millimetres

Why choose a MAGNA1 instead of a MAGNA3?

The MAGNA1 is ideal for users who need an efficient circulator without complex BMS features. Compared with MAGNA3:

• MAGNA1 offers simpler setup and operation with lower cost
• Ideal where only basic control modes are required
• Still provides substantial energy savings via PM motor and integrated drive
• Includes fault relay and digital start/stop input

Choose MAGNA3 when you need advanced flow/energy monitoring, full building management communication (BACnet/LON), or multi-pump cascade control. For straightforward HVAC circulation where simplicity and efficiency are the priority, MAGNA1 is usually the better value choice.

Is the pump maintenance-free?

Yes. The wet-rotor canned design has no mechanical shaft seal, resulting in very low maintenance and quiet operation.

Can this replace older fixed-speed pumps?

Yes — subject to hydraulic and connection match. The variable-speed electronics in a MAGNA1 can deliver significant energy savings compared with traditional fixed-speed circulators, but system duty and connection type should be confirmed before replacement.

About Our Stock

Stock code: #3625/4678
We specialise in supplying quality pumps and equipment. This unit is supplied as surplus stock, inspected prior to dispatch and supplied with a 2-year guarantee.