The Grundfos UPM4 primary circulation pump is an externally speed-controlled circulator designed to run as the primary (or sole) pump in Samsung heat pump systems. Speed is taken directly from the Samsung heat pump control board via a PWM signal, allowing the outdoor unit to modulate flow precisely to match heating demand rather than running the pump at a fixed speed.
Available in two power variants — the standard UPM4 (60W, 8m head) and the higher-output UPM4XL (90W, 9m head) — both share the same 130mm port-to-port dimension and 1½" pipe thread connections, and are supplied complete with a power lead and PWM speed control cable. These pumps only operate under external speed control from a Samsung heat pump control board and are not intended for standalone or manually-controlled use.
Please Note
These pumps only operate when taking external speed control from a Samsung heat pump control board via the supplied PWM cable. They are not designed to run as a standalone, fixed-speed or manually-controlled circulator.
Key Features
External PWM Speed Control
Speed is controlled directly by the Samsung heat pump control board via a low-voltage PWM signal, allowing precise flow modulation to match system demand.
Two Power Variants
Available as the standard UPM4 (60W, 8m head) or the higher-output UPM4XL (90W, 9m head) for larger systems and direct circuits.
Supplied Ready to Install
Shipped complete with a power lead and PWM speed control cable, reducing on-site wiring work.
Compact 130mm Footprint
A 130mm port-to-port length with 1½" pipe threads suits straightforward retrofit and new-build plant room installation.
Maintenance-Free Operation
The pump requires no external motor protection and needs no routine servicing under normal operation.
Wide Liquid Temperature Range
Suitable for heating system water meeting recognised water quality standards, supporting reliable long-term operation.
Variant Comparison
Model
Max. Power
Max. Head
Port-to-Port
Pipe Thread
Grundfos UPM4 (25-75 130)
60W
8m (7.5m)
130mm
1½"
Grundfos UPM4XL (25-90 130)
90W
9m
130mm
1½"
Technical Specification
Application
Pump Type
Primary circulation pump, externally speed-controlled
Control Method
Low-voltage PWM signal from Samsung heat pump control board
Typical Use
Primary or sole pump in Samsung heat pump systems
Supplied With
Power lead and PWM speed control cable
Electrical
Supply Voltage
1 x 230V +10% / -15%, 50/60Hz
Motor Protection
Not required – protected internally by control box electronics
Insulation Class
F (EN 60335-1)
Enclosure Class
IP44 (standard, non-drain-hole version)
Mechanical & Installation
Port-to-Port Length
130mm
System Pressure (Cast Iron Housing)
Up to 10 bar (1 MPa)
Storage Temperature
-40°C to +75°C
Pumped Liquid Requirements
Liquid Type
Clean, thin, non-aggressive heating system water
Water Quality Standard
Compliant with accepted heating system water standards (e.g. VDI 2035)
Antifreeze Compatibility
Water/glycol mixtures up to 50% by volume, kinematic viscosity below 10 mm²/s
Frequently Asked Questions
What is the difference between the UPM4 and UPM4XL?▼
The standard UPM4 has a 60W motor and 8m maximum head, while the UPM4XL has a more powerful 90W motor and 9m maximum head, making it better suited to larger Samsung heat pump systems or direct circuits with higher resistance.
Can this pump be run without a Samsung control board?▼
No. Both variants are designed to take external speed control from a Samsung heat pump control board via the supplied PWM cable and are not intended for standalone or manually fixed-speed operation.
What pipe connection size do these pumps use?▼
Both the UPM4 and UPM4XL have a 130mm port-to-port length and use 1½" pipe threads.
Does the pump need external motor protection?▼
No. The motor is protected by the electronics in the control box and requires no external motor protection device.
What is supplied with the pump?▼
Each pump is shipped with a power lead and PWM speed control cable ready for connection to the Samsung control board.
What is the maximum operating pressure?▼
For cast iron and stainless steel pump housings, the maximum system pressure is 10 bar (1 MPa).
