Grundfos CMB3-46PM1 Water Pressure Booster Pump 0.5kW

The Grundfos CMB3-46PM1 is a compact water pressure booster pump designed to improve water pressure in homes. Its built-in PM1 pressure control helps deliver stronger pressure to showers, taps and everyday household water use. It comes with a 0.5 kW motor and a 2 m power cable with plug for convenient electrical connection.

Key Features & Benefits

• Built-In Pressure Control: Built-in PM1 pressure control helps provide strong, constant water pressure around the house.
• Improved Household Water Pressure: Helps boost water pressure for showers, taps and household water needs, making everyday use more comfortable.
• Dry-Running Protection: The CMB PM1 Booster includes dry-running protection.
• Motor Overload Protection: Built-in motor protection responds to excessive current and temperature, helping protect the motor against overload.
• Durable Construction: Features a sturdy cast-iron pump housing with corrosion-resistant stainless steel impellers and shaft for dependable operation.
• Quiet & Compact Design: Combines quiet operation with a space-saving design, making it suitable for residential installations.
• Maintenance-Free Design: Designed to minimise routine upkeep, making the pump convenient for everyday household use.
• Convenient Connections: Equipped with a 1-inch female inlet, 1-inch male outlet and a 2 m power cable with plug for straightforward connection during installation.

What Does PM1 Mean?

PM1 refers to the built-in pressure control of the CMB PM1 Booster. Unlike the CMB PT series, the PM1 version does not require a separate pressure tank, giving it a more compact design.

The CMB PT series uses a pressure tank and pressure switch to reduce frequent pump starts and provide smoother water delivery, making it an alternative for homeowners who prefer a pressure-tank system.

Technical Specifications

• Model: Grundfos CMB3-46PM1 (CMB 3-46 PM1)
• Pump type: Horizontal multistage centrifugal booster with PM1 pressure control
• Grundfos product code: 93332810
• Motor power (P2): 0.50 kW (0.67 HP)
• Maximum current: 3.30 A (at 220–230 V)
• Power cable: 2 m with plug
• Maximum flow: About 68 L/min (approx. 4.1 m³/h, read from the pump curve)
• Maximum head: About 46 m at zero flow (read from the pump curve)
• Maximum system pressure: 10 bar
• Inlet connection: Rp 1 (1-inch female)
• Outlet connection: G 1 (1-inch male)
• Pump housing: Cast iron
• Impellers: Stainless steel (AISI 304)
• Pump shaft: Stainless steel (AISI 304)
• Diffusers: Technopolymer
• Shaft seal: Carbon with resin / ceramic
• Enclosure rating: IP55; undercover installation recommended
• Insulation class: F
• Length: 342 mm
• Mounting-base width: 158 mm
• Height: 315 mm
• Weight: 14 kg
• Sound pressure level: Below 55 dB(A) (may be higher during priming)
• Pumped liquid: Clean water

Where It Works Best

The Grundfos CMB3-46PM1 is ideal for improving water pressure in homes supplied by a suitable water storage tank. Whether you're dealing with weak shower pressure or slow-running taps, it helps make everyday water use more comfortable.

• Residential Homes: Suitable for houses, villas and multi-storey homes that need improved water pressure for showers, taps and household water supply.
• Instant Water Heater Showers: Suitable for boosting water pressure to showers using instant electric water heaters, subject to the heater's operating requirements.
• Garden Use: Helps improve water pressure at garden taps for everyday watering needs.
• Light Commercial Applications: Can also serve small offices, guesthouses and similar premises with modest water demand.

How Many Bathrooms Can It Support?

The recommended bathroom count depends on your home's water supply, plumbing layout, shower type and the number of outlets used simultaneously.

For homes with rain showers or higher water demand, check the appropriate pump size before purchasing.

Water Supply & Installation Requirements

The CMB3-46PM1 is designed for installations with positive inlet pressure, such as water supplied from an elevated storage tank or a ground-level tank where the water level is above the pump.

This is not a self-priming pump and should not be used to draw water from an underground tank or well where suction lift is required.

Install the pump in a sheltered, well-ventilated location on a firm, level surface. The pump must be properly primed before operation, and plumbing and electrical connections must follow Grundfos installation instructions and applicable local requirements.

Need help choosing the right pump? Contact CT Hardware with your water source, number of bathrooms and shower types. Our team can assist with product selection, although installation should be handled by a qualified installer.

Compare & Choose

• Prefer a pressure-tank system? The Grundfos CMB3-46PT features an 18 L pressure tank and pressure switch, offering an alternative to the CMB3-46PM1's built-in PM1 pressure control.
• Explore other Grundfos CMB models: Browse our Grundfos CMB Booster Pumps collection to compare different pump capacities and configurations.
• Need a different type of booster pump? Explore our Grundfos Booster Pumps collection for other options, including variable-speed and self-priming models.
• Not sure which pump suits your home? Our Grundfos Booster Pump Buying Guide helps you compare models based on your bathroom requirements and water supply.

Warranty & Certification

• SIRIM Certified: Grundfos CMB booster pumps are SIRIM certified.
• 2-Year Manufacturer Warranty: Backed by a Grundfos 2-year warranty, subject to applicable terms and conditions. View our Grundfos Warranty Guidelines for coverage and registration details.
• Grundfos DBS Professional Dealer: CT Hardware Sdn Bhd is listed in Grundfos Malaysia's Domestic Building Services (DBS) Professional Dealer directory.