Grundfos Home Booster 4.5

Questions and Answers

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Rebecca WalkerAug 8, 2025
What to do if Grundfos Home Booster 4.5 light is on but pump doesn't run?
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  Darrell GoodwinAug 8, 2025
  If the 'Pump On' light is illuminated on the PM2 of your Grundfos Water Pump, but the pump isn't running, it could be due to a defective relay contact in the PM2 or a seized pump shaft. Check the electrical supply in the pump motor terminal box. If there's no voltage between Live and Neutral terminals, the PM2 is faulty. Also, check that the pump shaft is free to rotate.
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mccluretroyAug 13, 2025
What to do if Grundfos Home Booster 4.5 runs then stops and red light is on?
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  Bianca HamiltonAug 13, 2025
  If your Grundfos Water Pump runs briefly, then stops and a red light comes on, here's what you can check: * The pump may be air locked, so check that the pump is vented. * The storage tank might be empty, so check the water level in the storage tank. * Also check the incoming mains water supply and the ball valve for any debris.
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Kristen HopkinsAug 19, 2025
How to troubleshoot no lights on Grundfos Water Pump PM2 controller?
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  Bryan YoungAug 19, 2025
  If there are no lights on the PM2 controller of your Grundfos Water Pump, it indicates a power supply issue. First, check that the mains isolator is ON. Next, check the fuse in the plug or switched fuse isolator. Finally, confirm that there is 240V between Live and Neutral.
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Adam MillerAug 26, 2025
Why Grundfos Home Booster 4.5 delivers pressure but doesn't stop?
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  tiffanyhallAug 26, 2025
  If your Grundfos Water Pump delivers the correct pressure but doesn't stop when there's no demand, it could be due to a couple of reasons. First, the pressure setting might be too high, so check the switch settings in the PM2 controller. Second, there might be a flow demand or a leak in the system. To check this, close the outlet isolating valve; the pump should stop. If it does, a system flow is keeping the pump running on the flow switch.
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jenniferjamesAug 31, 2025
Why Grundfos Water Pump stops and starts again?
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  Amanda RodriguezAug 31, 2025
  If your Grundfos Water Pump stops and then restarts after a few seconds, the precharge pressure in the vessel might be incorrect. Check the vessel precharge pressure and adjust it to 90% of the cut-in pressure setting.

Summary

Declaration of Conformity

General Data

Details about delivery, handling, inspection, warranty, site storage, applications, and operating conditions.

MAXIMUM OPERATING CONDITIONS

Specifies liquid temperature, ambient temperature, humidity, maximum pressures, and noise level.

WRAS APPROVAL

Confirmation of WRAS approval for wetted components for potable water use.

Quick Guide

INSTALLATION

Steps for installing the Home Booster, including foundation, water supply, overflow, discharge, and electrical connections.

COMMISSIONING

Procedure for venting the pump to ensure proper operation and pressure generation.

TESTING

Steps to test the pump operation and pressure build-up after installation and commissioning.

Installation

GENERAL INFORMATION

Key advice on discharge pipework size, support, local regulations, and electrical installation.

WATER QUALITY

Guidance on maintaining water quality, preventing bacterial growth, and periodic cleaning.

LOCATION

Recommendations for siting the Home Booster in a dry, ventilated, frost-free position, avoiding roof spaces.

FOUNDATION & MOUNTING

Requirements for mounting the Home Booster on a solid, flat, and level foundation, preferably concrete.

STORAGE TANK

Information on the integral storage tank, water quality, and capacity considerations.

SLAVE TANK

BYPASS

WEIGHTS & DIMENSIONS

Electrical General

Electrical Connections

ELECTRICAL SUPPLY CONNECTION

Guidance on connecting the Home Booster's mains cable via plug or permanent wiring.

Commissioning

DISCHARGE PRESSURE SETTING

PM2 CONTROLLER SETTING

VESSEL PRE-CHARGE PRESSURE

Operation

FROST PROTECTION

Maintenance

INSPECTION

Checks to perform during shutdown, including leaks, corrosion, shaft rotation, and precharge pressure.

Fault Finding Chart

SPARES PARTS

Grundfos Home Booster 4.5 Specifications

General

Model	Home Booster 4.5
Max Flow Rate	4.5 m³/h
Max Head	45 m
Pump Housing	Stainless steel
Impeller	Composite
Frequency	50 Hz
Motor Phase	1
Housing Material	Stainless steel
Power Supply	230V, 50Hz
Pump Type	Centrifugal
System Pressure	10 bar
Approvals	CE