Grundfos CMBE Variable Speed Booster Sets 230V
The Grundfos CMBE is a compact variable-speed booster set for constant water pressure in homes and light commercial buildings. Each set combines the pump, frequency converter, pressure sensor, 2-litre tank and non-return valve in one unit, runs on a single-phase 230 V supply and is WRAS approved for drinking water.
CMBE model selector
| Model | Part no. | Rated duty point | Max. pressure | Max. flow | Power P2 | Connections |
|---|---|---|---|---|---|---|
| CMBE 1-44 | 98374679 | 40 l/min at 2.8 bar | 4.7 bar | 55 l/min | 0.55 kW | Rp 1" |
| CMBE 3-62 | 98374693 | 70 l/min at 4.4 bar | 6.5 bar | 94 l/min | 1.1 kW | Rp 1" |
| CMBE 3-93 | 98374694 | 70 l/min at 6.5 bar | 9.8 bar | 92 l/min | 1.5 kW | Rp 1" |
| CMBE 5-62 | 98374696 | 100 l/min at 4.7 bar | 6.6 bar | 129 l/min | 1.5 kW | Rp 1¼" in / Rp 1" out |
| CMBE 10-54 | 98382190 | 205 l/min at 2.5 bar | 5.4 bar | 264 l/min | 1.5 kW | Rp 1½" |
Pressure (bar) at each flow
| Flow | CMBE 1-44 | CMBE 3-62 | CMBE 3-93 | CMBE 5-62 | CMBE 10-54 |
|---|---|---|---|---|---|
| 10 l/min | 4.4 | 6.3 | 9.7 | 6.6 | 5.4 |
| 20 l/min | 4.0 | 6.1 | 9.5 | 6.4 | 5.4 |
| 30 l/min | 3.5 | 5.9 | 9.1 | 6.4 | 5.4 |
| 40 l/min | 2.8 | 5.6 | 8.7 | 6.3 | 5.3 |
| 50 l/min | 2.1 | 5.3 | 8.3 | 6.2 | 5.0 |
| 60 l/min | – | 4.9 | 7.4 | 6.1 | 4.8 |
| 80 l/min | – | 3.9 | 5.5 | 5.7 | 4.4 |
| 100 l/min | – | – | – | 4.7 | 4.0 |
| 120 l/min | – | – | – | 3.7 | 3.7 |
| 150 l/min | – | – | – | – | 3.2 |
| 200 l/min | – | – | – | – | 2.5 |
| 250 l/min | – | – | – | – | 1.9 |
Approximate pressure the pump adds at full speed, read from each model's Grundfos pump curve. – means the flow is outside that model's range. Any pressure already at the pump inlet adds to these figures.
How to choose
- Work out the flow you need: count the taps, showers and appliances likely to run at the same time.
- Work out the pressure you need at the highest or furthest outlet, plus pipe losses.
- Find the row for your flow in the table above and pick a model that gives at least that pressure; the speed control turns it down for smaller demands.
- Boosting straight from the mains supply pipe needs notice to your water supplier; a break tank avoids this.
6 products
The Grundfos CMBE 1-44 (part no. 98374679) is a compact variable-speed booster set that keeps constant water pressure in homes and light commercial buildings. Pump,…
The Grundfos CMBE 3-62 (part no. 98374693) is a compact variable-speed booster set that keeps constant water pressure in homes and light commercial buildings. Pump,…
The Grundfos CMBE 3-62 (part no. 98374693) is a compact variable-speed booster set that keeps constant water pressure in homes and light commercial buildings. Pump,…
The Grundfos CMBE 3-93 (part no. 98374694) is a compact variable-speed booster set that keeps constant water pressure in homes and light commercial buildings. Pump,…
The Grundfos CMBE 5-62 (part no. 98374696) is a compact variable-speed booster set that keeps constant water pressure in homes and light commercial buildings. Pump,…
The Grundfos CMBE 10-54 (part no. 98382190) is a compact variable-speed booster set that keeps constant water pressure in homes and light commercial buildings. Pump,…
Frequently Asked Questions
Quick answers to common questions about the Grundfos CMBE Variable Speed Booster Sets 230V. For technical specifications, see the product details above; for sizing or installation advice, contact our team. If you have any other questions, we're happy to help.
What is a water booster pump?
A water booster pump increases the pressure of an existing water supply to give stronger flow at taps, showers and appliances. It can be a small inline pump fitted to the incoming mains, or a larger pump and tank set that draws from a break tank to feed the whole house. Boosters do not create water – they raise the pressure of the water already coming in.
What is the difference between an inline booster and a tank-and-pump booster?
An inline booster connects straight onto the incoming mains and is limited to 12 litres per minute under UK water regulations – examples include the Salamander HomeBoost and WaterBoost WB-Compact. A tank-and-pump booster, such as the Grundfos Home Booster or DAB Esybox with Esytank, draws from a break tank and can deliver much higher flow rates for larger homes with multiple bathrooms.
What is a variable speed booster pump?
A variable speed booster uses an inverter to adjust pump speed in real time to match demand. It maintains constant pressure as outlets open and close, runs more quietly than a fixed-speed pump and typically saves up to 50 per cent of the energy a fixed-speed equivalent would use. The DAB Esybox, DAB Esybox Mini 3 and Grundfos Scala2 are common variable speed examples.
What does a water booster pump do?
A water booster pump raises water pressure to help supply taps, showers and other outlets when the existing system cannot meet demand.
Can a booster pump connect directly to the water mains?
Not every booster can. Direct connection depends on the product design and applicable water regulations; some systems require a break tank.
How do I size a water booster pump?
Assess simultaneous flow demand, required outlet pressure, available inlet conditions and the pressure losses in the pipework.
What types of Grundfos pumps are available?
Grundfos offers circulators, booster pumps, borehole pumps, drainage pumps and other solutions for domestic and commercial systems.
How do I identify the correct Grundfos pump model?
Use the model name and product number on the pump nameplate, then check the electrical, hydraulic and connection specifications.
Can a Grundfos pump improve household water pressure?
A suitably selected Grundfos booster system can improve water pressure or flow, subject to the property’s water supply and installation requirements.