Grundfos CMBE is a complete packaged constant-pressure booster — a stainless-steel CME multistage pump with an integrated variable frequency drive, delivered with the five-way fitting, check valve, diaphragm tank, pressure sensor and gauge already fitted. Ten models serve flows up to about 60 GPM and heads to 325 ft in 115 V and 230 V, and three CMBE TWIN systems put two pumps in parallel with cascade control and automatic pump alternation for apartment buildings, hotels and light industrial plants. The IE5 motor and variable-speed control hold steady pressure while cutting energy use, and every model is certified to NSF/ANSI 61 and 372 for drinking water. Note that CMBE is a flooded-suction system, not self-priming — if you need to lift from a tank or shallow well, ask us about Grundfos SCALA instead. Watermain Supply sells the U.S. 60 Hz range with engineering-led sizing to your fixture count, elevation and inlet pressure. Call 1-888.510.4036 and we will size it for you.
Grundfos MI 301 Bluetooth Mobile Interface for Grundfos GO
Price
$558.93
Grundfos CMBE Booster Systems
Grundfos Pumps
Grundfos CMBE Constant Pressure Booster Systems
Packaged variable-speed boosters built on the stainless CME multistage pump — ten single-pump builds and three twin systems, from a single-family home to an apartment building, hotel or small industrial plant.
10 ModelsSingle-pump range
Up to 70 GPMSingle pump
Up to 365 ftShut-off head
145 psiMax system pressure
NSF 61 / 372Drinking water
Grundfos CMBE is a complete packaged pressure-boosting system, not a bare pump. Each unit pairs a stainless-steel CME horizontal multistage pump and premium-efficiency IE5 motor with an integrated variable frequency drive, and arrives with the five-way fitting, integrated non-return valve, diaphragm tank, outlet pressure sensor and pressure gauge already fitted. A pressure sensor watches demand and the drive varies motor speed to hold a constant pressure in the pipe system — connect the pipes, plug it in, set the pressure on the panel, and it runs.
The range covers ten single-pump builds serving up to 70 GPM and 365 ft of head, plus three CMBE TWIN systems that put two pumps in parallel on a common base with cascade control and automatic alternation, reaching 141 GPM combined. Watermain Supply offers the U.S. 60 Hz range in 115 V and 230 V with engineering-led sizing to your fixture count, elevation and inlet pressure. Compare the models below, or call 1-888.510.4036 and we will size it for you. Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
Control It From Your Phone — Grundfos GO & the MI 301
Every CMBE and CMBE TWIN is radio-enabled for the free Grundfos GO app — but the app cannot talk to the pump on its own. The Grundfos MI 301 is the mobile interface that bridges the two. It is a pocket-sized rechargeable module that pairs to an iOS or Android phone over Bluetooth Low Energy, then reaches the pump by radio — up to 30 m, no line of sight needed — or by infrared. One module covers the whole Grundfos range.
How it is used on a CMBE: power up the module and pair it to Grundfos GO over Bluetooth once, then it reconnects on its own. Radio - List scans every radio-enabled Grundfos product in range with its name, status and signal strength; Radio - Connect goes straight to one pump and IR - Connect points the module at the pump from within a metre. The wink command flashes a light on the selected unit, so you know you are on the right pump in a room with several. From the dashboard: set the pressure set point, read live operating parameters and alarm history, and install firmware updates when Grundfos publishes them.
The MI 301 is not needed to run a CMBE — the set point is entered on the pump's own panel. What it changes is the depth of the visit: commissioning and troubleshooting with data on screen, and no laptop or proprietary service tool. Sold separately, with charger, USB cable and quick guide.
Grundfos GO and GO Remote are free apps from Grundfos Holding A/S. The MI 301 mobile interface is required to connect the app to the pump and is sold separately.
The CMBE Line
Two configurations of the same integrated-VFD system: one pump for domestic and light-commercial supply, or two in parallel with cascade control for larger buildings and standby duty.
CMBE
Single-pump constant pressure
10 Models1, 3, 5 and 10 families
Up to 70 GPMsingle pump
Up to 365 ftshut-off head
115 / 230 V1-phase
A CME multistage pump with integrated frequency converter, five-way valve, diaphragm tank, pressure sensor and gauge in one package. The speed controller holds constant pressure as demand changes, with dry-running, overload and over-temperature protection built in. Stainless AISI 304 hydraulics, IE5 motor with TP 211 thermal protection, 55 dB(A).
Key specifications
Four flow families: to 14.5, 26.4, 35.2 and 70.4 GPM
Max system pressure 145 psi (10 bar)
Cut-in 7.25 psi below set point, 100 starts/hour
Liquid 32–140°F, ambient -4 to 131°F
Flooded suction; max 3.3 ft lift, not self-priming
NSF/ANSI 61 + 372; 230 V models UL listed packaged system
Best forSingle- and two-family houses, cluster homes, blocks of flats, schools, small hotels and offices, agriculture and irrigation supply.
Two complete CMBE pumps in parallel on a common base plate with a manifold set of inlet and outlet pipes, ball valves and unions. Each pump keeps its own VFD, tank, sensor and check valve. Cascade control stages the second pump in as demand rises; alternation starts whichever pump has the fewest running hours.
Best forApartment buildings, cluster homes, hotels, schools, small office buildings, hospitals, small industrial plants, and domestic fire suppression.
All ten U.S. 60 Hz builds. The model number states nominal flow in m³/h and Grundfos’ nominal head in metres — a CMBE 3-62 is a 3 m³/h family pump with a 62 m nominal head designation. That designation is close to, but not the same as, the shut-off pressure the published curve actually shows, so both are listed below. Power figures are maximum P1 input.
Model
Max plotted flow
Nominal head (model no.)
Shut-off on curve
115 V
230 V
Max P1
Product No.
CMBE 1-44
14.5 GPM
44 m / 144 ft
157.8 ft (68.3 psi)
Yes
Yes
0.84 HP
98810910 / 98548109
CMBE 1-75
14.5 GPM
75 m / 246 ft
266.2 ft (115.3 psi)
Yes
Yes
1.34 HP
98810921 / 98548110
CMBE 1-99
14.5 GPM
99 m / 325 ft
365.0 ft (158.0 psi)
—
Yes
1.68 HP
98548111
CMBE 3-30
26.4 GPM
30 m / 98 ft
Not plotted below 14.5 GPM
Yes
Yes
0.92 HP
98810922 / 98548112
CMBE 3-51
26.4 GPM
51 m / 167 ft
170.5 ft (73.8 psi)
Yes
—
1.18 HP
98810924
CMBE 3-62
26.4 GPM
62 m / 203 ft
Not plotted below 11.7 GPM
—
Yes
1.62 HP
98548113
CMBE 3-93
26.4 GPM
93 m / 305 ft
Not plotted below 4.6 GPM
—
Yes
2.31 HP
98548114
CMBE 5-31
35.2 GPM
31 m / 102 ft
Not plotted below 26.4 GPM
—
Yes
1.46 HP
98548115
CMBE 5-62
35.2 GPM
62 m / 203 ft
Not plotted below 20.3 GPM
—
Yes
2.31 HP
98548116
CMBE 10-54
70.4 GPM
54 m / 177 ft
182.8 ft (79.2 psi)
—
Yes
2.29 HP
98548118
Connections are 1 in NPT except the CMBE 5 outlet (1-1/4 in NPT) and the 10-54 (1-1/2 in NPT both ports). Grundfos plots the range on one family chart and does not draw every build to zero flow; where the low-flow end is not drawn, this table says so rather than extrapolating it. Source: Grundfos CMBE & CMBE TWIN Data Booklet 98647967 (10.2025), charts TM090716 and TM090949.
Pressure Added Across the Flow Range
Every figure is the pressure the unit adds on top of whatever arrives at its inlet — never the discharge pressure and never the set point. Zero flow is a ceiling, not a working point. Pick the flow family first, then the build that covers the boost you need.
CMBE 1 — to 14.5 GPM
Flow — GPM
0
2
4
6
8
10
12
14
CMBE 1-44 — psi
68.3
65.7
61.8
56.6
50.3
43.0
34.9
26.5
CMBE 1-44 — ft
157.8
151.8
142.7
130.8
116.2
99.3
80.7
61.3
CMBE 1-75 — psi
115.3
111.0
104.5
95.9
85.4
73.4
60.1
45.7
CMBE 1-75 — ft
266.2
256.4
241.3
221.4
197.2
169.6
138.9
105.5
CMBE 1-99 — psi
158.0
152.3
142.0
130.3
111.3
93.7
77.1
59.5
CMBE 1-99 — ft
365.0
351.7
327.9
301.0
257.0
216.5
178.0
137.3
CMBE 3 — to 26.4 GPM
Flow — GPM
12
14
16
18
20
22
24
26
CMBE 3-30 — psi
—
—
36.7
34.3
31.5
28.3
24.7
20.5
CMBE 3-30 — ft
—
—
84.7
79.1
72.7
65.4
57.1
47.4
CMBE 3-51 — psi
62.0
54.6
48.0
42.2
36.9
32.0
27.3
22.7
CMBE 3-51 — ft
143.2
126.1
110.9
97.5
85.3
73.9
63.0
52.5
CMBE 3-62 — psi
78.9
75.1
70.8
65.8
60.1
53.4
45.8
37.0
CMBE 3-62 — ft
182.2
173.5
163.5
152.0
138.7
123.4
105.7
85.4
CMBE 3-93 — psi
123.2
117.2
107.1
96.7
86.2
75.8
65.5
55.6
CMBE 3-93 — ft
284.5
270.6
247.4
223.4
199.1
175.0
151.3
128.3
Shut-off at zero flow: CMBE 3-51, 73.8 psi (170.5 ft). The 3-30, 3-62 and 3-93 curves are not drawn below 14.5, 11.7 and 4.6 GPM; at those lowest plotted points they read 38.4, 79.3 and 138.7 psi.
CMBE 5 — to 35.2 GPM
Flow — GPM
22
24
26
28
30
32
34
CMBE 5-31 — psi
—
—
—
36.2
34.2
32.1
29.7
CMBE 5-31 — ft
—
—
—
83.5
79.0
74.2
68.6
CMBE 5-62 — psi
80.1
74.8
69.4
64.0
58.7
53.5
48.4
CMBE 5-62 — ft
185.0
172.7
160.3
147.9
135.6
123.5
111.8
Neither CMBE 5 curve is drawn to zero flow. The 5-31 begins at 26.4 GPM and 37.5 psi; the 5-62 begins at 20.3 GPM and 84.5 psi.
CMBE 10-54 — to 70.4 GPM
Flow — GPM
0
10
20
30
40
50
60
70
CMBE 10-54 — psi
79.2
76.4
64.3
54.3
46.0
38.7
31.9
25.1
CMBE 10-54 — ft
182.8
176.5
148.6
125.5
106.2
89.3
73.6
57.9
Fed by a city main — which is what CMBE is built for, since it wants a flooded suction. The drive holds the pressure you set and only makes up the difference between the main and your setting, so on a stronger main the same unit reaches that setting at a higher flow. Incoming pressure buys you more flow, not more pressure. Boost in psi equals head in feet multiplied by 0.433.
Figures are at full drive speed; the drive holds lower pressures by running slower. Grundfos publishes CMBE performance only as a plotted family chart with no duty table, so these figures are read from the published curve and rounded down where uncertain. Nothing is extrapolated or transposed. The 3-51 and 10-54 rows come from the single-pump axis of chart TM090949, which draws those two curves in full. Source: data booklet 98647967 (10.2025), pages 17 and 21, ISO 9906:2012 3B.
CMBE TWIN: Cascade Control & Alternation
What the twin system adds over a single pump, and why it matters in a building.
Cascade control
The system adapts to consumption by switching pumps on or off and varying the speed of those running, so it holds constant pressure using only the number of pumps the demand actually requires.
Automatic alternation
Running hours are distributed evenly. The system starts whichever pump has accumulated the fewest running hours since power was last switched off, so neither unit wears out ahead of the other.
Standby redundancy
Two independent pumps, each with its own drive, tank, sensor and check valve, on a shared manifold. If one is down, the building still has water — the reason CMBE TWIN suits hospitals and hotels.
Higher peak flow
Both pumps run together when demand calls for more than one can deliver at the set pressure. Grundfos plots the two-pump case on its own axis: 28.9 GPM combined on the TWIN 1-44, 52.8 GPM on the 3-51 and 140.9 GPM on the 10-54.
Two pumps hold more pressure at the same flow
Each pump in a twin carries half the water, so each sits higher on its own curve — and Grundfos publishes both cases on one chart rather than leaving it derived. Read down a column instead of across a row and the pressure gain appears.
System
Flow drawn
One pump adds
Two pumps add
Shut-off (unchanged)
CMBE TWIN 1-44
14 GPM
26.4 psi
53.4 psi
68.2 psi
CMBE TWIN 3-51
24 GPM
27.3 psi
62.0 psi
73.8 psi
CMBE TWIN 10-54
60 GPM
31.9 psi
54.4 psi
79.2 psi
The shut-off ceiling at zero flow is the one figure that does not rise, because it is fixed by the pump build. Figures read from the two-pump and one-pump axes of Grundfos chart TM090949 (98647967, 10.2025).
Two rules for a twin. Size so one pump can carry the building — on a duplex bought for redundancy, the design flow should sit inside what a single pump delivers, or losing a pump means losing pressure. And plan for an electrician: single CMBE units ship with a 4.9 ft cable and a US plug, while CMBE TWIN is intended for fuse-box connection with a 15 ft cable and no plug.
How we size a CMBE, and the one limit that catches people out.
Run the numbers yourself
Two calculators do the arithmetic below. The booster sizing calculator turns fixture count, floors and inlet pressure into the flow and boost you need, then checks a chosen pump against them. The CMBE ships with its own diaphragm tank, but a break or storage tank ahead of the pump, and the thermal expansion tank at any storage water heater, still have to be sized.
Required boost equals the pressure you want at the highest fixture, plus 0.433 psi per foot of elevation from the pump to that fixture, plus friction loss, minus the pressure already at the pump inlet. A three-story building wanting 45 psi at the top floor, 30 ft above the pump, with 30 psi at the main, needs roughly 45 + 13 + friction − 30 ≈ 28 psi of boost plus pipe losses. Read that across the tables above: 28 psi at 26 GPM lands inside the CMBE 3-62, and at 60 GPM inside the 10-54.
2. Estimate peak flow honestly
Size to simultaneous demand, not the sum of every fixture. A water-supply-fixture-unit method (IPC Table 604.3 / Hunter’s curve) converts fixture counts into a realistic peak GPM for residential work; the IAPMO Water Demand Calculator is more accurate for light commercial. The CMBE 1 family suits small homes, the 3 and 5 families most multi-bath and small-commercial work, the 10-54 up to 70 GPM, and a TWIN 10-54 reaches 141 GPM. The booster sizing calculator runs the fixture-unit method for you.
3. Check the suction condition first
CMBE runs on a flooded or pressurised suction. Grundfos states a maximum suction lift of 1 m (3.3 ft) including inlet-pipe pressure loss at 68°F, and the unit is not self-priming — so it wants a main, or a tank at or near pump level. If you are drawing up from a below-grade tank, cistern or shallow well, that is a job for the self-priming Grundfos SCALA line instead.
4. Size the tanks that are not in the box
Every CMBE arrives with its diaphragm tank fitted, so no external pressure tank is needed for a normal main-fed installation. Two cases still need sizing: a break or storage tank ahead of the pump, and the thermal expansion tank at any storage water heater, which is a code requirement independent of the booster. Size either with the pressure tank sizing calculator.
Sizing rules. Never set the pressure set point above the build’s maximum head — the panel allows it, the pump cannot deliver it. Keep the sum of inlet pressure and pump head under the 145 psi system limit. And if your duty point lands past 70 percent of a build’s head at design flow, step up a model rather than running the drive flat out.
Grundfos Selection Charts
Grundfos publishes selection tables for residential work. Find your required boost in psi and your flow range, and read the recommended model — then confirm against the pressure-added tables above.
By floors and taps
Floors
1-5 taps
6-10 taps
11-20 taps
21-50 taps
4
CMBE 1-75
CMBE 1-75
CMBE 3-62
CMBE 3-93
3
CMBE 1-44
CMBE 1-75
CMBE 3-62
CMBE 3-62
2
CMBE 1-44
CMBE 1-44
CMBE 3-62
CMBE 3-62
1
CMBE 1-44
CMBE 1-44
CMBE 3-30
CMBE 3-62
1 × 230 V — by boost and flow
PSI boost
0-15 gpm
0-25 gpm
0-30 gpm
0-45 gpm
0-55 gpm
0-65 gpm
20
CMBE 1-44
CMBE 3-30
CMBE 5-31
CMBE 10-54
CMBE 10-54
CMBE 10-54
30
CMBE 1-75
CMBE 5-31
CMBE 5-31
CMBE 10-54
CMBE 10-54
CMBE 10-54
40
CMBE 1-75
CMBE 3-62
CMBE 5-62
CMBE 10-54
—
—
50
CMBE 1-99
CMBE 3-62
CMBE 5-62
—
—
—
60
CMBE 1-99
CMBE 3-93
CMBE 5-62
—
—
—
70-80
CMBE 3-93
CMBE 5-62
—
—
—
—
1 × 115 V — by boost and flow
PSI boost
0-10 gpm
0-15 gpm
0-20 gpm
20
CMBE 1-44
CMBE 1-44
CMBE 3-30
30
CMBE 1-44
CMBE 3-30
CMBE 3-51
35
CMBE 1-44
CMBE 3-51
CMBE 3-51 *
40
CMBE 1-44
CMBE 3-51
—
50
CMBE 1-75
CMBE 3-51
—
55-60
CMBE 1-75 *
—
—
* Indicated pump may be 5-10 percent undersized on flow at the desired pressure. Charts reproduced from Grundfos CMBE literature in 10 psi steps for reference; confirm the duty point against the pressure-added tables above or the factory submittal before ordering.
What Makes CMBE Different
The engineering behind the package, and why it matters on an installation.
Complete packaged system
Five-way fitting with integrated non-return valve, diaphragm tank, outlet pressure sensor and pressure gauge are fitted at the factory. Nothing to source separately, nothing to plumb but suction and discharge.
IE5 premium-efficiency motor
The MGE motor with integrated frequency converter is a premium-efficiency IE5 design with thermal protection to TP 211 (IEC 34.11), so no external motor protection is required. Grundfos rates the drive at up to 40 percent energy savings against fixed-speed boosting.
Stainless hydraulics
Pump sleeve, shaft, impellers, chambers and nozzle in AISI 304 stainless with an AISI 316 sensor fitting — corrosion resistance that suits chlorinated, softened and raw water alike.
Structured dry-run recovery
On loss of inlet pressure the pump stops and alarms, then attempts five restarts at 10-second intervals and eight at 5-minute intervals, repeating after 24 hours — it recovers on its own when water returns.
Wide model ladder
Ten builds across four flow families mean the duty point can be matched closely instead of oversizing, from a small cottage supply to 70 GPM on one pump and 141 GPM on a TWIN.
Grundfos GO connectivity
Radio communication with the Grundfos GO app through the MI 301 module gives setup, status and operating parameters from a phone or tablet.
Drinking-water certified
Classified to NSF/ANSI 61 and NSF/ANSI 372 for potable water, and the 1 × 230 V CMBE models are UL listed as a packaged pumping system.
How CMBE Compares
We sell every major booster line, so we can be straight about fit. The single most important distinction: CMBE is a flooded-suction system, while most of the compact residential boosters below are self-priming.
CMBE vs Grundfos SCALA
Specification
CMBE
SCALA2
SCALA1
Control
Variable speed
Variable speed
Fixed speed
Flow range
to 70 GPM
to 20.7 GPM
15.8-23.5 GPM nominal
Max head
to 365 ft
147 ft
150-180 ft
Models
10
1
2
Self-priming
No (max 3.3 ft lift)
Yes, 26 ft
Yes, 26 ft
Max system pressure
145 psi
145 psi
116 psi
Max inlet pressure
Flooded suction, see manual
87 psi
43.5 / 29 psi by model
Hydraulics
Stainless AISI 304
Aluminum + composite
Composite
Noise
55 dB(A)
< 44 dB(A)
< 55 dB(A)
Multi-pump
TWIN with cascade control
Parallel twin set
Electronic twin
Typical use
Whole building, light commercial
Whole home comfort
Home, irrigation, transfer
SCALA is the compact, self-priming, quieter choice for a single residence or a tank draw, and the only one of the three that will lift water. CMBE is the larger stainless system for buildings and the only one here reaching 70 GPM or 365 ft. View the SCALA line →
CMBE vs DAB Esybox
Specification
CMBE
DAB Esybox
DAB Esybox Max
Control
Variable speed
Variable speed
Variable speed
Max flow
to 70 GPM
31.7 GPM
76 GPM per unit
Max head
to 365 ft
213 ft
to 316 ft
Self-priming
No
Yes, 26 ft
No (flooded via dock)
Max system pressure
145 psi
116 psi
174 psi nominal
Hydraulics
Stainless AISI 304
Composite/technopolymer
Stainless
Multi-pump
TWIN, cascade + alternation
Wireless to 4 units
1-4 via Esydock
Phase
Single phase
Single phase
Single or three phase
Esybox is the more compact, self-priming alternative and scales further with Esybox Max, which beats CMBE on per-unit flow and multi-pump count. CMBE counters with stainless hydraulics, a finer model ladder, more head, and a higher system-pressure rating than the standard Esybox.
CMBE vs A.Y. McDonald DuraMAC
Specification
CMBE
DuraMAC VS
DuraMAC Light Commercial
Control
Variable speed
Variable speed
Fixed speed
Flow
to 70 GPM
6-35 GPM
35 GPM
Boost / head
to 365 ft (158 psi)
25-65 psi
40-78 psi
Max system pressure
145 psi
120 psi
—
Hydraulics
Stainless AISI 304
SS 304/316
Stainless components
Self-priming
No
Yes
Yes
Multi-pump
TWIN with cascade
Single
Single
Origin
Denmark / assembled Mexico & US
Made in USA
Made in USA
DuraMAC is self-priming, domestically manufactured and typically the lower-cost route to a residential VFD booster. CMBE goes higher on head and system pressure, offers ten builds instead of two, and is the only one here with a factory twin.
CMBE vs Goulds Water Technology
Specification
CMBE
Goulds ResiBoost
Goulds Aquavar
Control
Variable speed
Variable speed
Variable speed (e-AB3 / e-AB2)
Max flow
to 70 GPM
to 35 GPM
to 80 GPM (e-AB2)
Motor
IE5, to 2.31 HP P1
0.75-2 HP
0.5-5 HP
Pump
Stainless CME multistage
Stainless e-HM
e-HM / MCS
Self-priming
No
No
No
Packaged
Fully assembled
Pre-wired, tank separate
Kit / drive package
Multi-pump
TWIN with cascade
Single
Duplex / multi-master
Install rating
IP55 pump, indoor
Indoor
NEMA 1 / NEMA 3R
The closest architectural match on this page — both are stainless multistage VFD boosters that want flooded suction. Aquavar scales higher in flow and horsepower and offers an outdoor-rated enclosure; CMBE arrives fully assembled and adds a factory twin.
CMBE vs Davey
Specification
CMBE
Davey DynaDrive
Davey EvoDrive
Control
Variable speed
Variable speed
Variable speed (PM motor)
Max flow
to 70 GPM
12-24 GPM tabulated
28 GPM
Max pressure
to 365 ft (158 psi)
87 psi max set
up to 95 psi
Max casing / system
145 psi
116-145 psi
145 psi
Self-priming
No
Flooded / limited
13 ft lift
Hydraulics
Stainless AISI 304
304 stainless
304 stainless
Multi-pump
TWIN, cascade + alternation
Daisy-chain 2 pumps
Duty/standby 2 pumps
Certifications
NSF 61/372, cULus
NSF 61 (WQA)
NSF-oriented
Davey DynaDrive and EvoDrive are strong compact options with stainless hydraulics, two-pump modes and — on the EvoDrive — 13 ft of suction lift CMBE cannot offer. CMBE reaches higher flow and head, and its TWIN adds cascade control and alternation rather than a simple pairing.
CMBE vs Franklin Electric
Specification
CMBE
FE VersaBoost Pro
FE MH Series
Type
Packaged VFD booster
Packaged VFD booster
Multi-stage bare pump
Max flow
to 70 GPM
18-25 GPM
15 / 30 / 45 GPM nominal
Max head
to 365 ft
—
—
Fluid temperature
140°F
—
225°F
Integrated tank / CV
Yes
Yes
No
Self-priming
No
No
No
Motor
IE5 with integrated VFD
Encapsulated 4 in submersible + VFD
1-2 HP, 1 & 3-phase
Multi-pump
TWIN with cascade
Single
Build custom (SpecPAK)
Install rating
IP55, indoor
NEMA 3R indoor/outdoor
Indoor/outdoor motor
VersaBoost Pro is the closest packaged competitor and adds an outdoor-rated NEMA 3R enclosure CMBE does not have; CMBE offers more models, head and flow. MH Series is a bare pump for custom stations and handles fluid to 225°F. Franklin’s Inline SpecPAK sits above the CMBE class for duplex through quadplex work.
Accessories
Genuine Grundfos accessories for the CMBE and CMBE TWIN range.
Grundfos MI 301
Bluetooth mobile interface that connects the Grundfos GO app to the pump by radio or infrared. Rechargeable, pocket-sized, ships with charger and USB cable.
Genuine Grundfos parts and service kits for the CMBE range are available to order — email sales@watermainsupply.com with your model and product number.
Why Source Grundfos CMBE from Watermain Supply
The Right US Build
CMBE single and TWIN systems in U.S. 60 Hz configurations — 115 V and 230 V, NPT connections, single units with a US plug and TWIN systems cabled for fuse-box wiring.
Engineering-Led Sizing
We size from fixture count, elevation, inlet pressure and pipe friction against the manufacturer curve — and tell you when a smaller model will do.
Multi-Brand Perspective
We also sell Grundfos SCALA, DAB, A.Y. McDonald DuraMAC, Goulds, Davey and Franklin Electric. If CMBE is not the right fit, we will say so and quote the one that is.
Twin & Building Systems
Guidance on CMBE TWIN for standby redundancy and staged flow in apartment buildings, hotels and light industrial plants.
Account Terms Available
Net-30 terms for qualified contractor, property-management and municipal accounts, handled in-house.
Parts & Aftermarket
Genuine Grundfos service kits and spares with model cross-reference, so you get the right sensor, valve or tank the first time.
Frequently Asked Questions
Common questions from plumbers, property managers and engineers specifying a CMBE booster.
Is the CMBE self-priming?
No. CMBE is designed for flooded suction, with a maximum suction lift of 3.3 ft (1 m) including inlet-pipe pressure loss at 68°F. Feed it from a pressurized main or from a tank at or above pump level. If you need to lift water from a below-grade tank, cistern or shallow well, the self-priming Grundfos SCALA line is the correct choice.
Do I need a separate pressure tank?
No. Every CMBE ships with a diaphragm tank, five-way fitting with integrated non-return valve, outlet pressure sensor and pressure gauge already fitted. Connect suction and discharge, plug it in, and set the pressure. A thermal expansion tank is still required at any storage water heater — size it with the pressure tank sizing calculator.
What do the numbers in CMBE 3-62 mean?
The first number is the nominal flow family in cubic metres per hour and the second is Grundfos’ nominal head in metres. A CMBE 3-62 is a 3 m³/h family pump with a 62 m (203 ft) head designation, and the published curve takes it to 26.4 GPM at reduced head. Read the second number as a naming convention rather than as the shut-off pressure: on the builds Grundfos draws to zero flow, the curve sits a little above the name — the 1-99 shows 365 ft against a 325 ft designation.
How much pressure does a CMBE actually add?
Every figure on this page is what the unit adds on top of the inlet, not the discharge pressure. At 26 GPM a CMBE 3-62 adds 37 psi and a 3-93 adds 55.6 psi; at 60 GPM a 10-54 adds 31.9 psi. See the pressure-added tables above for the full range, and use the booster sizing calculator to match a build to your building.
Which models run on 115 V?
Four builds are offered in 1 × 115 V, 60 Hz: CMBE 1-44, 1-75, 3-30 and 3-51. Everything else in the range is 1 × 200-240 V. Single CMBE units ship with a 4.9 ft cable and a US plug.
What is the difference between CMBE and CMBE TWIN?
CMBE TWIN is two complete CMBE pumps mounted in parallel on a common base plate with a manifold set. It adds cascade control, which stages the second pump in as demand rises, and automatic alternation, which starts whichever pump has the fewest running hours. Two pumps also hold more pressure at the flow the building draws — on the TWIN 10-54, 60 GPM is 31.9 psi added from one pump and 54.4 psi from the pair. Three systems are offered: 1-44 and 3-51 at 115 V, and 10-54 at 200-240 V, reaching 28.9, 52.8 and 140.9 GPM combined. See the CMBE TWIN systems.
How high can I set the pressure?
The set point must never exceed the build’s maximum head, which is on the nameplate; the panel will let you set a value the pump cannot deliver. The pump also cuts in at 7.25 psi below the set point, and the sum of inlet pressure and pump head must stay under the 145 psi maximum system pressure.
Do I need the MI 301 to use a CMBE?
Not to run one. The pressure set point is entered on the pump's own operating panel with the up and down buttons, and the pump runs with no app at all. The MI 301 is what lets Grundfos GO reach the pump: it pairs to your phone over Bluetooth, then connects to the pump by radio or infrared for full setup, live operating data, alarm history and firmware updates. It is sold separately and includes the charger, USB cable and quick guide.
Can I install a CMBE outdoors?
The pump carries an IP55 enclosure rating (sensor IP54) but Grundfos requires a protective cover for outdoor installation, large enough to shield the motor from direct sunlight, rain and snow. Ambient range is -4 to 131°F; provide freeze protection in cold climates.
Is CMBE certified for drinking water?
Yes. CMBE is classified to NSF/ANSI 61 for drinking water system components and NSF/ANSI 372 for low lead content. The 1 × 230 V CMBE models are additionally UL listed as a packaged pumping system.
Ready to Size Your Booster?
Send us your fixture count, number of floors, inlet pressure and required flow. We will respond with a sized CMBE or CMBE TWIN selection, accessories and lead time.
Technical data on this page is taken from the Grundfos CMBE and CMBE TWIN North America data booklet (98647967, 10.2025) and is subject to change by the manufacturer. Confirm against the current installation manual and pump curve before specifying.
Grundfos, CMBE, CME, SCALA, MGE and Grundfos GO are trademarks of Grundfos Holding A/S, used here for product identification only. DAB, Esybox, DuraMAC, Goulds, ResiBoost, Aquavar, Davey, DynaDrive, EvoDrive, Franklin Electric, VersaBoost and SpecPAK are trademarks of their respective owners, used here for product identification only.
Watermain Supply is a DBA of E4 Industrial LLC, an independent industrial supplier based in Houston, Texas.
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