Aquastrong Smart 45
An all-in-one inverter booster sold direct by Aquastrong for a house on weak city pressure. A cheaper alternative to a SCALA2 if you accept a louder pump.
Amazon $711$711
3.0/5
The benchmark compact inverter booster for a house of up to three floors and eight taps on weak city pressure. Pay for it when quiet running and steady showers matter more than price.
- 148 ft (64 psi)Head
- Variable speedDrive
Check price at Amazon$879
Price checked November 2, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Holds one set pressure at the taps, so a second shower barely changes the first
- Quiet enough for a closet off a living space, rated under 47 dBA in typical use
- Plugs into a standard outlet and ships with the tank, check valves and controller built in
- Stops itself on running dry and on motor overheating, so a lost supply will not wreck it
Cons
- Grundfos publishes no maximum flow, only a 13.2 gpm rated point, so size it against the curve
- Costs several times what generic inverter boosters sell for
- Liquid limit of 113 F rules it out for boosting hot water lines
The Grundfos SCALA2 family
Every Grundfos SCALA2 model we rank, smallest first. Ratings compare each against its own drive.
| Model | Flow | Rating | Price |
|---|---|---|---|
| Grundfos SCALA2 3-45 115V (this one) | - | 3.0/5 | $879 |
| Grundfos SCALA2 3-45 230V | - | 3.0/5 | $1,357.20 |
How it scores
The rating comes from 6 measured or published factors, each scored 0-100 against fixed reference points for its drive. How we rank explains each one.
Specifications
| Model number | 98562818 |
|---|---|
| Pumping | |
| Drive | Variable speed |
| Maximum head | 148 ft (64 psi) |
| Highest inlet pressure | 87 psi |
| Input power | 560 W |
| Ports | 1 in |
| Protection and build | |
| Built-in tank | Yes |
| Dry-run protection | Yes |
| Overheat protection | Yes |
| Outdoor rated | Yes |
| Voltage | 120 V |
| Noise | 47 dBA |
| Weight | 22 lb |
| Warranty | 2 years |
Alternatives in this drive
DAB Esybox Mini3
#10 in Variable speedFull review
A compact, quiet inverter booster for a single home that wants a large pressure range and room to add a second pump. Check the voltage and shop around on price.
Amazon $1,547$1,547
Grundfos SCALA2 3-45 230V
#12 in Variable speedFull review
The same quiet SCALA2 for a pump room wired for 240 V. Buy the 115 V version unless 240 V is all you have.
Amazon $1,357.20$1,357.20
Compare
Compare the Grundfos SCALA2 3-45 115V with any other water pressure booster pump →
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