The WhisperFlo VST is Pentair's larger variable-speed pump for in-ground pools: 2.6 total horsepower, and Pentair says it offers more power than the SuperFlo VST. This review is research-based: we did not test the pump. It works from Pentair's own installation manual and product page, with the Amazon listing for the EC-011533 version. No prices, and no star ratings or customer reviews copied across.
| Model | 011533 (dealer) / EC-011533 (online) |
|---|---|
| Total horsepower | 2.6 THP |
| WEF | 8.4 |
| Speed range | 450 to 3,450 RPM |
| Input voltage | 115 to 230 V nominal, 50/60 Hz |
| Full load amps | 13.9 / 11.1 to 10.1 A |
| Ports | 2 in. x 2 in. |
| Motor | Permanent magnet, TEFC |
| Weight | 45 lbs |
| Listings | UL, NSF/ANSI 50, ENERGY STAR certified |
Specifications: Pentair's WhisperFlo VST product page and the WhisperFlo VS / VST Installation and User's Guide (P/N 074167 Rev. A), checked October 2026.
A strong variable-speed pump for in-ground pools that need real flow and head: a large pool, long pipe runs, a heater or water features. Pentair's manual gives the full programming and wiring detail, and it runs on 115 or 230 V without rewiring. For an average pool with a simple setup, a smaller variable-speed pump may be all you need (our view).
- Pool type
- In-ground
- Size
- 2.6 THP
- Speeds
- 450 to 3,450 RPM, programmable
- Plumbing
- 2 in.
Is the WhisperFlo VST a good fit for your pool?
Good fit if
- You have a larger in-ground pool, long pipe runs, a heater or water features that need more flow and head
- You are replacing an existing Pentair WhisperFlo pump
- You want a pump that runs slow for filtering and fast when needed
- You want ENERGY STAR certification
Look elsewhere if
- You have an above-ground pool
- Your pool is small with a simple filter-only setup (a smaller pump may do)
- You want plug-and-play with no electrician (it must be hard-wired on a GFCI circuit)
What 2.6 THP means here
2.6 total horsepower puts the WhisperFlo VST at the larger end of residential pumps (our view). Pentair says it offers more power than its SuperFlo VST. Because it is variable-speed, size matters less for energy than with a single-speed pump: you can run it slowly most of the day (our explanation). Pentair's manual says the pump is intended to run at the lowest speeds needed to keep the water sanitary, and that finding the best settings for your pool may take some trial and error. How to find yours: how a variable-speed pool pump works.
Still, bigger is not automatically better. Choose by the flow and head your pool needs (our advice): work out the flow from your pool volume and turnover time, consider what adds resistance (long pipe runs, a heater, water features), and check your filter's maximum flow so you can't push more water through it than it is rated for. For a standard pool that needs up to a 1.5 hp pump, Pentair's smaller SuperFlo VST (342002) is the better-sized option (our view). A pressure-side cleaner is not a reason on its own: many of them use a separate booster pump (see which pool cleaners need a booster pump). Sizing: what size pool pump do I need.
Programming and the default schedule
The drive has three programmable speeds plus a Quick Clean mode, an onboard clock, an adjustable priming mode and a keypad lock. Out of the box it runs Pentair's default schedule: 3,000 RPM for 2 hours from 8:00 am, 1,400 RPM for 10 hours, 2,200 RPM for 2 hours, then a 10-hour pause. Pentair says this default is designed to give sufficient daily turnover for a typical pool. It also keeps the clock for up to 24 hours in a power outage.
Wiring: 115 or 230 V, and the details that matter
According to the manual, no wiring change is needed to run the pump on 115 V: the same terminals are used, and on lower voltage the drive automatically regulates the speed to keep the current below 13.6 A. It must be connected to a GFCI-protected circuit, permanently grounded and bonded. Pentair also notes it offers a 2-pole 20 amp GFCI breaker. Have an electrician do this (our advice). Background: pool pump voltage, 115V vs 230V.
Automation: one setting to know
The pump can be run by its own keypad, by a Pentair control system through its communication port, or by external low-voltage signals. One detail from the manual that saves a support call: control systems with older firmware may require the pump to be set as "IntelliFlo VS", and it will not respond if it is set as a variable-flow (VF) or variable speed/flow (VSF) pump.
Installation requirements from Pentair
- At least 5 ft from the inside wall of the pool (9.8 ft in Canada).
- At least 3 ft from a heater outlet.
- Not more than 5 ft above the water level.
- Short, direct suction and return piping, in a ventilated spot out of sprinklers and gutter downspouts.
- Never run it dry: the shaft seal will be damaged.
Sources
- Pentair WhisperFlo VST product page (THP, WEF, amps, ports, weight, drop-in replacement, more power than SuperFlo VST)
- Pentair WhisperFlo VS / VST manual (speed range, default schedule, 115 V operation, installation distances, automation setting)
- ENERGY STAR certification record (WhisperFlo VST)
- Pentair SuperFlo VST 342002 product page (SuperFlo VST for pools needing up to a 1.5 hp pump)
The trade-offs
What we like
- 2.6 THP for pools with heaters, features or long pipe runs
- Variable speed from 450 to 3,450 RPM with Quick Clean
- Runs on 115 or 230 V without rewiring
- WEF 8.4 and ENERGY STAR certified
- Pentair publishes a detailed manual
Worth knowing
- More pump than a small, simple pool needs
- Hard-wired install on a GFCI circuit: electrician work
- Check that your filter can handle its maximum flow
Who should buy the WhisperFlo VST?
Buy it if
- You have an in-ground pool with heating, features or long pipe runs
- You are replacing a Pentair WhisperFlo and want the same plumbing footprint
- You want variable-speed savings and room for high-flow jobs
Skip it if
- Your pool is above-ground
- Your pool is small and only needs filtering
Consider something else if
- Pairing it with a large sand or cartridge filter: check the filter's maximum flow against the pump's top speed first
Common questions
Is the WhisperFlo VST a drop-in replacement for an old WhisperFlo?
Pentair describes it as a drop-in replacement for existing Pentair WhisperFlo pumps. Check your plumbing and electrical against the manual before swapping.
Can it run on 115 volts?
Yes. The manual says no wiring change is needed for 115 V nominal power; the drive regulates the speed on lower voltage to keep the current below 13.6 A.
What is the difference between 011533 and EC-011533?
Pentair lists 011533 as available through dealers and EC-011533 as the version sold online.
What speed range does it have?
450 to 3,450 RPM, according to Pentair's manual.
Is it ENERGY STAR certified?
Pentair's product page shows it as ENERGY STAR certified.
What we could not confirm
Honest gaps. We do not state these because we could not confirm them from Pentair's documents.
- Warranty terms (Pentair refers to pentair.com/warranty)
- Flow in GPM at specific speeds for your plumbing
- Noise level in decibels (whisper is in the name, but we found no measured figure)
Our verdict
A capable, well-documented variable-speed pump for in-ground pools that need more than basic filtering. It is a sensible choice to replace an old WhisperFlo or to run a heater, features or long pipe runs, with the low-speed savings of a variable-speed motor. For a small, simple pool it is more pump than you need. We do not give pumps a Fit Score; this verdict is based on Pentair's specifications and manual.
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