Flex 24V Stack Pack 2.5-Gallon Wet Dry Vacuum

Round Off Your Stack Pack Build With Flex’s First Storage-Compatible Vac

While Flex’s 24V system isn’t as deep as other cordless platforms, it’s home to pretty much every core tool. This includes shop vacs. Until now, Flex users were limited to a single 1.6-gallon model. I’m looking at the newest addition to the brand’s cleaning solution lineup, the Stack Pack-compatible FX5231. I’ll walk you through what upgrades this 2.5-gallon vac brings for Flex users and who it’s a good fit for.

Buy at Acme Tools

Read:
Best Shop Vac and Wet-Dry Vacuums

Pros

Stack-Pack compatible
Onboard attachment and hose storage
HEPA filter
Good performance level for its size

Cons

Smaller capacity than other cordless vacs
A bit expensive

Flex Stack Pack 2.5-Gallon Wet Dry Vacuum Performance

Capacity and Cleaning Power

As Flex’s second-iteration wet-dry vacuum on the 24V battery platform, the FX5231 features a 2.5-gallon tank. That adds nearly a gallon to their first-generation 1.6-gallon vac, the FX5221, which earned our pick for the best small shop vac.

The FX5231 achieves air volume levels of up to 63 CFM, with a top water lift of 82 inches. For its size, these are respectable numbers, ideal for cleaning medium-sized wet and dry messes around your work area.

To put it into perspective, the first-gen model achieved up to 41 CFM and 42 inches of water lift, so the new vac is a nice upgrade in both capacity and performance for Flex users. Even comparing it against the Milwaukee 2.5-gallon Packout wet/dry vacuum, Flex’s model achieves higher performance metrics, outpacing it by 13 CFM and 35 IOW.

Battery and Runtime

This vacuum is powered by a Flex 24V battery. Using an 8.0Ah pack, Flex estimates runtimes of up to 60 minutes on the lowest setting. Note that there aren’t any kit configurations at this time, so be sure you have a Flex 24V battery and charger in your arsenal.

There are two power levels to choose from—standard (ECO mode) and turbo mode. To toggle between each mode, turn the vacuum on with the power button, turn on the vacuum setting with the start/stop button, and then press the turbo button to switch between the two speed settings.

HEPA Filter

The FX5231 vacuum is equipped with a HEPA filter that filters out up to 99.97% of particles. There’s a manual filter-cleaning push-button control to clear debris buildup and maintain optimal suction, extending the filter’s life.

Flex Stack Pack 2.5-Gallon Wet Dry Vacuum Design

Stack Pack Compatibility

Perhaps the main talking point about this Flex vacuum is its compatibility with the Stack Pack storage lineup. It attaches to select pieces in the Stack Pack roster for easy transportation and organization with the rest of your tool storage buildout.

Attachments and Onboard Storage

This vacuum includes three attachments: a crevice tool, a utility nozzle, and a utility nozzle brush. All three nozzles are stored within a covered compartment onboard the vacuum. I like that the compartment is divided to fit each attachment precisely, making it easy to identify and store.

The 1 1/4-inch-diameter vacuum hose expands up to 6 feet in length. There’s an adapter slot on the outside of the unit that stores your nozzle adapter while it’s not in use. The hose also stores onboard, and Flex includes two hose brackets to attach it to the outside of the unit when you’re not using it.

There’s also a shoulder strap that hooks onto loops on opposite corners of the vacuum to help you carry it more easily when it’s not attached to a rolling Stack Pack build.

Model FX5231A includes a Bluetooth remote control that lets you start/stop the vacuum and change the speed right from the end of the hose. Interestingly, the remote is equipped with vibration detection, which automatically turns on the vacuum when the hose is connected to a power tool for dust extraction.

This is a feature we haven’t seen in most other vacuums. Many brands implement a remote function into their design, but the closest we’ve seen to Flex’s vibration detection technology is Metabo’s (now discontinued) CordlessControl, which features a vibration detection function similar to what Flex implemented here.

To test Flex’s vibration detection claims, I hooked the vacuum hose up to the Skil SR7603 20V orbital sander’s dust port. The vacuum turned on as soon as we powered up the sander. By design, the vacuum shuts off around 5 or 6 seconds after you power down your tool to ensure it removes all of the dust from the tool and hose.

Flex Stack Pack 2.5-Gallon Wet Dry Vacuum Price

This vacuum retails for $229 as a bare tool. There are currently no kit options available, so make sure you have a Flex 24V battery and charger if you’re not already on this platform. Flex backs your purchase with a 3-year warranty, or a 5-year warranty when you register your product within 30 days of purchase.

Should You Buy It?

The shop vac market is fairly well-saturated, with most power tool brands having a few models in their rosters. For Flex users, however, this is only the second wet/dry vacuum on the 24V system, and it’s the highest-capacity model in the lineup at 2.5 gallons. Plus, it’s compatible with your Stack Pack storage build, so you can easily transport it with the rest of your tools.

While it’s not the most powerful vac we’ve seen, it’s still ideal for medium-sized wet and dry messes on the jobsite for existing Flex 24V users. However, for those after something larger or stronger, the FX5231 is where this platform currently tops out. If you need more, consider a model from another brand for now, or wait to see what’s next from Flex.