Tornado® BDSO 20/21 Stand-On Floor Scrubber, 20 Inch, 21 Gallon, Battery Powered

Which One Do I Need?

Picking the battery option

Every version is the same machine with the same on-board charger. The only thing that changes is what sits in the battery tray: two 12-volt batteries wired for 24 volts.

• No Battery (Machine Only) if you already have batteries or buy them locally. The battery tray measures 14 x 13 x 11.5 in, so check that yours fit, and you set the battery type in the machine's menu before the first charge. Tornado warns that the wrong setting can ruin the batteries.

• Lead Acid Battery (2 x 12V) for the lowest price with batteries included. They're flooded batteries, so someone has to check the water level every 20 charges or so and top up with distilled water. If nobody on your crew will do that, skip this one.

• AGM Sealed Battery (2 x 12V) if you want sealed, no-watering batteries for about $150 more than lead acid. A good fit for schools and offices where the machine is stored in a closet and nobody wants acid near it.

• TPPL Sealed Battery (2 x 12V) if the machine runs every night. They're sealed like AGM and carry Tornado's 3-year replacement warranty instead of the pro-rated battery terms on the other two.

Our guide to floor scrubber batteries: lead acid, AGM, TPPL and lithium goes deeper if you want the full comparison.

Picking the machine: BDSO 20/21, BD 20/11L or BDSO 27/28

• BDSO 20/21 (this page) for hard floors with narrow aisles, doorways and tight corners: grocery and convenience stores, school hallways, clinics, small warehouses. At real-world speed, 3 hours of scrubbing covers roughly 33,000 to 46,000 square feet. It's the smallest stand-on in the Tornado range.

• The Tornado BD 20/11L walk-behind if your floor is smaller or your budget is tighter. Same 20-inch disk and 48.5 lb of pressure, costs less than half as much, weighs 320 lb with batteries instead of 540 lb, and fits in a smaller closet. The trade-off is your operator walks the whole shift and the tanks are smaller.

• The Tornado BDSO 27/28 stand-on if your aisles are wide and your floor is large. Its 27-inch path and 28-gallon recovery tank cover more floor per charge and per dump, but it needs a 65-inch turning circle instead of 53 and weighs 760 lb with batteries.

How the BDSO 20/21 Compares

Figures from Tornado's spec sheets and product pages, the specifications on our BD 20/11L and BDSO 27/28 pages, and the Tornado Commercial Limited Warranty (January 2025).

Not sure this is the right size? Send us your square footage, floor type, narrowest aisle and cleaning schedule, or call (855) 601-5678, and we'll tell you which machine fits, including when the answer is the walk-behind. Our guide on walk-behind vs ride-on floor scrubbers covers the same question in more detail.

The Owner's Insights on the BDSO 20/21

The case for this machine is the operator, not the spec sheet. A 20-inch walk-behind and this stand-on scrub the same width with the same pressure. What changes is that your operator isn't walking 3 hours a night, so the last hour of the shift looks like the first. It drives with a forward and reverse lever and a foot pedal on the platform. Step off and it stops, and the parking brake holds it where it is.

A few things I'd want to know before buying. It arrives on a pallet and weighs 540 lb with batteries, so you need a forklift, a dock or a ramp to get it off; Tornado doesn't include a ramp. The machine won't back up with the squeegee down, which takes a shift or two to get used to. And a single 20-inch disk is a maintenance machine, not a stripping machine. If your floor needs heavy restorative scrubbing every night, look at the BDSO 27/28 with 126 lb of pressure instead.

Why You'll Love the BDSO 20/21

• 53-inch turning radius and a 27.5-inch-wide body. It fits through standard doorways and turns at the end of narrow aisles where a ride-on has to back out.

• Squeegee that swings 90 degrees both ways. The 27-inch squeegee follows the machine through turns, so the floor behind you stays dry instead of leaving a wet arc on every corner.

• Automatic mode on the drive pedal. Press the pedal and the brush drops, water flows and the vacuum starts; release it and everything stops, so no puddles form while you're parked.

• 14.5-gallon solution tank and 21-gallon recovery tank. Fewer trips to the janitor's closet than a 20-inch walk-behind, and the fill hose connects straight to a faucet.

• Under 70 dB with a silent vacuum mode. Normal conversation is about 60 dB, so it can run in a store or clinic while people are still around.

• On-board charger and pad holder included. Plug it into a standard 115 V outlet at the end of the night; a full recharge takes 8 to 10 hours.

How to Set Up and Care for Your BDSO 20/21

Fill the solution tank with clean water no warmer than 104°F (40°C) and a low-foam floor chemical at the label's dilution. Tornado's manual gives 122°F in one place and 104°F in another, so we go with the lower number. Add a little defoamer to the recovery tank before you start, and never use pure acids or solvent cleaners. The level hose at the back shows how much solution is left while you work.

Plan to scrub level floors. Tornado's safety rules say not to use it on slopes over 2 percent, even though the technical table lists a 10 percent maximum gradient. If your route includes ramps, call us and we'll confirm with Tornado before you order. Top speed is 2.5 mph, and you can set a lower maximum from the dashboard for new operators.

At the end of the night, run the break washing mode for about 15 seconds so the squeegee dries the last strip and clears the hose. Then drain and rinse the recovery tank, clean the vacuum filter, rinse the brush or pad and wipe the squeegee blades. Weekly, check the rear squeegee blade and flip or replace it, and clear the squeegee hose. If you run flooded lead acid batteries, check the water level every 20 charges and never leave them discharged for more than two weeks. Our step-by-step guide to using a floor scrubber and our floor scrubber troubleshooting guide cover the rest.

The machine comes with a pad holder (part 48802010) for 20-inch pads. Tornado also lists 20-inch brushes for different floors: PPL 0.3 for irregular floors with deep joints (48902010), PPL 0.6 for normal floors (48902050), PPL 0.7 and 0.9 for smooth floors with stubborn dirt (48902020, 48902030), a Tynex grit brush for tough, very dirty floors (48902040) and a 5-mix brush for all floor types (48902060). Replacement squeegee blades are 48417010 (front) and 48417030 (rear). Ask us for any of them.

What the Tornado Warranty Covers

Under the Tornado Commercial Limited Warranty (January 2025), the BDSO 20/21 is covered for 4 years on parts, 10 years on the rotomolded parts and 2 years on labor. Lead acid and AGM batteries are replaced if they fail within 90 days, then pro-rated after that. TPPL batteries carry a 3-year replacement warranty. Repairs go through an authorized Tornado service center, and wear parts such as brushes, pads and squeegee blades aren't covered. Tornado asks you to register the machine within 30 days. The full terms are in the downloads below.

Why You Should Consider a Tornado Floor Scrubber

Tornado Industries is part of Tacony Corporation, which also owns Powr-Flite, and its scrubber range runs from 17-inch compacts to 33-inch ride-ons. The BDSO 20/21 takes the same 20-inch pads as the BD 20/11L walk-behind, so a facility that runs both stocks one pad size. See all our stand-on floor scrubbers or the full Tornado floor scrubber range.

Tornado BDSO 20/21 Specifications