Tornado® OB 28/20 Walk-Behind Orbital Floor Scrubber, 28 Inch, 20 Gallon

It's 10 p.m. and your crew has 40,000 square feet of school hallway, gym lobby and cafeteria to scrub before the buses show up. With mops, that's the whole night and then some. The Tornado OB 28/20 is a walk-behind orbital floor scrubber with a 28 x 14 inch rectangular pad that vibrates at 3,530 RPM under up to 132 lb of down pressure, and a traction drive that pulls the machine along so your operator only steers.

Tornado rates it at 33,906 square feet an hour in theory. Take off 30 to 50% for turns, refills and emptying, and you're still at roughly 17,000 to 23,700 square feet an hour, which puts that 40,000 square foot route at about 2 to 2.5 hours on a battery charge rated for 3 to 4 hours. The 20-gallon solution tank and 22-gallon recovery tank mean fewer trips to the mop sink along the way.

Tornado backs it with 4 years on parts, 10 years on the rotomolded body, a lifetime warranty on the vibration isolators and 2 years on labor. We're an authorized Tornado retailer, so that coverage is yours from day one.

Which One Do I Need: Machine Only, Lead Acid or AGM?

Every version is the same OB 28/20 with the same onboard charger. What changes is whether batteries come installed, and which kind. The machine runs on four 6-volt batteries wired for 24 volts.

Choose Your Battery Type

Machine Only

For fleets that already
stock their own batteries.

Lead Acid (4 x 6V)

Lowest cost to get running.
Needs regular watering.

AGM Sealed (4 x 6V)

Sealed, no watering.
Costs more up front.

• Lead acid if you want the lowest total price and someone on your team will check the water. Tornado's manual asks you to check the electrolyte every 20 charges and top up with distilled water after charging, never before. Our guide to maintaining flooded lead acid scrubber batteries covers the routine.

• AGM if nobody on the night crew should be opening battery caps, or the machine charges somewhere you don't want acid fumes. It's sealed and needs no watering, in exchange for a higher price. See how to look after AGM scrubber batteries.

• Machine only if you already buy batteries in bulk or have a battery supplier you like. The compartment takes four 6 V batteries in series and measures 15 x 20 x 11 in. One catch: the machine leaves the factory set for flooded lead acid, and Tornado's manual says an authorized technician has to change that setting before gel batteries go in. If you plan on sealed batteries of any kind, check with us or Tornado first.

Still weighing battery types? Our comparison of lead acid, AGM, TPPL and lithium scrubber batteries goes deeper. Tornado doesn't offer a TPPL package on this model.

OB 28/20, OB 20/14 or BD 26/20?

The Tornado OB 20/14 is the smaller orbital brother, and the Tornado BD 26/20 shares the OB 28/20's body, tanks and squeegee but spins a round disk instead of an orbital pad.

Figures from the Tornado spec sheets and our OB 20/14 and BD 26/20 product pages.

Pick the OB 20/14 if your floors are broken up into classrooms, restrooms and offices, or your elevator and storage closet are tight. It costs less and fits smaller spaces. Pick the BD 26/20 if the job is routine scrubbing of large open floors and you'd rather use standard disk brushes and pads. Pick the OB 28/20 for large open floors where you also want the orbital head's square edge in the corners and its heavier scrub for finish work.

Not sure which size fits? Send us your square footage, floor type and cleaning schedule, or call (855) 601-5678, and we'll tell you which scrubber fits, including when the answer is the smaller one.

The Owner's Insights on the OB 28/20

What I like about the OB 28/20 is that the pad doesn't spin. It vibrates in tiny circles, so there's no torque pulling the machine sideways the way a big disk can, and the square front edge gets into corners a round brush leaves for the mop. Pair that with a traction drive and your operator is steering, not wrestling, which matters on a two-hour route.

Now the honest part. This is a big walk-behind: 60 inches long, 39 inches across the squeegee and 348 pounds before four batteries go in. Measure your doorways, elevator and storage spot before you order. If most of your square footage is small rooms, the OB 20/14 will get more use. And on finish removal, Tornado says the high-speed orbital action can strip without chemicals. I'd treat that as something to test on your own floor, with the right pad, before you promise a client a chemical-free strip. More on that below.

Why You'll Love the Tornado OB 28/20

• 28 x 14 inch orbital pad at 3,530 RPM. The rectangular head scrubs right up to walls and into corners, and non-marking bumper wheels keep it off the baseboards.

• Adjustable down pressure up to 132 lb. A wing nut sets it, so you can go light for daily scrubbing and heavier on a worn traffic lane.

• 300-watt traction drive with two speed settings. It climbs ramps up to a 10% grade, and a parking brake holds it on a slope or in a van.

• 20-gallon solution and 22-gallon recovery tanks. The extra 2 gallons of recovery space gives foam somewhere to go, and a float shuts the vacuum off before water reaches the motor.

• Hinged recovery tank. It tilts back for a complete drain and props open on a piston, so you can reach the batteries and vacuum motor without lifting anything.

• Vibration isolators with a lifetime warranty. Less shake reaches the operator's hands over a long route.

What an Orbital Scrubber Does Differently, and the Chemical-Free Question

A disk scrubber like the BD 26/20 spins a round brush at 160 RPM. An orbital head moves a flat pad in very small, very fast orbits, here 3,530 times a minute. The result is a lot of scrubbing action with less solution on the floor, which is why Tornado says the OB 28/20 cuts water and chemical use in daily cleaning and dries faster. Our guide to disk, cylindrical and orbital scrubber heads explains when each one fits.

Tornado also markets the OB 28/20 for chemical-free floor finish removal, and lists a 14 x 28 inch black stripping pad (BK1428) for it. The operator manual, though, has no stripping procedure, and for everyday scrubbing it calls for a low-foam detergent. How well a water-only strip works depends on the finish, how many coats are down and the pad you use. If stripping is the main reason you're buying, tell us your finish and floor type first and we'll check with Tornado before you order.

How to Set Up and Care for Your OB 28/20

Sweep or dust mop first; the manual is clear that the scrubber isn't for loose debris. Fill the solution tank through the large fill port, watching the sight tube, and use a low-foaming, non-flammable cleaner. Fit the pad by raising the base with its switch, sliding the pad underneath and lowering the base onto it. Turn the key, switch on the vacuum, lower the head and squeegee, and squeeze the drive levers: the pad and solution start as the machine moves and stop when you let go. Our step-by-step on how to use a floor scrubber covers passes and overlap.

At the end of the shift: drain and rinse the recovery tank, clean the suction filter and the pad, and wipe the squeegee blades. Clean the inline solution filter every week or so, and close the solution valve first or the tank drains out through it. The rear squeegee blade has four usable edges, so flip it before you replace it. Plug the onboard charger into any standard outlet with the recovery tank raised, and allow 8 to 10 hours for a full charge. Never leave the batteries flat for more than two weeks.

Watch the OB 28/20 in Use

Tornado's training video covers the OB 28/20 together with the BD 26/20 and BD 30/20, which share its body, tanks and squeegee. The video below starts at that section.

What the Tornado Warranty Covers

Under the Tornado Commercial Limited Warranty (revised January 21, 2025), the OB 28/20 is covered for 4 years on machine parts, 10 years on the rotomolded body, a lifetime on the isolators and 2 years on labor. Batteries supplied in the lead acid and AGM packages carry a pro-rated battery warranty. Wear items such as pads, squeegees, filters and hoses aren't covered, and Tornado prepays ground freight both ways on eligible claims. Register the machine within 30 days of purchase. The full terms are in the downloads below.

Why You Should Consider a Tornado Floor Scrubber

Tornado Industries, part of Tacony Corporation, has built commercial floor care equipment for more than 90 years and supports it through a US network of authorized service centers. Its scrubber line runs from compact 14-inch machines to ride-ons, so parts, pads and service stay with one brand as your floors grow. See all our orbital floor scrubbers or the full Tornado floor scrubber range.

Tornado OB 28/20 Specifications