Can You Store a Floor Scrubber in Freezing Temperatures, and How Do You Winterize It?

Key takeaways

• Only if your manual allows it. Tennant manuals give a freeze protection procedure for storage in freezing temperatures, while Clarke's CA30 20B manual and the Dura 17 manual set storage at 0 to 40 C (32 to 104 F) and Kärcher wants a frost-free room.
• To winterize, drain both tanks and the solution filter, then run full-strength propylene glycol RV antifreeze through the solution system until it shows. Tennant uses 1 gallon on walk-behinds and 2 gallons on the T16 rider.
• Water breaks the machine, but a charged battery will not freeze. Trojan's table puts a fully charged flooded battery at -92 F, while one at 20 percent charge freezes at +19 F.
• Recharge stored lead-acid batteries on the manual's schedule: monthly on the Tennant T5 and T600 and the Kärcher BD 35/15, every 2 to 3 months on the Tennant T260, every three months on the T16.
• Lithium packs can sit in the cold but cannot be charged in it. Flux Power's C48 charges only from 32 F to 113 F (0 to 45 C) unless it has the optional heaters.

You can store a floor scrubber in freezing temperatures only if its manual allows it, and only after you winterize it. Drain the solution and recovery tanks, empty the solution filter, then run full-strength propylene glycol RV antifreeze through the solution system until it comes out at the scrub head. Charge the batteries fully before you leave and keep them charged. If your manual sets a storage range that stays above freezing, as Clarke, the Dura 17 and Kärcher do, the answer is a heated room, not antifreeze.

Two answers circulate. One says never let a scrubber sit below freezing. The other says empty tanks are enough. Neither holds on its own. The manuals disagree, so the rule for your machine is in its manual, and empty tanks still leave water in the filter bowl, solenoid valve, pump and hoses. The battery is the part people forget: a charged lead-acid set will not freeze in any garage, but a flat one can freeze at +19 F.

What 12 scrubber manuals say about cold storage

We read the storage section of each operator manual.

The Trusted Clean Dura 17 manual uses the same 0 to 40 C wording as the Clarke and the same warning about moving the machine below freezing.

Two things stand out once the manuals sit side by side.

• There are two camps. Tennant gives an antifreeze procedure for storage in freezing temperatures. Clarke, Dura and Kärcher set storage above freezing and give no antifreeze step. If your manual is in the second camp, antifreeze protects the plumbing but does not make cold storage approved.
• The widest storage range is not a winterizing instruction. Minuteman's E14 allows storage down to -25 C (-13 F), but the manual gives no freeze procedure. That range describes the machine, not water left inside it. Drain it first.

How to winterize a floor scrubber, step by step

This is Tennant's procedure, with the extra steps from its rider manual. Machines with no antifreeze procedure get steps 1 to 4 and then go into a heated room.

1. Charge the batteries fully. Every manual that addresses batteries says to store them charged. Water flooded batteries after the charge (see our watering guide).
2. Drain and rinse both tanks. Empty the recovery tank at a sanitary drain, as covered in where to dump floor scrubber water, then drain and rinse the solution tank.
3. Empty the solution filter. The T600 manual has you empty the water from the solution tank filter under the machine and replace the filter. Filter bowls can crack when they freeze full, one of the causes our scrubber leaking water guide lists.
4. Clear the line to the solenoid. On the T16, Tennant has you disconnect the hose at the solenoid valve inlet, let it drain, and blow it out with 2 to 4 psi of compressed air, wearing eye and ear protection. On the small T1 Battery, emptying the tank and running the machine for about 15 seconds is the whole purge. Our solenoid and filter guide shows where these parts sit.
5. Pour in the antifreeze undiluted. Use propylene glycol based RV antifreeze: 1 gallon (4 liters) on Tennant walk-behinds, 2 gallons (7.6 liters) on the T16 rider. The T5 and T3 manuals say "at full strength. Do not dilute."
6. Run the solution system until antifreeze shows. Turn the machine on, set solution flow to its highest setting, and run it until the red antifreeze appears at the scrub head or on the floor. Then switch off. If the machine has a spray wand, run the wand for a few seconds to protect the pump. Machines with ec-H2O or FaST systems have extra steps in their manuals to cycle antifreeze through those modules.
7. Leave the remaining antifreeze in the tank. The T16 manual says it "does not need to be drained."
8. Park it right. Store it indoors and dry, out of rain, with the squeegee and scrub head raised and the recovery tank lid open for air. Tennant also asks for a rodent and insect free space. On the T600, T5 and T16, disconnect or remove the batteries if the manual says to.

Why RV antifreeze, and what the -50 F label means

Tennant's manuals name propylene glycol based RV antifreeze, the kind sold for camper and boat plumbing. None of the manuals we read names automotive coolant. The figure on the jug is a burst rating, not a freeze point. Star brite, which makes these products, explains that a product labeled for burst protection to -50 F "may start to freeze at a higher temperature, but it won't expand enough to damage a copper pipe until it reaches -50°F." Slush in the lines does not mean the protection has failed. Water you add does weaken the mix. That is why the manuals say full strength.

Bringing the machine back into service

Antifreeze has to come out before the first scrub. The T16 procedure: drain all antifreeze from the solution tank, rinse the tank, pour in 3 gallons (11.4 liters) of cool clean water, and run it through the system at full flow until the antifreeze is gone. Run the wand too if there is one. The T600 adds the spray nozzle to the flush. Collect what you drain. KOST USA, which makes RV antifreeze, tells users to dispose of spent product properly and to ask the state or local authority how. If the first scrub after storage gives you a weak or uneven spray, check the filter and solenoid before anything else, using our no solution flow checklist.

Batteries in the cold: the freeze points by state of charge

A lead-acid battery freezes because its electrolyte turns into weaker acid as it discharges. Trojan's deep-cycle storage paper prints these freeze points, taken from the BCI Battery Service Manual:

A charged set is safe in any building a scrubber is likely to sit in. A set parked at the end of a shift with a low battery light is not. At 20 percent it freezes at +19 F, a temperature an unheated warehouse can reach on a winter night. Trojan warns that freezing "usually results in irreparable damage to the plates and containers."

Cold also helps, and this is the number most storage advice misses. Trojan's stand loss test on its T-105 battery measured specific gravity falling by 0.0015 per week at 42 F, 0.005 per week at 75 F and 0.0075 per week at 86 F. Trojan, citing Battery Council International, says to give a freshening charge when specific gravity drops 0.040 points, or when a 6 volt battery reads below 6.2 volts (12.4 volts for a 12 volt battery). From those figures, a T-105 reaches that point in about 27 weeks at 42 F, 8 weeks at 75 F and 5 weeks at 86 F. That is one battery model under test, but it shows why a machine stored warm needs charging more often than one stored cold. Trojan's quick-start guide sets the practical rule: check specific gravity or voltage every 4 to 6 weeks (every 2 to 4 weeks above 90 F), boost charge at 70 percent or less, and recharge before use. Our battery maintenance guide has the full storage routine by battery type.

Lithium packs: store cold, charge warm

With lithium packs the limit that matters in the cold is charging. Flux Power's C48 floor cleaning pack lists a charge range of 32 to 113 F (0 to 45 C) and a discharge range of -4 to 131 F (-20 to 55 C), with integrated heaters offered for cold applications. A machine stored in a 20 F garage will run but will not take a charge until it warms up. If the charger shows nothing in the cold, our battery not charging guide covers the low temperature lockout. The lithium vs lead-acid comparison covers how this affects fleets that live in unheated docks.

Where this stops applying

• Your manual overrides this page. If it gives a storage range above freezing, store the machine warm whatever antifreeze you have.
• Operating is not storing. Tennant's T600 manual says not to operate below 36 F (2 C). The T5 manual says not to run scrubbing functions below freezing. To scrub a cold room, you need a different setup, set out in our freezer floor guide.
• Transport counts. Clarke and Dura warn that tank and hose water can freeze when the machine is moved below 0 C. A machine on an open trailer in winter needs the same draining as a stored one.
• Combustion machines. Propane and diesel scrubbers also have engine coolant, fuel and oil storage steps that are outside this page. Follow the engine section of the manual.
• Short stops. None of this applies to a machine that sits a weekend in a heated building. For seasonal sites like schools, put winterizing on the preventive maintenance schedule so it happens before the first frost, not after.

Frequently asked questions

Sources

• Tennant T600 EE Operator Manual 9016606 Rev. 01 (02-2023): tennantco.com
• Tennant T5 Operator Manual 9002326 Rev. 08 (10-2015): tennantco.com
• Tennant T3/T3+ Operator Manual 9004144 Rev. 03 (04-2010): tennantco.com
• Tennant T260 Operator Manual TN7100042 Rev. 00 (04-2025): tennantco.com
• Tennant T16 Rider Scrubber Operator Manual 9008142 Rev. 00 (1-2011): thesweeper.com
• Tennant T1 Operator Manual 9003680 and T1 Battery Operator Manual 9008591 (07-2016): T1, T1 Battery
• Minuteman E14 Floor Scrubber User Manual 988760 Rev A (04/22): minutemanintl.com
• Clarke CA30 20B Instructions for Use, Form 56091130 (7/2014): caliberequipment.com
• Trusted Clean Dura 17 Auto Scrubber manual (04/2023): cleanfreak.com
• Kärcher BD 35/15 C Classic Bp operating instructions (11/23): kaercher-media.com
• Kärcher BD 50/50 C Bp Classic operating instructions (11/18): kaercher-media.com
• Trojan Battery, Deep-Cycle Battery Storage white paper (2012): ressupply.com
• Trojan Battery, Flooded Battery Quick Start Guide: ressupply.com
• Flux Power, C-Series C48 battery pack brochure: fluxpower.com
• Star brite, Antifreeze 101: starbrite.com
• KOST USA, DefendAL Marine and RV Antifreeze product sheet: kostusa.com