Water Cooler Maintenance: How to Clean and Disinfect It

To clean a water cooler, unplug it, drain both taps and wash the drip tray and removable parts in mild soapy water. Disinfect the reservoir with a weak bleach solution, about 1/2 teaspoon per gallon, for at least 5 minutes, then flush clean water through both taps three times. Repeat every 3 months.

A water cooler looks spotless from the outside. The trouble lives in the parts you never see. The reservoir sits full of water around the clock, the drip tray stays damp, and every hand in the house or office touches the taps. Skip the routine and you get a flat or musty taste, slow flow, or a pink and gray film around the spigots. Always start with your owner’s manual, since ratios and drain points vary by model. Everything below comes from the manufacturers’ own cleaning instructions.

Water cooler maintenance schedule

Busy offices should lean toward the short end of every interval. A cooler shared by a whole floor sees far more hands and refills than one in a home kitchen.

Water cooler cleaning solution: bleach or vinegar?

Match the solution to the problem.

• Diluted bleach disinfects. Use it for routine sanitizing and anytime you see slime or mold. Use regular unscented household bleach, never splashless or scented.
• Distilled white vinegar dissolves white, chalky mineral scale and helps with flat or stale taste. It is not a registered disinfectant, so it does not replace the bleach step when there is growth.
• Mild dish soap handles the outside, the drip tray and removable parts. Oasis says to use only mild soap and water on the plastic cabinet and drip receptor and to keep bleach off them.

Never mix bleach and vinegar, and never run one right after the other without a full rinse in between. Together they release chlorine gas. Our guide to using bleach safely to disinfect covers storage and the other cleaners to keep it away from.

How to disinfect a water cooler with bleach

This works for most top-load and bottom-load bottled coolers. If your manual gives a different ratio or drain method, follow the manual.

1. Power down. Turn off the hot and cold switches and unplug the cooler.
2. Remove the bottle and drain. Run both taps into a bucket or pitcher until they stop. If there is a drain plug on the back, open it over a bucket. Water from the hot tank can scald, so go slowly and keep kids and pets away.
3. Wash removable parts. Take off the drip tray, the baffle and the bottle guard or probe if your model allows it. Wash them in warm water with mild dish soap and rinse.
4. Mix the sanitizer. The Oasis bottled cooler manual calls for 1/2 teaspoon of household bleach per gallon of water. Mix a fresh batch, enough to fill the reservoir.
5. Sanitize the parts. Submerge the removable parts in the solution for at least 5 minutes, then rinse them with clean water.
6. Sanitize the reservoir. Pour the solution into the reservoir, wipe the walls with a soft cloth, and let it stand 5 minutes. Then open the hot and cold taps so it runs through both lines.
7. Flush at least three times. Fill with clean water and drain through both taps. Repeat until there is no bleach smell or taste. Oasis calls for at least three flushes.
8. Reassemble and reload. Wipe the neck of a fresh bottle, load it, plug the cooler back in and switch the hot and cold tanks on.

How to clean a water dispenser with vinegar

Use this when the problem is scale or taste, not growth. Primo’s current water dispenser cleaning steps use vinegar this way.

1. Drain the dispenser. Switch off, unplug, remove the bottle and empty the reservoirs through both taps.
2. Mix the solution. Pour 2 cups of distilled white vinegar into an empty 5-gallon bottle with hot tap water.
3. Load and fill. Put the bottle on the dispenser, plug it in and let the solution fill the reservoirs. Primo says leave the cold switch off. The hot switch can stay on.
4. Wait 10 minutes. Then drain the reservoirs through the taps and the rear drain if your model has one.
5. Flush with clean hot water. Rinse the bottle, refill it with clean hot water, load it and run it through the taps and drain until the vinegar smell is gone.

If you descale coffee makers the same way, our Keurig descaling guide walks through the vinegar flush for that machine too.

How to clean a bottom-load water dispenser

Bottom-load units get the same bleach or vinegar routine, plus two spots that collect slime faster than anything else.

• The probe. This is the straw and cap that drop into the bottle. Wipe it with soapy water and a soft bottle brush, rinse, then sanitize it with the rest of the parts.
• The cabinet floor. Drips collect where the bottle sits. Wipe it with mild soapy water and dry it before loading a new bottle.

Some bottom-load models need the water line unclipped before cleaning, and some have a self-sanitizing cycle. Check the manual before you pull on tubing, since forcing a fitting can crack a seal.

How to clean a fridge water dispenser

1. Clean the nozzle. Scrub the spout and the dispenser paddle with a soft toothbrush dipped in warm soapy water. Skip abrasive pads, which scratch plastic and give grime a place to grip.
2. Wash the drip tray. Lift it out if it is removable, wash it, and dry it fully.
3. Change the filter on schedule. Whirlpool recommends a new filter every 6 months, or sooner if the indicator light comes on or the water turns cloudy or slow.
4. Flush after every filter change. Run 1 to 4 gallons through the dispenser, depending on the filter’s instructions, to clear air and carbon dust. Whirlpool suggests 5 seconds on, 5 seconds off until the flow is steady.

The ice side gets slimy too. Our guide to cleaning an ice maker covers the bin and the chute.

Signs your water dispenser needs cleaning now

• Musty, flat or plastic taste
• Pink, gray or black film around the taps or in the drip tray
• White, chalky buildup on the taps or in the reservoir
• Slow flow with a full bottle
• The cooler sat unused for a few weeks

Keeping office water coolers clean

In a workplace, the taps are a high-touch surface just like door handles and the fridge door. Wipe them daily, put the 3-month disinfecting date on a calendar, and make it one named person’s job so it never falls between teams. Our checklist for cleaning high-touch surfaces covers the other spots that need the same attention.

Frequently asked questions

If the cooler, the break room and the restrooms keep slipping down the list, Pro Housekeepers’ office cleaning services handle them on a regular schedule.