glass filled with water from a cooler

How to Clean a Water Cooler Properly

Any type of water dispenser needs regular cleaning to preserve the fresh taste and cleanliness of the water.

Most people don’t think of it as a part of their chore routine, but water coolers need to be cleaned a few times a year to keep them in optimal working order. You can use the tips in this walkthrough to clean just about any water vessel, from smaller water filter pitchers to the big water cooler at work. Follow the steps and remember the safety tips to make sure the water cooler isn’t damaged and no cleaning products leach into the water. 

Do Water Coolers Get Dirty?

In public spaces like offices or schools, water coolers can get pretty grimy from the sheer number of people who use them. Fingerprints and possible spills in the drip tray leave marks that should be cleared away from time to time. Besides these incidental marks, water itself can leave behind built-up minerals. Sometimes the environment surrounding the water cooler encourages the growth of bacteria over long periods.

This is particularly common in warm places with little natural light. Testing your water for contaminants and unwanted additives is healthier and leads to better-tasting water. You can also ensure your water cooler stays cleaner for a longer time if you do this regularly, although you should still clean the water cooler periodically even when the water inside it is perfectly clean.

If you have a water cooler with removable tanks, pay special attention to the places that have direct contact with the tank. That’s a great place for spills during tank installation and built-up minerals from the water over time.

Calcium deposits on faucet

Minerals in water can cause limescale around a water cooler’s spigot and drip tray (just like they do with taps and household appliances like kettles).

Common Causes of Water Cooler Build Up

Bacteria are fairly rare in water coolers that are properly maintained. More frequently, minerals in the drinking water build up over time and cause grime around the spigots and drip tray. Even if you treat your drinking water to remove particles and unwanted additives, some will inevitably remain. They’re harmless and even healthy in most cases, but they can leave white build-up. Plus, water makes a great environment for things to grow if they’re left to their own devices. 

Touching the spigot of the water cooler allows bacteria on people’s hands to transfer to the spigot and enter water bottles as they’re being filled. Cleaning products can also leave behind chemicals in high enough amounts to taint the water with a chlorine taste.

Safety Considerations for Cleaning Water Coolers

Whatever your specific water cooler and choice of cleaning methods, make sure to remember the following safety tips each time you clean the device. 

1. Unplug the machine: Water coolers use electricity to maintain the temperature of the water. Hot water spigots also rely on electricity to work. Avoid possible injury by unplugging the machine before you get started. Cleaning products and water can cause shocks or damage to the interior electrics of the water cooler. The best time to do this for both top-loading and bottom-loading water coolers is when you’re changing the tank.

2. Let the hot water faucet Cool: Accidentally touching the hot water spigot before it cools down can cause a pesky little burn or even worse. Paper towels and rubber gloves might not be enough to prevent your skin from getting a burn. Unplug the power cord from the electrical outlet well in advance of your cleaning to make sure the hot water spigot has plenty of time to cool. 

3. Be careful with chemicals: Ventilation and plenty of room are vital to prevent light-headedness, especially if you’re using chlorine bleach or other powerful disinfecting solutions. Avoid touching your eyes and mouth and wear clean rubber gloves that you can rinse or dispose of after the job is done. If you’re making a bleach solution or mixing baking soda to make a disinfecting agent, make sure you have the proper measurements and know how to dispose of the remaining water/chlorine solution when you’re finished. 

4. Use the right tools: In addition to clean rubber gloves, find cleaning equipment that won’t leave any remnants behind. The cost of simple tools like lint-free towels or scrub brushes may baffle you at first, but it’s worth it to have quality items that won’t leave things behind and possibly taint the drinking water. 

Water Cooler Cleaning Checklist

You may not need all of these things for some smaller water coolers, but some items are essential for getting a water cooler completely clean. 

  1. Scrub Brush
  2. Clean Rubber Gloves
  3. Lint-Free Towel
  4. Sanitizing Solution
  5. Face Mask for Fumes
  6. Fresh Water for Rinsing

It’s a fairly minimal list of requirements, but these few comparatively inexpensive items can save you lots of money in maintenance costs. 

Water Cooler Cleaning Solution Recipe With Bleach

Even unscented bleach can cause skin damage with enough exposure. Dilute it with a gallon of water and it will be strong enough to clean the water cooler but present less risk of skin damage. Of course, ingesting any of this chlorine solution will still be harmful even when it is diluted with a gallon of water. For sanitizing purposes, one gallon of water and about a tablespoon of unscented chlorine bleach should do. If you find that it isn’t quite getting the job done, add another tablespoon of bleach. 

Water Cooler Cleaning Solution Recipe Without Bleach

If you prefer not to deal with strong chemicals like chlorine bleach, you can substitute white vinegar instead. This vinegar solution will still have a strong smell, but it’s not dangerous to the skin and won’t stain your clothes or harm you if you ingest some accidentally. Combine ¾ of a gallon of water with ¼ a gallon of white vinegar to make the solution. That is 1 quart of white vinegar to 3 quarts of warm water. Stir everything to make sure the vinegar is evenly distributed in the disinfecting solution.

Can I Clean With Tap Water?

If your goal is to remove grime and built-up minerals, using fresh filtered water is going to be your best bet. Hopefully, you already have a great water filter that churns out clean water readily from a standard tap. Planning can help here. If your water cooler already produces fresh drinking water that’s effectively filtered, you can drain the remaining portion of the tank when you’re installing the next tank and use that water to clean the cooler. 

tap water

How to Clean Top-Loading Cold Water Coolers

On a top-loading water cooler, the tank is turned upside down so the spout goes inside the machine and feeds the spigots. Cleaning them is fairly straightforward. Make sure you have the supplies we listed earlier in this guide and the cooler has been unplugged and then follow these steps:

1. Make sure the old water tank is empty: When you take the tank off the top of the cooler, the remnants may spill out. To avoid wasting water, drain the rest of it out and use it in your sanitizing solution.

2. Remove the old water tank: On most top-loading water coolers, all you need to do is pull the tank up and remove it from the connecting point. It might take a little bit of elbow grease, but not too much. 

3. Inspect the old tank for build-up: See whether grime or minerals are caked onto any part of the old tank. Also, take a look inside the reservoir to make sure there’s no build-up there either. 

4. Remove water guards & drip trays: We want to make sure this entire water cooler is completely clean, so remove any accessories such as drip trays and clean them separately. The water guard may be inside the reservoir – it’s the part that punctures the tank during installation on some top-loading water coolers.

5. Dry the water cooler: Any existing water that’s left behind inside the reservoir or on the water cooler itself needs to be dry for the cleaning solution to be as effective as possible. Use a clean cloth to remove this water. 

6. Disinfect the water cooler: Use a clean, lint-free cloth that’s been dipped inside your sanitizing water solution. It doesn’t have to be drenched, just damp. Don’t ignore the back of the cooler, either, but be mindful of any electronics back there. 

7. Clean inside the reservoir: Continue with the disinfectant inside the reservoir, making sure to get in all the nooks and crannies. Pay particular attention to the connecting points between the tank and the cooler, especially the water guard. 

8. Rinse the water cooler: Use fresh filtered cold tap water to lightly go over the water cooler and make sure none of your sanitizing agent is left on the surface. Repeat the action inside the reservoir. 

9. Let everything dry: If possible, set the water cooler in sunlight in a well-ventilated part of the room near a window or door so it can dry completely. Everything will stay cleaner longer if there’s no water collected inside it. 

10. Clean the accessories: Don’t forget to give the drip tray and spigots a good cleaning. Rinse them and let them dry just like you did with the rest of the water cooler. 

11. Reassemble the water cooler: Put everything back in its place, add a new water bottle on top, and then plug the power cord back in and you have a clean cooler that should stay that way for months to come. 

How to Clean a Bottom-Loading Cold Water Cooler

On machines where the water tank is loaded from the front and sits on the ground, cleaning is a bit easier. While maneuvering around the inside of the reservoir is a bit awkward with top-loading cold water coolers, you can see what you’re doing better on a bottom-loading one.

The steps for the cooler are essentially the same. You need to unplug the cooler well in advance to make sure the hot water spigot won’t burn you. Then you remove the accessories, dry everything, apply the disinfecting solution, rinse it, and let everything dry.

Cleaning the Water Channels in a Cold Water Cooler

For the water to make its way from the tank to the spigot, small tubes or other channels must be in place. So, how can you clean these pesky channels without causing damage to the water cooler? It’s easier than it sounds. For top-loading cold water coolers only, you can use your disinfecting solution. Pour it into the reservoir and let it sit there for about 15 minutes to remove any build-up. Then simply pump it through the water cooler to remove it. 

Rinse the cooler thoroughly with cold water to make sure there is no remaining vinegar or chlorine taste left behind. Remember that these channels should be dry after the cleaning as well, so leave the cooler out to dry for a bit longer than you think it needs.

Cleaning Hot Water Coolers

When you clean inside the reservoir and rinse the channels in a hot water cooler, you can’t use chlorine bleach. White vinegar may not cause problems, but it’s not the best option either. Instead, boil water and pour it into the hot water system to clean it.

Let the boiling water sit inside the system for a few minutes and then scrub the inside with a scrub brush. Drain the water and let everything dry out and you’re all finished. Make sure you also use food-grade cleaning materials and not industrial ones. The hot water system is a bit more sensitive and any leftover debris will decrease the quality of your water and potentially lead to malfunctions or fire hazards.

Blue water gallon on water cooler in office

Making sure you use clean water bottles will go a long way towards a clean cooler.

Keeping a Clean Water Cooler Clean

Once you’ve cleaned the water cooler, you’ll probably want to keep it that way for as long as possible. This is a challenging task around the office or a house full of people. But there are some things you can do to keep the water cooler well-maintained and your drinking water clean. 

  • Use clean water bottles: Recycling water bottles is a great idea, but returning to the water cooler with a dirty bottle can spread bacteria from people’s mouths. People aren’t always aware of what they have on their bottles and it only takes a quick rinse to avoid the worst consequences. Reusable water bottles are the best initiative for this. Plastic water bottles damage more easily and are a bit more challenging to clean if they lose their shape. 
  • Invest in the right water filter: The most common causes of build-up on water coolers come from minerals in the water itself. As such, filtering your water can reduce build-up. It also makes the water healthier and better-tasting, too. A reverse osmosis filter, for example, will remove contaminants and additives that can cause build-up. It won’t completely erase the need for regular cleaning, but it will greatly lower the grime that is in there when you do clean the water cooler.
  • Clean spills: Changing the water tank on any cooler can lead to spills. Make sure these aren’t left to dry on their own, as it could cause build-up to form more quickly. Also, take care to keep the drip trays and spigots clear of spills and moisture as much as possible. 
  • Avoid contact with the spigot: Spreading bacteria happens because people touch the spigot with unwashed hands or dirty water bottles. As much as is feasible, try to keep from touching the spigot. Regular wipedowns and spigot cleanings will also help the whole operation stay clean and make your drinking water that much cleaner. 
  • Change the tank regularly: Sealed and properly stored water has little chance of spoiling before you get to it, especially in offices and households with lots of people in them. However, if the water is opened and left sitting for too long, things can begin to grow inside. For an extreme example, algae can grow with nothing but water and light. It takes lots of time and people will definitely start to notice, but smaller molecules can also begin to form. Plus, old water has more opportunities to take on contaminants that will change its taste and possibly its health value. 


Water coolers are a great way to keep fresh drinking water on hand so that large groups of people can access it. However, as more people go to the spigot and refill their water bottles, grime can build up. Nobody wants to see build-up around their water cooler. You can use the tips in this guide to clean your water cooler whether it’s top-loading or bottom-loading. Use white vinegar in place of chlorine bleach in cold water coolers and boiling water in hot water cooler systems. 

It may seem like a long process, but keeping a clean water cooler is a straightforward process that you can complete in well under an hour. Maintaining that level of cleanliness might be trickier, but you can still reasonably expect to go for about six months of use before you need to clean your cooler again. 

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Joshua Perkins

Joshua spent ten years as a water systems technician in California before settling down with his wife and two young children in Nashville in 2018. Through all of his experience, he learned the benefits and shortfalls of so many different types of water filtration systems, from pitchers to whole-house installations. He started Water Filter Authority in 2019 to empower other families to make the right decision for their long-term health and wellness.