How to clean (Sanitize) a water cooler.

(note this instruction sheet also has a descale step for those coolers with a hot water dispenser)

Water coolers were an incredible invention! The benefit of having clean water available is often taken for granted and the water cooler is seldom kept in the best shape when it comes to cleaning it. We just keep adding the bottles and after the glug-glug the water is ready!

Although, at The good Water Guys we prefers to eliminate those little darlings by replacing them with Bottle-less units, we still understand that the bottled cooler has its place on planet earth!

 Reasons for Cleaning:

CROSS-CONTAMINATION – elimination and protection is the most neglected part of the cooler.

The bottle just by handling it creates a potential for contamination two times. When it is delivered and then when it is put onto or into the cooler. Any time that the bottle is handled by a hand it can be contaminated.

When the bottle water starts to flow into the cooler and you her that glug-glug it is sucking in air and anything in the environment is sucked in with it! Imagine if someone has not been feeling well and has been coughing or sneezing in the area when the bottle water is being changed!

Those little devils called bacteria and or germs will breed until the cooler is sanitized!

So if you have not cleaned your unit you just never know! I have seen units that are just amazingly dirty in the water bowl or reservoir.

TASTE AND SMELL Sometimes the taste of the cooler is just not ideal. Those tastes can be coming from the growth in the reservoir.

PEACE OF MIND – The majority of people who do the bottled water coolers do it for the flavor and the smell. A clean water cooler will restore your Peace of Mind!

 Things needed to clean your Water Cooler:

 Although it takes only about 30 minutes to clean a water cooler the first attempt may take a bit longer. So plan a time when you can take up to 1hr. If you have a hot water dispenser and you want to remove the harness scale from hard water you can add another 10 to 20 minutes.

  • Clean Rubber Gloves
  • Paper Towels or New Micro-Fiber cloth or lint free rag.
  • A Clean Container and Bucket that can hold a gallon or two of water.
  • A new clean sprayer bottle.
  • A small cork or plug if you have a Hot & Cold cooler.
  • A small amount of pure unscented household bleach.
  • One gallon of pure vinegar.

 The best time to clean the cooler is when the water bottle is about empty or empty.

 Cleaning Process

  • Disconnect the unit from the electrical outlet.
  • Remove the bottle from the cooler.
  • Drain the cold water from the cooler (blue faucet) until empty. This water is good water…. Give it to your pet or water your plants. If you notice any ice in the bottom of the reservoir you can let it melt or add some hot water to help it. Drain that again. Then do the same to the hot water, being careful not to burn yourself.
  • On the top of the cooler there is a water guard or spill-free top. That needs to be removed. It is either a twist top or a pressure fit. Some observation will give up the answer to the removal.
  • Once you have the spill plate off you need to remove the baffle inside the reservoir as well this is usually a while plastic or stainless steel plate/ tube assembly that lifts straight out. If there is no baffle don’t worry about it.  
  • Once you have removed the baffle you should see two holes at the bottom of the reservoir leading to the 2 faucets. In a HOT and COLD unit the reservoir has the center hole leading to the heating chamber. This one is the one that you need to plug. Failure to plug this one can lead to some nasty tasting hot water after you clean the unit especially if you are using a chlorine cleaning solution. If you intend to clean the hot water chamber you can also use some vinegar to help in the descaling of the hot water chamber. This requires a bit more soaking and a bit more drain and flush see step 8. YOU DECIDE!
  • The cleaning or sanitizing solution mixing goes like this. You need about 1 table spoon of pure unscented bleach to 1 gallon of water. That ratio is MORE THAN PLENTY! You can put some of this solution in a clean new spray bottle. The tendency is to add more chlorine but it can make it difficult to flush the taste later.

Hot Water Chamber Descaling Step

  • If you are going to descale the heating chamber you will need about 3 or 4 cups of vinegar to fill the heating chamber reservoir, add clean cold tap water until it is full or getting a bit water on the top where the water is no longer going down. You need to let this sit for about 10 to 15 minutes to allow the vinegar to loosen the hardness scale and then drain it through the red hot water valve, you may notice small white chunks of the hardness coming out of the faucet when you are draining it. Do it again letting it sit again for another 10 to 15 minutes then flush it with clean tap water or better yet some bottled water from a fresh bottle? You may need to flush more than once to remove the vinegar smell. Now cover the hot water supply hole in the center of the reservoir to continue with the reservoir sanitizing.


  • The hot portion of the cooler is usually sanitary because it gets pretty hot. That is also what causes the scale to stick to the chamber. Like a coffee pot. Vinegar will clean it. If your home has a softener in good working order this step can be skipped as no scale should exist!
  • Spray some of the chlorine water mix around the reservoir. You should have your gloves on. Dip the clean lint free rag lightly if you feel you need to but with a good sprayer you can now just wipe the reservoir. Next clean the baffle and spill free top, again spraying with the solution and wiping with the rag. After wiping the reservoir add the balance of the chlorine mixed water and let it set for at least 5 minutes to insure enough contact time of the chlorine with anything in the reservoir.
  • Now it is time to do a good flush of the sanitizing solution. Fill to the top the reservoir of fresh bottled water and then completely drain the unit through the Blue cold water faucet. Refill with bottled water to the top again. Then drain again through the cold water side. Remove the hot water cork and fill one last time to the top. Flush first ½ of the reservoir though the hot side and the rest through the cold side. 
  • Time to replace the baffle and spill free top. (make sure you still have your gloves on.)
  • Replace or put back a fresh bottle water jug and drain a couple of glasses from each side.
  • Taste the water… if you have any noticeable chlorine or vinegar taste flush a couple more glasses unit the water tastes clean again.
  • Reconnect your unit to the electrical outlet. Keep in mind that it may take a few minutes for the hot water to get hot but you are done!