Zojirushi Water Boiler: Complete Troubleshooting Guide


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If you have the magical Zojirushi water boiler in your home or office, you know the feeling of fulfillment at finding your hot water ready when you need it for a cup of tea, soup, or your morning oatmeal. But, what if your Zojirushi water boiler suddenly has issues?

Your Zojirushi boiler may present issues such as failing to turn on or stop boiling, not pumping water, giving water with bad taste, rusting, or showing E3 and E4 errors, among others.

You can call for service if your Zojirushi water boiler has issues you don’t know how to resolve. But you can easily fix most of these common issues by troubleshooting your boiler, which is why we have put together this comprehensive troubleshooting guide for you. Read on for the fine points.

Zojirushi Water Boiler Not Turning On

If your Zojirushi water boiler doesn’t turn on, you should suspect one of these power issues:

  • The power plug is not connected to an electrical outlet.
  • The outlet is faulty.
  • The boiler’s cord or the heating element is damaged.

How to Fix

Check to confirm that the power plug is connected. If it is, follow these steps to check for other issues. 

  1. Turn the boiler off from the electrical outlet and unplug.
  2. Plug the boiler into a different outlet and try running it (If it turns on, the previous outlet is faulty. If not, the boilers cord or heating element is damaged.
  3. Plug a different appliance into the same outlet to confirm it works. If it does, your boiler has a power issue, and you should seek professional service.

Zojirushi Water Boiler Won’t Stop Boiling

If your Zojirushi boiler won’t stop boiling after the expected time has elapsed (33min for 3L and 42min for 4L), your boiler’s temperature regulating device (thermostat) has probably malfunctioned.

How to Fix

Do a one-time-trial disconnecting and letting it rest for a while before connecting again and testing to see if it stops boiling when it should.

If the problem is not resolved, contact the Zojirushi Customer Service or call the store where the boiler was purchased.

Zojirushi Water Boiler White Particles

After using your Zojirushi boiler for a while, calcium and other water minerals will build. This is called ‘scale’ and is responsible for the white particles you see on your boiler’s inner surface and filter. Though not harmful to your health, the scale can tamper with the water boiling process.

How to Fix

Perform the citric acid cleaning to descale your boiler using these steps: 

  1. Pour a packet of Zojirushi Citric Acid Cleaner CD-K03EJU into a cup of warm water and stir to dissolve.
  2. Pour the solution into the boiler and fill it with water to the Max line.
  3. Close the outer lid and connect the plug. Then press and hold the REBOIL button for about 3 seconds to activate the descaling/cleaning mode.
  4. Wait for the cleaning process to complete (around 1.5 hours). The LCD lights will blink throughout the cleaning process and stop blinking and stay on when it’s done.
  5. Unplug the boiler, detach the boiler’s lid and dispose of the water. 
  6. Fill the boiler and REBOILER to remove the smell of citric acid, then dispose of the water again. Your boiler will be super clean!

Zojirushi Water Boiler Not Pumping

There are several issues that can cause your Zojirushi boiler not to dispense water:

  • The plug is not connected.
  • The boiler is full of air bubbles from boiling.
  • Scale/residue has accumulated in the boiler.
  • The automatic dispense lock is engaged. 
  • The water route is blocked by calcium.

How to Fix

Perform the following to resolve each of the issues:

  1. Plug not connected – connect the plug.
  2. Boiler is full of air bubbles – carefully open the lid to release bubbles.
  3. Scale has accumulated – perform the citric acid cleaning explained in the previous section.
  4. Automatic dispense lock is engaged – press UNLOCK then DISPENSE.
  5. Water route is blocked – perform the citric acid cleaning.

Zojirushi Water Boiler E4 Error

The Zojirushi manual indicates an E4 error as a system malfunction.

How to Fix

The manual directs the user to contact the store where the product was purchased or call the Zojirushi Customer Service.

Zojirushi Water Boiler E3 Error

The Zojirushi manual indicates an E3 error as a system malfunction.

How to Fix

The manual directs the user to contact the store where the product was purchased or call the Zojirushi Customer Service.

Zojirushi Water Boiler Rusting

If your Zojirushi water boiler has rust spots on the surface of the inner container, the container has come into contact with iron deposits from the water. 

How to Fix

Perform the citric acid cleaning explained earlier. You can consider using vinegar in place of the citric acid if you do not have it.

Zojirushi Water Boiler Peeling

Peeling in your Zojirushi water boiler may be indicative of scaling or of wear. If you notice that the non-stick coating of the inner container is peeling, this is most likely an indication of wear from consistent boiling. If, instead, your boiler shows flakes of limestone, it has accumulated plenty of calcium from the water.

How to Fix

If your boiler is peeling from wear after years of use, consider replacing it. If it is still new, it could have a defect, and you should contact the store where you bought it or contact the Zojirushi Customer Service. 

Suppose your boiler has flakes from scaling. Perform the citric acid cleaning.

Zojirushi Water Boiler Not Heating

When you’ve just filled your Zojirushi water boiler, and it is not heating, there are two possible issues: the power plug is not connected, or the outer lid is not closed.

Instead, if your boiler is in the keep warm mode and you’ve added more water, your boiler may not be heating because you have not hit the REBOIL button.

How to Fix

If the plug is not connected, simply connect the power plug. 

If the outer lid is not closed, push it down to close.

If you’ve added water to your boiler while keeping warm mode, press the REBOIL button to get it running.

Zojirushi Water Boiler Bad Taste

Bad tasting water from your Zojirushi boiler signifies that the water inside is dirty with scale or other residues (if you are sure the bad taste is not from the water you poured in). 

From customer reviews, it seems bad taste could also come from damaged boiler parts that need occasional replacement, such as the inner lid gasket.

How to Fix

Ensure you run the citric acid cleaning every 1-3 months to avoid calcium accumulation and other forms of dirt. That will also prevent your boiler parts from calcifying and getting damaged, causing bad taste.

Replace damaged parts. You can order them from the Zojirushi Parts & Accessories web page or call their customer service during working hours. Note that you’ll need to have your boiler’s model number to make the order.

Zojirushi Water Boiler Bad Odor

If the water from your boiler has a bad odor, there are three possible issues:

  • Your boiler may have accumulated scale or other residues in the inner container.
  • You’ve not done the citric acid cleaning for more than the recommended 1-3 months.
  • You’ve not used your boiler for a long time. 

Note that a new boiler may smell plastic for the first few boils, but that disappears with time. Also, you may smell the chlorine from tap water.

How to Fix

If the smell is from residue or scale or missed boiler cleaning, perform the citric acid cleaning.

If you have not used the boiler for a long time, discard the water after the first boil and boil water for consumption after that.

Zojirushi Water Boiler ‘HH’ Error

Suppose your Zojirushi water boiler has a beeping sound with a light on and an ‘HH’ error. In that case, the boiler is low on water, or the automatic shut-off function has been activated by pouring water that was already hot into the boiler.

How to Fix

Follow these steps to fix:

  1. Unplug the boiler.
  2. Allow the inner container to cool down.
  3. Fill the boiler to the required level.
  4. Plug the boiler.

Zojirushi Water Boiler Has Humidity on the Display Window

Moisture on your Zojirushi boiler display window is a sign of wrong boiler handling: you have filled the boiler directly from the faucet or have placed it inside a wet sink, causing moisture to sip into the main body.

How to Fix

Stop using the boiler until it is dry again. Moisture in the boiler’s main body can cause electric shock or a short circuit.

Final Thoughts

The Zojirushi water boiler is an excellent addition to your kitchen appliance set. The boiler will not only save you multiple boils with a standard electric kettle, but it will give you all the hot water you need for your teas and soup for an entire day without worrying about boiling and reboiling.

As such, an issue with your boiler will disrupt this comfort, which is why knowing how to troubleshoot the problems with your Zojirushi boiler is crucial.

Remember, however, that you should only troubleshoot simple problems that will not pose a risk to you or ruin your boiler. Leave the complex issues to the authorized Zojirushi Service Center near you.

Jake Alexander

Jake is a freelance writer from Pennsylvania who enjoys writing about science and sports. When he's not writing for Temperature Master, he can be found watching the NFL or playing basketball with his friends.

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