Thou Shalt Clean Thy Zojirushi Water Boiler

When I acquired my first Zojirushi I read somewhere that it might occasionally need cleaning. By the time I received my second Zojirushi water boiler a couple years later, I read it again.

Here we are yet a couple years later and they’re in need of cleaning again. Somewhere along the line I realized I never once wrote anything about cleaning either of the Zojirushi CV-DSC/CV-DYC water boiler units I happen to have.

So, here we go. Something you should always know how to do, and basic maintenance I tend to perform every six to eight months depending on water hardness and ph level.

Zojirushi Citric Acid (before mixing)

Using Citric Acid

While some people online have claimed success using baking soda and vinegar, that combination has a propensite for leaving odd smells in the unit. I highly recommend sticking to citric acid.

While I happen to buy the official Zojirushi Citric Acid cleaning packets on Amazon… you’re not obligated to do either. I’ve seen people use other brands of citric acid, and I’ve heard of still others who buy the stuff very cheaply by the pound to save money longer-term. Still, at only about $8 USD for four packets at the time of writing this, It’s a good deal to help your Zojirushi Water Boiler live longer and boil stronger.

Zojirushi Citric Acid (pre-mixed)

I use a small plastic container to mix the citric acid with how water before pouring it into the Zoji unit, but others have no problem pouring the citric acid directly into their Zoji. For what it’s worth, Zojirushi officially suggests pre-mixing.

This Zojirushi Needing Cleaning

Cleaning your Zojirushi Unit

The water boiler unit shown above was actually the cleaner of the two I own (yikes.) The other had been in a corporate office for an extended period and shared with dozens of others who used it as frequently as I did.

It may be difficult to see at first, but there’s a lot of calcification at the bottom of this unit and a little on the sides. This is only 6mo between cleanings.

I’ve seen some boilers (Zojirushi and others) with all kinds of stuff floating around inside because they’d never been cleaned. If this is the case with your unit… it may be tempting to just toss it and buy a new one. DO NOT do that. It’ll generally take only two or three cleaning cycles to cleanse the worst offenders! So for less than $10 you can definitely get yours up and running without nasty floaties!

Filling the Zojirushi After Adding Citric Acid Pre-Mix

These units are fairly simple to clean. Most Zojirushi units within the past decade or so have a cleaning mode built in which reboils several times to make sure everything inside breaks up properly.

To clean the unit normally, just pour in the citric acid pre-mixed, add water to the max fill line in your unit and let it boil as you normally would. You can activate the built-in cleaning mode of your Zojirushi water boiler by holding down the reboil button until the temperature indicator looks like it kinda bugged out.

A Shiny Clean Zojirushi Water Boiler

Tidying Up

Once the boil cycle is completed, or the cleaning cycle returns the temperature indicator back to a normal numeric reading you can empty your Zojirushi water boiler.

It is important however that you run all the cleaned water through the normal spout and not dump it from the top of the unit like abucket. Using the dispense mode allows the citric acid remaining to clean the tubing which leads to the dispenser spout. This will lead to cleaner tasting brews.

Also, while Zojirushi doesn’t officially recommend it, I also suggest running an extra boil cycle with fresh water in your now-clean water boiler in order to ensure everything is flushed out. Once again, running the entire vacuum empty of water using the dispense mode on the unit.

My Dual Zoji Setup

Conclusion – Enjoy Fresh, Clean Water Again

Now that your Zojirushi water boiler unit is completely clean, you can use it as you normally would, boiling up you water for tea, fresh pressed coffee, oatmeal, hot cocoa and anything else you need variable temperature water for.

Have at it!

35 thoughts on “Thou Shalt Clean Thy Zojirushi Water Boiler

  1. Thank you for these directions! I’ve own my Zoji for 6-7 years and did NOT know about the cleaning cycle. I would just boil it and let it sit for a while. I just followed your directions and it’s doing exactly what you described. Directions? Who knew? 🙂

  2. I have a Panasonic 2.2 water boiler. Do you know if I can I use the same instructions to clean my unit?

    1. Yes, you should be able to use the citric acid with any sort of kettle or boiler unit.

      Whether the Panasonic unit has a special “cleaning mode.” I’m not sure.

  3. Could you please tell me if it is super important to have the filter on because i have been given a Zoji and it does not have a filter?

    1. The small metal/mesh filter which attaches to the water outlet at the bottom of the unit is not essential to the unit’s operation. So no, it’s not “important”.

      However, the filter does prevent debris from entering the outflow tubing and getting stuck which can significantly hamper the flow of water from the unit, so it’s worth contacting Zojirushi and seeing what the replacement part would cost.

  4. Thank you so much for the instructions! The product/process worked great to clean out my Zoji 🙂 It looks brand new again!

  5. The letters inside the boiler in ours seem to be fragmenting and we can see small black particles float on the water. Anyone else has seen this?

    1. I have not seen this issue myself. I would recommend reaching out to Zojirushi support and verifying with them whether it is an issue with your unit, something with all units, or just a cleaning issue.

  6. I have followed your awesome directions – but this time for some reason it’s been 4 days already and it’s still on the wash cycle!? Has it ever taken you this long?? I’ve done this before and it’s never taken this long! Any advice? Thanks in advance!

    1. It sounds like your Zoji has probably gotten stuck in the cycle. The longest cycle I have had run is about 2 hours.

      You could probably unplug your Zoji for a minute and run the cycle again and expect the usual runtime.

      If you continue to have issues with the cleaning cycle, I recommend contacting Zojirushi support.

  7. I was recently given a 5-liter Zojirushi and just began using it yesterday. My husband and I would normally use about 1liter of water per day for tea. Is it necessary to toss and refill with fresh water every night or could we take a few days to run through the 5 liters? If it’s best to change water each day, could I simply fill it with only 2-3 liters? Thanks!

    1. You can also fill the Zoji part-way instead of a full fill.

      I recommend changing the water for fresh water every day, or two at most.

  8. We ran through the cleaning cycle on our Tiger kettle last night. It dispensed all of the citric acid solution just fine. We filled it up, reboiled fresh water, and now the dispenser won’t work. We enjoyed and ran the 8 hour longer cleaning option and still not working. I wish we never cleaned it. Thoughts?

    1. I am not familiar with the Tiger unit. I would recommend contacting the manufacturer.

      It’s certainly possible the unit simply got “stuck” in the cleaning mode and requires some kind of reset to return to normal operation.

  9. Found your excellent cleaning instructions when Google-searching, “How to remove H2O-boiler’s inner lid.” That’s because I STUPIDLY cleaned unit w/ VINEGAR (not using Cleaning Cycle, for i just learned of its existence from you.) Outcome: Inner Container’s calcification on bottom third is completely gone, altho’ it required 5 rinses to remove vinegar’s ODOR. Lid is another story — can’t get the ODOR out!!! (That’s the reason for my Google-search.) Inner lid’s silicone gasket reeks of the vinegar odor. No diminishing effect washing w/ dishwashing liquid. Now attempting w/ lemon juice. Forewarning: Don’t repeat my error of choosing vinegar (over Citric Acid) as the cleaning solution!!!

    1. This is why I do not use vinegar. Perhaps updating the post with notes on what to avoid would be helpful.

      I do not use vinegar or lemon juice. Only the citric acid. And it works very well.

  10. After my wife complain the bad smell of boiled water and found some little white pieces on the water, I open the lid. Guess what I found is the plastic part behind stainless steel cover is deteriorated and fall apart. Warn your reader to check the lid.

    1. A worthy note. I do think however that this depends on your frequency of cleaning using the citric acid. I’ve had no such issues over more than a decade of ownership.

  11. my bad that never really cleaned it (forgot how many years, might be 3-4 years). Suddenly one day the water had bad taste, hence I am doing the internet search. Any idea if I do not “officially” clean it, this is normal behavior? Before I find this post, I just water cleaned it and rested it for a day. When I restart, the water was fine and after 1 day I can feel the bad taste….—> curious to know if this is the expected behavior due to my bad or no maintenance?

  12. I don’t even bother with the cleaning cycle: I just mix the citric acid (about 2 1/2 Tbsp w 1 cup warm tap water), add to the empty Zojirushi boiler, and fill the rest of way (to the “max” line) with regular tap water. Then I just set it to boil – no cleaning cycle – and follow the rest of the instructions. This has always removed all the calcium deposits from my Zoji. (Note that this cleaning is only for the purpose of removing mineral deposits, and there is no need for extensive boiling unless your unit is heavily encrusted with minerals.)

    1. Your method is satisfactory. I followed the manufacturer instructions after discovering after some great time that cleaning was even required. Since the process was new to me, the care of the device was something I felt the manufacturer’s steps would be best to follow until I was more comfortable experimenting.

  13. I just cleaned my Zoji properly with the Citric Acid cleaner on
    March 1, 2018 and today April 18, 2018 it has some white
    powdery film on the insides and same sediments piled up
    near the wire filter in the bottom.

    Now I read that I can also activate the self-cleaning method
    of the Zoji by holding down the reboil buttom for awhile.

    will that activate without the Citric acid cleaner??

    1. It will. Though the white film is likely from the citric acid not fully dissolving. The cleaning mode should help there too. Just follow the cleaning instructions and you should be good to go!

    1. Zojirushi’s packets come with about 0.5oz (~15g) per cleaning packet.

      I would probably recommend around that amount. I don’t know if more would hard the device, but less may not get the job done.

  14. We bought our Zojirushi when our daughter was 6 months old for the endless supply of hit water we seemed to be in constant need of. It’s been a staple on the kitchen counter all year ever since. Our daughter is now a freshman in college and that Zojirushi is still going strong. Or is it? The water doesn’t taste the same… I confess to not cleaning it as often as I apparently should have over the years… what is the usual lifespan of these appliances?

    1. I have three, of varying ages. My first was purchased in 2006, and it has been running all day every day with periodic cleaning (after realizing it was needed). That’s 13 years of pretty much non-stop use!

      I don’t know if Zoji would recommend a top-end on the lifespan or not. But I will use mine until they die for sure!

  15. Hi, thanks for the great info! My Zojirushi just stopped distributing water. Instead it makes a strange noise when I press the button. Have you heard of this happening? Do you think cleaning it might fix this? I usually descale every ten days with a bit of vinegar in the bottom, but the water in my house is mineral heavy, so maybe the inside parts are blocked. Any thoughts?

    1. Zojirushi recommend using citric acid which believe it or not is cheaper than vinegar when bought in bulk.

      I don’t like using vinegar because I feel I can taste it in my tea for a while after using it to clean. But I don’t know if vinegar causes any harm to the device.

      Citric acid should dissolve most particulates stuck in the device though.

  16. I have issues with rust, the steel coated water heater coating has become pitted and the steel has rusted through the coating. We have been very diligent in cleaning the water heater in the prescribed manufacturers manner. But it has become corroded. Is this usual and is it safe to use the unit?

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