How to Clean a Zojirushi Water Boiler
Zojirushi water boilers are highly durable, but over time, minerals from tap water will build up on the inner container, leaving white scale deposits or dark spots. This mineral buildup can make the boiler noisy, reduce heating efficiency, and affect the taste of your water. This guide covers how to safely descale your Zojirushi boiler using the manufacturer-recommended citric acid method.
What You Will Need:
- 100% Food-Grade Citric Acid (about 30 grams, or 2 tablespoons)
- Fresh, clean water
- A small cup (for mixing)
- A soft, non-abrasive sponge or micro-fiber cloth
- Paper towels
Step-by-Step Instructions
Step 1: Dissolve the Citric Acid
Do not pour dry citric acid directly into the water boiler. Instead, place 30 grams (about 2 tablespoons) of food-grade citric acid into a small cup of warm water. Stir the mixture thoroughly until the citric acid crystals are completely dissolved.
Step 2: Fill the Boiler with Water
Pour the dissolved citric acid mixture into the Zojirushi inner container. Next, add cold tap water to the boiler, filling it all the way up to the "Max" fill line indicated on the inner lining. Close the lid securely.
Step 3: Initiate the Automated Cleaning Cycle
Plug in the boiler. Most Zojirushi models have a built-in cleaning cycle. To activate it, press and hold the "Reboil" (or "Keep Warm") button for more than 3 seconds. The temperature display lights will begin to flash or rotate, indicating that the automated hot descaling cycle has started. This cycle typically takes 1.5 to 2 hours.
Step 4: Drain the Hot Water Safely
Once the cleaning cycle completes, the display lights will stop flashing. Unplug the power cord and remove the lid completely. Carefully pour out the hot water through the designated "drain" side of the container. Note: Do not spill water onto the control panel, power receptacle, or exterior body of the boiler.
Step 5: Rinse and Flush the Internal Pipes
To remove any lingering citric acid from the internal pipes, fill the boiler with plain cold water. Plug the unit back in, bring the water to a boil, and dispense about 1 to 2 cups of water through the spout. Unplug the unit, let the remaining water cool, and pour it out. Your boiler is now descaled and ready for normal use.
Frequently Asked Questions & Troubleshooting
How often should I descale my Zojirushi water boiler?
As a general rule, you should clean your water boiler every 1 to 3 months. If you live in an area with hard water (high mineral content), you may need to clean it more frequently—as soon as you notice white flakes floating in the water or rough buildup on the inner container.
Can I use vinegar to clean my Zojirushi boiler?
No, you should not use vinegar. Vinegar contains acetic acid, which can damage the delicate non-stick fluorine coating inside the Zojirushi inner container. Additionally, vinegar leaves behind a strong, stubborn odor that is extremely difficult to flush out of the internal pipes.
What are the white flakes floating in my hot water?
The white flakes are calcium carbonate. They are harmless, naturally occurring minerals found in tap water that precipitate out and harden when water is boiled continuously. They are not plastic or non-stick coating peeling off, but they do indicate that your boiler needs to be descaled immediately.
How do I clean the exterior of my Zojirushi water boiler?
Simply wipe the exterior body and lid with a soft cloth slightly dampened with warm water. Never submerge the entire boiler in water, and avoid using harsh chemicals, steel wool, or abrasive cleansers, as these will scratch the surface and ruin the control panel.