I used citric acid but see no improvements. It looks like my inner container is corroding.

In this case, mineral deposits built up over time have crystallized causing it to adhere to the coating. The crystallization only occurs during prolonged contact and can be avoided if the water heater is maintained regularly. When corrosion is apparent, please contact our customer support team for a service order request.

If you have not cleaned your water with citric acid since the initial purchase, please do so by following the instruction below. Some states may have higher mineral contents in water so the rate of how often the citric acid cleaning process must be repeated is about 1-3 months.

CITRIC ACID CLEANER INSTRUCTIONS
Please do not immerse your water heater in water or place it on a very wet sink.

1. Fill the inner container with cold/room temperature water to maximum level.
2. Add 1 packet of citric acid (1 oz. / 30g, into the water heater and mix lightly.)
3. Plug the power cord into the power source and choose the highest temperature setting.
4. After the water boils, the keep warm light will turn on. Please leave the unit for at least 8 hours or overnight. Please do not unplug the power cord during the cleaning process.
5. Dispense the water completely by using the dispense button or by pump.
6. Fill the inner container with cold/room temperature water to maximum level.
7. Plug the power cord into the power source and leave the product to boil.
8. When boiling is complete, the keep warm light will turn on. Please leave the unit on keep warm for at least 1 hour.
9. Dispense the water completely to remove the remaining citric acid.
10. Rinse the container with cold water.