Remove algae from GV7070 water tank

Use white vinegar.

Use filter water when cleaning

Distilled water and filtered water are not the same. Distilled water is water that has been boiled then condensed so that most of the impurities that cause water hardness (Sodium, Calcium, etc.) have been removed. Filtering does not remove these which is why your iron will clog up much quicker. Same applies to your car battery, distilled water only! To clean it mix "Lime Away" with water about 1/4 cup with water every 6 months or so, then rinse with clean water a few times to get rid of the green color, steam until it comes out clear again..

Use CLR or any other lime scale remover you can find. Pour out any water in the bottom chamber and put some CLR into it. leave it for 10 minutes to an hour. Run it to have some CLR so though any passages, then pour out any remaining CLR and replace with water again to wash out the CLR. When you are satisfied that the CLR is all rinsed and replaced with clean water, then it is safe to iron again. CLR can alway be put on a cloth and wipe the iron surface or any deposits.

1) test the electronic control for defective and follow the next steps. God bless you
Clean an iron:

1. Unplug the iron and make sure it is cool before cleaning.
2. Use a toothpick or pipe cleaner to remove buildup in the steam vents, making sure the debris doesn't fall into the vents.
3. Use a fine sewing needle to carefully clean the spray nozzle of mineral deposits.
4. To flush sediment from a steam iron, pour 1/2 cup water and 1/2 cup vinegar into the water tank. Place the iron on a rack over a broiling pan and set the iron to steam until the tank runs dry. Repeat if necessary. Or follow the instructions for using a commercial iron cleaner.

Service the steam and spray mechanism:

1. Unplug the iron.
2. Use a fine sewing needle to unclog the steam valve assembly. Also, check the valve spring and replace it if it is broken or has lost tension.
3. If the spray pump is accessible, remove it and check for leaks by placing the spray tube in water and squirting the pump. Clean or replace as needed.

Clean a metal soleplate:

1. Unplug the iron.
2. Use a sponge and commercial soleplate cleaner or baking soda and water to remove dirt buildup on the soleplate. Rinse well with water and dry. Don't use harsh abrasives or immerse an electric iron in water.
3. Use very fine steel wool (0000) or an emery cloth to remove scratches and burns on the soleplate, then clean the soleplate.

see the next steps and fix it. God bless you
Clean an iron:

1. Unplug the iron and make sure it is cool before cleaning.
2. Use a toothpick or pipe cleaner to remove buildup in the steam vents, making sure the debris doesn't fall into the vents.
3. Use a fine sewing needle to carefully clean the spray nozzle of mineral deposits.
4. To flush sediment from a steam iron, pour 1/2 cup water and 1/2 cup vinegar into the water tank. Place the iron on a rack over a broiling pan and set the iron to steam until the tank runs dry. Repeat if necessary. Or follow the instructions for using a commercial iron cleaner.

Service the steam and spray mechanism:

1. Unplug the iron.
2. Use a fine sewing needle to unclog the steam valve assembly. Also, check the valve spring and replace it if it is broken or has lost tension.
3. If the spray pump is accessible, remove it and check for leaks by placing the spray tube in water and squirting the pump. Clean or replace as needed.

Clean a metal soleplate:

1. Unplug the iron.
2. Use a sponge and commercial soleplate cleaner or baking soda and water to remove dirt buildup on the soleplate. Rinse well with water and dry. Don't use harsh abrasives or immerse an electric iron in water.
3. Use very fine steel wool (0000) or an emery cloth to remove scratches and burns on the soleplate, then clean the soleplate.

I found the same happens with mine but only onthe lower temperatures

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Mix water with a little bleach shake it a bit then let it sit til green goes away, then rinse repeatedly until bleach smell goes away. empty water from iron when not in use.