It is limescale. Basically your steamer takes water and boils it dry and turns it to steam. Any minerals like calcium in your water is left behind as rocks or flakes.
It should be descaled once every couple of years. You can do it fast with a product like CLR, or overnight with white vinegar. Fill it up and leave it, next day, turn it on and get it hot, but not boiling. Turn it off and leave it to cool. Empty and rinse 3 or 4 times.
The measuring cup holds 1/4 cup. Fill with tap water and pour one full measure into the hole exposed by removal of handle. Then measure table salt into small hollow on handle. Next, pour two (2) full measures of salt into a second measuring cup full of water, and pour into Sisan. Never use more salt than will fill the measuring hollow in handle. Remember that should the steam cease, unplug and refill with two measures of tap water, but no more salt.
Maintenance:
Add one (1) teaspoon white vinegar to two measures of tap water, put it in the Sisan Steamer and let it run a few minutes. Then pour this out of the Steamer and rinse well to scale the inside.
https://www.google.com/search?q=Sisan+steamer+manual
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You will have to buy a new Shark Euro Pro Steamer because there are no longer any replacement parts for the current one that you have Shark had stopped making replacement parts for the one that you have too. . You could try on Kijiji and Craigslist. or the Market place on Facebook.
I don't have a manual but these are extremely simple to use once and there is a demo on youtube for business shirts How to use Elna Press for Ironing Shirt and other videos from same member show sheets and jeans. Technique is simple, place part of garment onto the board with the rest sitting on your knees (use press sitting down in front of it) to take the weight, lower press closed with your left hand, then bring the spring loaded right handle down to apply the pressure, this has a big spring behind it and applies pressure, wait 2-3 seconds then lift right handle to release the pressure and then using your left hand grip the whole press will want to open up again. That's it! Set the temperature setting on the press and iron from your lowest temperature items first, nylons, up to cottons, linens on the hottest setting last as it will take 5 minutes or so to come up to full temperature. If you have the vapojet spray attachement, then you fill this with tap water and slide it onto the handle, give it a spray with the press open before you close to press and it turns to steam. Cleaning the top hot plate can be done with a special cleaning stick product you can buy (or any similar iron cleaning stick will work too, but you need to apply it to a hot plate so be really careful as you do this, then wipe it off with some waste fabric. Great press to own and perfect for applying interfacing if you are a sewist, (just use a piece of waste fabric so side of the interfacing doesn't attach to the top plate or your bottom cover).
Not an answer, but a note to say this same thing has just happened with mine in Sydney. Its only three months old. I have contacted Deals Direct, and they don't have any repair options. They won't replace it becuase they model they have in stock is a newer one to the one I have, so a return seems to be the only option. Pity, because I loved this thing. It really made ironing easier.
