How to clean the inside of an iron. The steam comes out rust colored.

https://www.realsimple.com/home-organizing/cleaning/laundry/clean-iron

I used to use a vinegar/water mix, pour into the iron and heat, then pour out and use plain water and heat again. I hve to admit that I do such little ironing I haven't done that in a while! See if that works. But, if the iron is rusting inside, you may need to replace.

The key to that is to drain the iron every time its used to prevent the water from forming rust when not in use.

Buy steam iron cleaner in the cleaning products aisle of the supermarket

Put some white vinegar into the water container, heat up and let steam onto a cloth until it runs clear. Empty out contents and refill with clean water, steam and empty again.

I used the instructions in the link, the baking soda /water paste worked great! https://www.realsimple.com/home-organizing/cleaning/laundry/clean-iron