Steam Iron woes! Limescale constantly making clothes dirty Help?

[Starbear]

Just brought a Bosh new iron. Dh tried to iron last night and limescale brown muck made the shirt dirty. The iron is only 1 month old. Cleaning our last two irons didn't stop the brown spots. It says use tap water. I can't afford to buy bottles of ironing water. Has anyone got great tips?
Thank you in advance

Clean your iron with a descaler and from now on use filtered water, using a brita water filter or similar.

How about very cheap bulk 5L water form a pound-type/bargain shop.

A brita filter does not remove limescale afaik ...my parents only use brita water in their kettle and it still needs very regular de-scaling.

descaler doesn't do the trick very hard water around here. OR do you mean I have to do it every week or month. Another job on the to do list

Forgot to add, my local electrical shop always advises using bottled water with irons (we have very very hard water too)