Steam Iron leaving brown marks as it irons...

[saffrone]

Hi
I have had a philips steam generator iron, which is great, but has rescently started to produce brown steam leaving marks which need to be rewashed out...any ideas on what's going wrong/how to solve it? Manual says not to descale; we have been using deionised water.
Thanks for any advice.

Mine does this when it's not quite up to temperature.

AAAAh! Enlightenment! Thank you; thought I was being careful about leaving it prescribed 8 minutes, but will try waiting a little longer before starting ironing.

If it's happening to the first couple of items then it's definitely because it's too cool to produce enough steam so spurts out icky water instead.

My iron does that too when it's not very hot. V. annoying!!