Its generally recommended that you do a cold wash without detergent, hot wash with detergent, topped off with a final cold rinse. The first wash is to remove the poops. So, you wash on cold so as not to bake the poops in. The second wash is the cleaning/sanitation cycle. The final rinse is to really remove any remaining detergent (or other stuff). I've actually just started doing yet another cold rinse due to some stink issues. So far so good. Not happy about all the water I'm using though.
I also never wash with hot, maybe my nappies once a month or less ( I will be strip washing in the next couple of weeks because my MUm has been washing nappies and she doesn't use anything cloth friendly, she used to used terry flats which handle all abuse) so all my washes and rinses are on cold.
Well before all this moving, I did a cold rinse, hot wash, extra cold rinse. For the most part, zero issues.
~Jackie, mommy to Aiden (11/2/10) and Zoe (VBAC 11/27/12)