The Leicester Cloth Nappy Library has a set of instructions for washing that is part of the hire agreement for anyone hiring the nappies.
By borrowing from LCNL, you agree to wash according to our guidelines to ensure the hire kits remain well looked after.
Newborns and exclusively breastfed babies
All poo is water soluble prior to weaning so can go straight in your washing machine
Remove nappy and store in large wet bag being sure to secure Velcro tabs to prevent snagging on other items in the wash
We recommend you wash delicate items such as wraps inside the mesh laundry bag
When it is wash day tip/empty the nappy bag into the machine and put the bag in with it
We recommend you wash no less frequently than every three days
Fill your machine two thirds full (bulk out with wipes or anything else you like if needs be) and wash for no less than half an hour on a cool rinse and spin wash (30 degree) wash. No need to add detergent.
Then wash with non-bio laundry powder for at least two hours on a 60-degree wash. If there are bubbles still visible after the wash is done you will need to do another rinse cycle.
Never add fabric softener as it significantly damages the nappies
Remove from the machine and line dry, ensuring all inserts have been agitated out during the wash
Never put waterproof nappies in the tumble drier (ones with PUL shells)
You can tumble dry inserts, wipes, boosters, liners and fitted nappies (ones that need a wrap over the top) on a low heat, though this is not encouraged
Do not worry if the nappy insides feel a little stiff, they will go soft when warmed by baby and when they encounter any liquids
Never dry PUL nappy shells on heated items like radiators or heated dryers as it can melt the plastic cover
After some practice you will learn which ones dry quickly and which ones can take longer
Babies on Solids or Formula
As above, except that as much poo as possible is removed from the nappy or liner prior to storing in the wet bag/washing.
And in handy printable image form (right click and "view image" for full resolution):