how do descale an electric steam sterilizer

[sheepgomeep]

I've got an Avent bottle electric steam sterilizer that I havent used for 3 years. I'm due in 5 weeks and tonight I have decided to get it down and clean it.

I've looked in the bottom and it badly needs descaling but I don't know what I can use. The sterilizer did come with the sachets of powder but I've used all those previously.

It says on the front to descale with citric acid but where and how can I obtain this.

Any ideas?? Thanks

Mothercare or Boots will sell a steriliser descaler.
Our local ones have them at any rate. If not, ask at a pharmacy for citric acid.

I have an Avent one too, the instruction book said at the time to use a solution of white vinegar and water (half and half) and leave it to soak. It smells a bit though, but it works, I did read on here that you can put water and bicarbonate of soda in afterwards to get rid of the smell.

I?ve looked for steriliser descaler but I can never find any.