Preserving experts - why won't my Kilner jar seal properly please?

[MaggieW]

I'm preserving lemons and have sterilised jars, boiled rubber seals, but when I put on the seal and close lid, it doesn't seal properly. I've tried several times so not sure where I'm going wrong. Can anyone help please?

Check the rings are placed the right way round, ie the lip facing outwards. Also you might find the seals may need replacing if they have been used before.

You know the seal has to be fitted on the lid don't you?

Agree seals only last one use.