Yes. A criminal record is for life. Although most offences become 'spent' after a certain period of time (and so don't have to be declared when applying for employment which is not exempted from the provisions of the Rehabilitation of Offenders Act), any CRB check will always show up all convictions.
An enhanced CRB check can also show up any other information which a relevant agency deems to be pertinent. For example, allegations of improper conduct can appear , even if there's been no criminal conviction.
Chris