Well, it would help if you started from the premise that there is no such animal as a PT C of A any more.
Art 157 (3)(c) of the ANO deals with hiring of aircraft
(3) Subject to the provisions of this article and articles 158 to 163, an aircraft in flight shall for the purposes of this Order be deemed to fly for the purposes of public transport:.............
(c) for the purposes of Part 3 of this Order (other than articles 19(2) and 20(2)), if valuable consideration is given or promised for the primary purpose of conferring on a particular person the right to fly the aircraft on that flight (not being a singleseat aircraft of which the maximum weight authorised does not exceed 910 kg) otherwise than under a hire-purchase or conditional sale agreement.
Art 162 of the ANO contains the exemptions for group owned aircraft.
ergo:- Renting an a/c out is classed as PT unless it falls within any of the exemptions so if your aircraft fulfils the maintenance requirements for PT you can rent it out without relying on any of the exemptions. Art 14 (1) (b) requires a certificate of maintenance review to be valid if the a/c is to be used for PT.