If you don't care whether the installation is compliant with the current wiring regs, then maybe it's the only issue for you. As you know, I agree with you that the regs probably do allow oversleeving of the G/Y, even if it is an 'orrible practice - but if the cable without a CPC is considered non-compliant, then it is non-compliant regardless of considerations of core colours/identification.No John, it's the only issue. Can the green and yellow be over-sleeved or not ? NIC say yes for heating controls.
Kind Regards, John