UK I replaced the light and now my heater switch won't switch on.

[Deleted member 105166]

Please explain how a spur off a 32a ring circuit is permitted then? It is permitted because the requirements for fault protection are met and overload protection is afforded by the fact that the load is restricted to 2x13a fused loads, =26a maximum. Same applies to the OP's circuit except overload protection is afforded by one, not two 13a fuses =13a.

Reading through this topic again, I do see where you are coming from.
Do you agree with my understanding being, if the OP created a fused spur, at the origin of the circuit in this case, i.e. spurred at the 32A MCB, then the 1.5 T/E is acceptable and in line with OSG H2.3. However if he had removed the ring final conductors from the MCB, the cable and FCU in question is no longer a fused spur on an RFC, and is now a radial circuit, either requiring a 20A CPD, alternatively be wired in 4.0mm T/E, as per Table H2.1
Happy to stand corrected, if I have misunderstood.

 

[fairlight]

Thanks for your measured reply. I do not have the BBB to hand for the reg no's but overload protection to any circuit can be omitted if the load is fixed, or if the load is restricted by a downstream device. So if the OP's circuit is a radial serving a single 13a fcu then it will comply on a 32a OCPD as long as fault protection is afforded, which it almost certainly will be. That said same as you, I'd put it on a 16a device, but the advise given to the OP that putting it on a 32a is a safety issue and incorrect is wrong. It would comply.
I'm afraid your comment that a spur from the MCB is a fused spur is incorrect, it's an unfused spur. A fused spur is an extension to a ring circuit spur fed through a 13a fcu, it can serve any number of points on the load side of the fcu