Customer wants existing storage heater circuits moved over to on-peak. He is having some fancy eco heaters that i am not fitting installed by another party and they, as far he knows, only require an on-peak supply. The existing fuse box does not have rcd protection. If i change it over will it need RCD protection.( i don't think it does as i am not changing any circuit wiring) i appreciate it would be a C3 on a report as it is because of cable depths. The cables obviously are already in place with 20amp switches on.