Replacing ceramic hob

[Grumps]

FIL's old ceramic hob is cracked, and he has bought a new one. Well, he bought it 9 months ago, but only needs it fitting now. Does Prat P allow for DIY replacement of like-for-like, even in kitchens? The old hob looks like it was wired with 6mm2. The new (and old) hob says

7.1kW(max), which is ok for 6mm stuff, but it would appear to go via a 20A fuse in the fuse box. From my (limited) experience with those cooker switches, they are quite heavy to operate, but the switch that he has is really quite smooth. Could it be an inappropriate switch is already there, or are some smoother in operation than others? Ta.

[Owain]

Hobs are subject to quite high diversity rating, because even if all the rings are in use they click on and off with their simmerstats.

20A switch significantly less hefty than a 45A cooker switch. I find the ones with 'toggles' easier to operate than rockers.

Owain