Hillsome Limited

Your fuse box has to meet atleast the 17edition as your fuse box has to be rcd protected.

the recommended size of your fuse box has to be in tandem with the size of your house. for instance you might need a 6, 10,or 16 way populated consumer unit. basically if your consumer unit isn't rcd protected then your need an upgrade or a replacement

Your bathroom is a special location going by regulations. my best advice is hire a qualified electrician. but if you are confident enough to diy then at the end ensure the job is certified by a third party. thanks

My best advice to you is hire an electrician to fix the problem as well as replacing the old lighting to an led.

Well i believe 500 is a good quote inclusive of supply of the new consumer unit

Yes your cooker maybe faulty. the element(s) of your cooker hob may have gone bad. and now that your fuse box has just been upgraded certainly to an rcd protected type, it's now being able to detect the earth fault from your cooker every time you turn it on it definitely going to trip it off.