Russell Hobbs 3122 o ring bonding?

I have a Russell Hobbs 3122 kettle it blew the 13A fuse in the plug. It would appear on inspection that the o ring sealing between the element and the body of the kettle is leaking, causing water to find its way to the switch. The o ring itself is still in good condition so I cleaned it all up and am ready to put it back together but i am not sure the type of sealant used to make a good bond to the o ring to prevent any further leaks. PS I have tried it just fitting the o ring without any sealant but it still leaks. Thank you to anyone that can help.