There are a variety of Zanussi dishwashers, each with a different element. Having the model number may help better but see here for some typical examples, which may help you to identify yours:
http://shop.zanussi.co.uk/category/Dishwashers/Dishwashers/Heating%20Elements
The ones in a tube are likely connected to pipework in side the machine. The naked wriggly elements will be mounted low down in the machine tank.
this MAY help. (There's probably plenty more videos out there. just search.
https://www.youtube.com/watch?v=bqmaFLmQQZw
Anon, July 2016
