dfk41 - Open the bottom - I think it’s a secure torx 20. unplug it all the wires, take pictures before hand. Undo the screws and remove the heating element. Find which gasket it’s required - there are two types. Clean it all, replace the element gasket and reconnect everything.
Also check where the water is coming from you never know, might be as simple as the pstat not being tight enough, or not being there. :-)
Unless you open her up, hard to tell.
Good luck. theespressoshop.co.uk stocks everything you need.
PS: I had two of those in the past.
N.B.: You’ll see the manufacture date of the machine written by hand, or on a sticker, in the base of the machine, hidden by the plastic cover which you need to unscrew to gain access to it.