Delonghi Microwave with Gill and Convection oven

I used the convection oven function on this Microwave last week, tried again today and it trips the fuse.

Tried on different socket circuits (upstairs, downstairs and kitchen) and it trips, but only when using the convection oven function, microwave and grill functions fine.

Clearly an appliance fault as other devices draw more than the convection oven should with no trips.

Anything straightforward that can rectify this? We’re in the middle of building works and it’s the one thing we were counting on to have something cooked in the oven when it’s so cold outside and we have no central heating!