zanussi built-in F/F barely cooling.

Model zi 918/12K…type B256946….S/No. 24900219.

This built-in unit has the “zig-zag” pipe and fine “slats” shelf arrangement between the freezer-baskets, also there is no air- duct between the freezer and fridge sections…..back of fridge is smooth , with a built-in drain chute at the bottom and a distinct hot area can be felt on the back-panel ,a little above the chute.

the freezer is barely making frost on the topmost shelf and I suspect the compressor overheat “Klixon” safety-‘stat is cutting-in.

My diagnosis is that the gas has leaked and I need an engineer to trace/rectify the leak and regas.

Any suggestions , please?……I also have an Electra F/F (freestanding) with similar problems….this one is definitely a single-compressor type and the comp. overheat ‘stat is cutting-in.