Had the same problem with an Idesit condenser washer/dryer, clothes never came out really dry. OK I could leave them over the radiators overnight if the heating system was on but far from ideal.
Luckily it died and I got a refund, bought a standard washing machine and an Indesit 4Kg normal tumble drier, there’s only 2 of us and not a lot of room in the bungalows kitchen. It does a great job and haven’t really noticed any increase in the amount of electricity we use.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!