Rational Combination Ovens / Combi Ovens for Food Service, the UK' Top Catering Equipment Supplier. Rational, Combi ovens, SCC Range (Self-Cooking-Centres) and the CM Range ( Combi-Master)Gas and Electric combination ovens for restaurants, hotels, bars and canteens. Site Surveys, Installation, Servicing and prompt repairs. The top catering equipment supplier for SCC Packages and CM Packages.