DS EN 13203-1:2006 Gas-Fired Domestic Appliances Producing Hot Water - Appliances Not Exceeding 70 Kw Heat Input And 300 L Water Storage Capacity - Part 1: Assessment Of Performance Of Hot Water Deliveries Pertains to gas-fired appliances producing domestic hot water. It also applies to both instantaneous and storage appliances; water-heaters and combination boilers that have heat input not exceeding 70