DS EN 13203-3:2010 Solar Supported Gas-Fired Domestic Appliances Producing Hot Water - Appliances Not Exceeding 70 Kw Heat Input And 500 Litres Water Storage Capacity - Part 3: Assessment Of Energy Consumption Pertains to solar supported gas-fired appliances producing domestic hot water. It also applies to a system marketed as single unit or a system fully specified by a manufacturer that has a gas heat inp