Gas-fired central heating boilers - Part 2-3: Specific standard for hybrid space heating appliances combining a gas fired appliances and heat pump in a product; German and English version prEN 15502-2-3:2021


This European Standard specifies, the requirements and tests methods concerning, in particular, theconstruction, safety, fitness for purpose, and rational use of energy, as well as the classification andmarking of hybrid gas boilers or packages marketed as single product including one or several casings.The hybrid gas boiler is composed by:- A gas boiler as primary heat generator which could supply the heat demand in all operatingconditions;- An electrical or gas heat pump, as a secondary heat generator, which has not to fulfil the heat demandin all operating conditions;- A control unit which optimise the operation of the generators.Note to entry See Table 3 of the Commission Regulation (UE) No 813/2013 - Outlet temperature of55°C, Inlet temperature of 47°C and outdoor air of 7°C).Due to its construction the hybrid gas boiler shall be able to reach 80°C flow temperature.The gas boiler as part of the hybrid gas boiler covered by this European Standard is a gas-fired centralheating boilers from the types C1 up to C9 and the types B2, B3 and B5, according to the classification inFprEN 1749:2018:a) that have a nominal heat input (on the basis of net calorific value) not exceeding 70 kW;b) that use one or more combustible gases of the three gas families at the pressures stated in EN437;c) where the temperature of the heat transfer fluid does not exceed 105 °C during normaloperation;d) where the maximum operating pressure in the water circuit does not exceed 6 bar;e) which shall be classified as gas boiler;f) which are intended to be installed either indoors or outdoors in a partially protected place;g) which may include the facility to produce hot water, either by the instantaneous or storageprinciple, the whole being marketed as a single unit;h) which are designed for either sealed water systems or for open water systems.This European Standard provides requirements for boilers with known constructions. For boilers withany alternative constructions, which might not fully be covered by this standard, the risk associatedwith this alternative construction needs to be assessed.An example of an assessment methodology, based upon risk assessment and which covers the essentialrequirements of the Gas Appliance Directive, is given in Clause 11.This European Standard does not cover all the requirements for:Appliances that are intended to be connected to gas grids where the quality of the distributed gas islikely to vary to a large extent over the lifetime of the appliance (see Annex DD);a) appliances using flue dampers;b) appliances of the types B21, B31, B51, C21, C41, C51, C61, C71 and C81;c) appliances incorporating flexible plastic flue liners;d) appliances designed to become connected to a combined flue duct system that is designed tooperate under overpressure (for example Ca)).This European Standard specifies minimum operating requirements which ensure that the products arefit for the use designated by the manufacturer when used for space heating and/or DHW production.This part specifies the common requirements and test methods concerning, in particular theconstruction, safety, fitness for purpose, and rational use of energy.This European Standard is to be used in conjunction with:a) the gas generator, the generic part EN 15502-1 and specific Part 2-1 and Part 2-2.b) the heat pump, EN 14511-4, EN 378-1 to EN 378-4 and EN 14825.c) electrical safety, EN 60335-1, EN 60335-2-102, EN 60335-2-40, EN 60335-2-40/A2 andEN 60204-1.d) for domestic hot water production, EN 13203-5.





Planned document number

DIN EN 15502-2-3

Project number


Responsible national committee

NA 032-03-01 AA - Domestic, Commercial and Industrial Gas Utilisation 

Responsible european committee

CEN/TC 109/WG 1 - Domestic central heating boilers using gaseous fuels 

draft standard

Gas-fired central heating boilers - Part 2-3: Specific standard for hybrid space heating appliances combining a gas fired appliances and heat pump in a product; German and English version prEN 15502-2-3:2021
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