NEN EN 26 : 2015

Foreword
1 Scope
2 Normative references
3 Definitions
    3.1 instantaneous water heater
    3.2 characteristics of the gas and electricity supplies
    3.3 gas circuit
    3.4 adjusting, control and safety devices
    3.5 stages of operational and safety sequences
    3.6 burners
    3.7 combustion circuit
    3.8 water circuit
    3.9 soundness of the gas circuit
    3.10 operation
4 Classification of water heaters
    4.1 Classification of gases
    4.2 Appliance categories
    4.3 Mode of supply of the combustion air and evacuation
    4.4 Water pressure
5 Marking and instructions
    5.1 Appliance marking
    5.2 Instructions
    5.3 Presentation
6 Constructional requirements
    6.1 General
    6.2 Adjusting, control and safety devices
    6.3 Main burner
7 Operational requirements
    7.1 General
    7.2 Soundness
    7.3 Heat inputs
    7.4 Temperature of the control knobs
    7.5 Temperature of the adjusting, control and safety
          devices
    7.6 Temperature of the appliance case, the wall on
          which it is installed and adjacent walls
    7.7 Ignition - cross-lighting - Flame stability
    7.8 Adjusting, control and safety devices
    7.9 Combustion
    7.10 Soot deposition
8 Rational use of energy
    8.1 Heat input of ignition burners
    8.2 Efficiency
9 Fitness for purpose
    9.1 Constructional characteristics
    9.2 Operational characteristics
Annexes
A (informative) National situations (see 4.1)
    A.1 Marketing of the categories listed in the body
          of the European Standard in different countries
          see 4.2.1)
    A.2 Appliance supply pressures corresponding to the
          categories given in A.1(see 4.2.1)
    A.3 Particular categories marketed nationally or
          locally (see 4.2.1, 4.2.4, 5.1.1 and 7.1.3.1)
    A.4 Test gases and pressures corresponding to the
          special categories given in A.3 (see 4.2.1,
          7.1.2 and 7.1.4)
    A.5 Additional marking corresponding to the
          particular categories given in A.3 (see 5.1.2)
    A.6 Particular conditions
    A.7 Gas connection conditions in common use in the
          various countries
    A.8 Water connection conditions in common use in the
          various countries (see 9.1.1)
    A.9 Flue pipe diameters in force in the various
          countries (see 2.1.7.3)
B (normative) Test apparatus for type C11 appliances
    (see 7.7.3.2)
C (normative) Test apparatus for type C21 appliances
    (see 7.7.4.2)
D (normative) Description of the sealed room for the tests
    of type Aas appliances (see 7.8.10.1.2.1)
    D.1 Configuration of the sealed room
    D.2 Soundness of the room
    D.3 Effectiveness of mixing
    D.4 Equipment of the room
E (informative) Soundness of the gas circuit test -
    Volumetric method (see 7.1.5.4 and 7.2.1.2)
    E.1 Equipment
    E.2 Test method
F (informative) Principal symbols and abbreviations used
G (informative) Guidelines for extension to other
    categories (see 7.1.3.1)
H (informative) Protection against electric shock for
    high voltage ignition devices (see 6.1.10)
    H.1 Protection against accessibility to live
          parts (see 8)
J (informative) Examples of marking on the appliance
    J.1 Data plate
    J.2 Additional marking (see 5.1.2 and J.1)
K (normative) Marking on the appliance and its packaging -
    Indication of the gas types in accordance with the
    uses declared by the countries in their official
    language(s)(see note 3 of table 2 from 5.1.2)
ZA (informative) Clauses of this European Standard
    addressing Essential Requirements or other provisions
    of EU Directives

Specifies the specifications and test methods concerning the construction, safety, rational use of energy and fitness for purpose, and also the classification and marking of gas-fired instantaneous water heaters for sanitary uses, hereafter called 'water heaters'.