UNI EN 483 : 2008

Foreword
1 Scope
2 Normative references
3 Definitions
  3.1 Reference conditions
  3.2 Combustible gases
      3.2.1 Test gases
      3.2.2 Reference gas
      3.2.3 Limit gas
      3.2.4 Calorific value
      3.2.5 Relative density
      3.2.6 Wobbe index
      3.2.7 Gas pressures
  3.3 Constituent parts of the boiler
      3.3.1 Gas supply
      3.3.2 Air supply and combustion products evacuation
      3.3.3 Adjusting, control and safety devices
  3.4 Operation of the boiler
      3.4.1 Gas rates
      3.4.2 Outputs
      3.4.3 Useful efficiency
      3.4.4 Gas combustion
      3.4.5 Times
      3.4.6 Spark restoration
      3.4.7 Recycling
      3.4.8 Controlled shutdown
      3.4.9 Safety shutdown
      3.4.10 Locking out
      3.4.11 De-energized to trip principle
      3.4.12 Purge
      3.4.13 Air proving device
      3.4.14 Gas/air ratio control
      3.4.15 Nominal voltage
      3.4.16 Living space dedicated boiler
  3.5 Country of destination
      3.5.1 Direct country of destination
      3.5.2 Indirect country of destination
4 Classification of boilers
  4.1 Gases and categories
  4.2 Mode of air supply and evacuation of the
      combustion products
      4.2.1 General
      4.2.2 Type of installation of the boiler
      4.2.3 Presence and position of a fan
  4.3 Maximum water-side operating pressure
  4.4 Expansion system
5 Constructional requirements
  5.1 General
  5.2 Conversion to different gases
  5.3 Materials and thicknesses
      5.3.1 General
      5.3.2 Materials and thickness of sheet metal walls or
            tubes under water pressure for boilers of
            pressure class 3
      5.3.3 Thermal insulation
      5.3.4 Control and safety devices
      5.3.5 Separate combustion products evacuation duct
      5.3.6 Design
  5.4 Method of construction
      5.4.1 Use and servicing
      5.4.2 Connections to the gas and water pipes
      5.4.3 Soundness
      5.4.4 Supply of combustion air and evacuation of the
      5.4.5 Checking the state of operation
      5.4.6 Drainage
      5.4.7 Operational safety in the event of failure of the
            auxiliary energy
 5.5 Electrical equipment
 5.6 Requirements for adjusting, control and
     safety devices
     5.6.1 General
     5.6.2 Adjusters and range-rating devices
     5.6.3 Gas circuit
     5.6.4 Gas governor
     5.6.5 Ignition devices
     5.6.6 Flame supervision devices
     5.6.7 Thermostats and water temperature limiting devices
     5.6.8 Remote control
     5.6.9 Expansion vessel and pressure gauge
 5.7 Burners
 5.8 Pressure test points
6 Operational requirements
 6.1 General
 6.2 Soundness
     6.2.1 Soundness of the gas circuit
     6.2.2 Soundness of the combustion circuit
     6.2.3 Soundness of the water circuit
 6.3 Heat inputs and heat outputs
     6.3.1 The nominal heat input or the maximum and minimum heat
           input
     6.3.2 Adjustment of the heat input by the downstream gas
           pressure
     6.3.3 Ignition rate
     6.3.4 Nominal output
 6.4 Safety of operation
     6.4.1 Limiting temperatures
     6.4.2 Ignition - Cross lighting - Flame stability
     6.4.3 Reduction of the gas pressure
     6.4.4 Defective closure of the gas valve immediately
           upstream of the main burner
     6.4.5 Pre-purge
     6.4.6 Functioning of a permanent ignition burner when
           the fan stops during the standby time
     6.4.7 Leakage of combustion products for type C[7]
           boilers
 6.5 Adjusting, control and safety devices
     6.5.1 General
     6.5.2 Control devices
     6.5.3 Automatic valves
     6.5.4 Ignition devices
     6.5.5 Flame supervision device
     6.5.6 Gas governor
     6.5.7 Thermostats and water temperature limiting
           devices
     6.5.8 Air proving device
     6.5.9 Functioning of the fan of a type C[4] boiler
 6.6 Combustion
     6.6.1 Carbon monoxide
     6.6.2 Other pollutants
 6.7 Useful efficiencies
     6.7.1 Useful efficiency at the nominal heat input
     6.7.2 Useful efficiency at part load
 6.8 Resistance of the materials to pressure
     6.8.1 General
     6.8.2 Boilers of pressure class 1
     6.8.3 Boilers of pressure class 2
     6.8.4 Boilers of pressure class 3
 6.9 Hydraulic resistance
7 Test methods
 7.1 General test conditions
     7.1.1 General
     7.1.2 Characteristics of the reference and limit gases
     7.1.3 Installation of the boiler
     7.1.4 Gas circuit
     7.1.5 Conduct of the test to obtain a heat input
     7.1.6 Water circuit
     7.1.7 Thermal equilibrium
     7.1.8 Electrical supply
     7.1.9 Uncertainty of measurements
 7.2 Soundness
     7.2.1 Soundness of the gas circuit
     7.2.2 Soundness of the combustion circuit
     7.2.3 Soundness of the water circuit
 7.3 Heat inputs and heat outputs
     7.3.1 Determination of the nominal heat input or the
           maximum and minimum heat input
     7.3.2 Adjustment of the heat input by the downstream
           pressure
     7.3.3 Ignition rate
     7.3.4 Nominal output
 7.4 Safety of operation
     7.4.1 Limiting temperatures
     7.4.2 Ignition - Cross lighting - Flame stability
     7.4.3 Reduction of the gas pressure
     7.4.4 Defective closure of the gas valve immediately
           upstream of the main burner
     7.4.5 Pre-purge
     7.4.6 Functioning of a permanent ignition burner
           when the fan stops during the standby time
     7.4.7 Leakage of combustion products for type
           C[7] boilers
 7.5 Adjusting, control and safety devices
     7.5.1 General
     7.5.2 Control devices
     7.5.3 Automatic valves
     7.5.4 Ignition devices
     7.5.5 Flame supervision device
     7.5.6 Gas governor
     7.5.7 Thermostats and water temperature limiting devices
     7.5.8 Air proving device
     7.5.9 Functioning of the fan of a type C[4] boiler
 7.6 Combustion
     7.6.1 Carbon monoxide
     7.6.2 Other pollutants
 7.7 Useful efficiencies
     7.7.1 Useful efficiency at the nominal heat input
     7.7.2 Useful efficiency at part load
 7.8 Resistance of the materials to pressure
     7.8.1 General
     7.8.2 Boilers of pressure class 1
     7.8.3 Boilers of pressure class 2
     7.8.4 Boilers of pressure class 3
 7.9 Hydraulic resistance
8 Marking and instructions
 8.1 Boiler marking
     8.1.1 General
     8.1.2 Data plate
     8.1.3 Supplementary markings
     8.1.4 Packaging
     8.1.5 Warnings on the boiler and the packaging
     8.1.6 Other information
 8.2 Instructions
     8.2.1 Technical instructions
     8.2.2 User's instructions
     8.2.3 Conversion instructions
     8.2.4 Presentation
Annex A (informative) National situations
Annex B (informative) Particular national conditions
Annex C (informative) Classification of Type C boilers
Annex D (informative) Composition of the gas circuit
Annex E (informative) Compilation of the test conditions
Annex F (normative) Test apparatus for Type C2 boilers
Annex G (informative) Practical method of calibrating the
                      test rig to enable the heat loss Dp
                      to be determined
Annex H (informative) A-deviations
Annex J (informative) Main symbols and abbreviations used
Annex K (informative) Examples for marking
Annex L (informative) Example of calculation of the
                      weighting factors for a boiler with
                      several rates following Table 17
Annex M (informative) Calculation of conversions of NOx
Annex N (informative) Requirements and test methods for
                      separate air supply and combustion
                      products evacuation ducts of Type C6
                      boilers
Annex ZA (informative) Clauses of this European standard
                       addressing essential requirements
                       or other provisions of EU Directives

Defines requirements and test procedures concerned with construction, safety, fitness for purpose and rational energy use, as well as marking and classification of gas-fired central heating boilers fitted with atmospheric burners, fan assisted atmospheric or premixed burners that are hereafter referred to as "boilers".