prEN 15420

Gas-fired central heating boilers - Type C boilers of nominal heat input exceeding 70 kW, but not exceeding 1000 kW

This standard specifies the requirements and test methods concerning, in particular the construction, safety, fitness for purpose, and rational use of energy, as well as the classification and marking of gas-fired central heating boilers that are fitted with atmospheric burners, fan assisted atmospheric burners or fully premixed burners, and are hereafter referred to as "boilers".This standard applies to boilers of type C:- that use one or more combustible gases of the three gas families;- that have a nominal heat input (on the basis of net caloric value)exceeding 70 kW, but not exceeding 1000 kW, including modular boilers;- where the temperature of the heat transfer fluid does not exceed 105°C during normal operation;- where the maximum operating pressure in the water circuit does not exceed 6 bar;- which can give rise to condensation under certain circumstances.The standard applies to boilers designed for sealed water systems or for open water systems.The standard does not contain all the requirements necessary for boilers:- intended to be installed in the open or in living rooms;- permanently fitted with more than one flue outlet;- of the condensing type;- intended to be connected to a common flue having mechanical extraction;- type C41, C51, C61, C7, and C81 boilers;- fitted with a forced draught burner in accordance with EN 676;- producing hot water for domestic purposes.This standard only covers type testing.

Heizkessel für gasförmige Brennstoffe - Heizkessel der Bauart C mit einer Nennwärmebelastung größer als 70 kW aber nicht größer als 1 000 kW

Diese Norm behandelt die Anforderungen und die Prüfmethoden im Hinblick auf die Konstruktion, die Sicherheit, die Gebrauchstauglichkeit und den wirtschaftlichen Einsatz von Energie sowie die Klassifizierung und die Kennzeichnung von gasbeheizten Zentralheizungskesseln mit atmosphärischen Brennern, mit gebläseunterstützten atmosphärischen Brennern oder mit voll vorgemischten Brennern, die im weiteren Verlauf als Kessel bezeichnet werden.
Diese Norm behandelt, wie in 4.2 aufgelistet, Kessel der Bauart C:
-   die ein oder mehrere Brenngase der drei Gasfamilien bei den in den Tabellen 14 und 15 angegebenen Drücken verwenden;
-   die Nennwärmebelastung (bezogen auf den Heizwert) über 70 kW, aber nicht über 1000 kW (einschließlich der Kombikessel) haben;
   bei denen die Temperatur der Wärme übertragenden Flüssigkeit beim üblichen Betrieb 105 °C nicht überschreitet;
-   bei denen der höchste Betriebsdruck im Wasserkreislauf 6 bar nicht überschreitet;
-   bei denen unter bestimmten Umständen Kondensation eintreten kann.
Die Norm gilt sowohl für Kessel mit geschlossenem als auch mit offenem Wasserkreislauf.
Diese Norm enthält nicht alle für Kessel erforderlichen Anforderungen:
-   die im Freien oder in Wohnräumen aufgestellt werden;
-   die dauerhaft mit mehr als einem Abgasstutzen ausgerüstet sind;
-   der Bauart Brennwertkessel;
-   die an eine gemeinsame Abgasanlage mit mechanischer Abgasabführung anzuschließen sind;
-   der Bauarten C41, C51, C61 C71 und C81;
-   die in Übereinstimmung mit EN 676 mit einem Gebläsebrenner ausgerüstet sind;
-   die Warmwasser für den sanitären Bedarf erzeugen.
Diese Norm gilt nur für Typprüfungen.

Chaudières de chauffage central utilisant les combustibles gazeux - Chaudières de type C dont le débit calorifique nominal est supérieur à 70 kW, mais inférieur ou égal à 1000 kW

Plinski kotli za centralno gretje - Tip kotlov C z imensko močjo nad 70 kW do vključno 1000 kW

General Information

• Status: Not Published
• Technical Committee: CEN/TC 109 - Central heating boilers using gaseous fuels
• Drafting Committee: CEN/TC 109/WG 2 - Non-domestic central heating boilers using gaseous fuels
• Current Stage: 4098 - Decision to abandon - Enquiry
• Start Date: 24-Jul-2008
• Completion Date: 24-Jul-2008
• Directive: 90/396/EEC - Appliances burning gaseous fuels
• Ref Project: oSIST prEN 15420:2006 - Gas-fired central heating boilers - Type C boilers of nominal heat input exceeding 70 kW, but not exceeding 1000 kW

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 15420:2006
01-marec-2006
3OLQVNLNRWOL]DFHQWUDOQRJUHWMH7LSNRWORY&]LPHQVNRPRþMRQDGN:GR
YNOMXþQRN:
Gas-fired central heating boilers - Type C boilers of nominal heat input exceeding 70 kW,
but not exceeding 1000 kW
Heizkessel für gasförmige Brennstoffe - Heizkessel der Bauart C mit einer
Nennwärmebelastung größer als 70 kW aber nicht größer als 1 000 kW
Chaudieres de chauffage central utilisant les combustibles gazeux - Chaudieres de type
C dont le débit calorifique nominal est supérieur a 70 kW, mais inférieur ou égal a 1000
kW
Ta slovenski standard je istoveten z: prEN 15420
ICS:
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
97.100.20 Plinski grelniki Gas heaters
oSIST prEN 15420:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 15420:2006

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oSIST prEN 15420:2006
EUROPEAN STANDARD
DRAFT
prEN 15420
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2006
ICS

English Version
Gas-fired central heating boilers - Type C boilers of nominal heat
input exceeding 70 kW, but not exceeding 1000 kW
Chaudières de chauffage central utilisant les combustibles
gazeux - Chaudières de type C dont le débit calorifique
nominal est supérieur à 70 kW, mais inférieur ou égal à
1000 kW
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 109.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15420:2006: E
worldwide for CEN national Members.

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oSIST prEN 15420:2006
prEN 15420:2005 (E)
Contents
1 Scope. 7
2 Normative references . 7
3 Definitions. 9
3.1 Combustible gases . 9
3.2 Constituent parts of the boiler. 11
3.2.1 Gas supply. 11
3.2.2 Air supply and combustion products evacuation . 12
3.2.3 Adjusting, control and safety devices . 13
3.3 Operation of the boiler. 16
3.3.1 Gas rates. 16
3.3.2 Outputs. 17
4 Classification of boilers. 20
4.1 Gases and categories. 20
4.2 Mode of air supply and evacuation of the combustion products . 20
4.2.1 General. 20
4.2.2 Type of installation of the boiler. 21
4.2.3 Presence and position of a fan. 22
)
4.3 Classification according to operating conditions . 22
4.3.1 Standard boiler. 22
4.3.2 Low-temperature boiler . 22
4.3.3 Gas condensing boiler . 22
4.4 Modular boiler . 22
5 Constructional requirements. 22
5.1 General. 22
5.2 Conversion to different gases . 22
5.3 Materials and method of construction. 23
5.3.1 General. 23
5.3.2 Materials and thicknesses of walls or tubes under water pressure . 23
5.3.3 Thermal insulation . 32
5.4 Combustion products evacuation duct . 33
5.4.1 Stability under mechanical loading. 33
5.4.2 Stability under exposure to heat .33
5.4.3 Corrosion resistance . 33
5.4.4 Resistance to condensate and moisture under normal operating conditions. 33
5.5 Design . 33
5.5.1 General. 33
5.5.2 Modular boilers . 34
5.6 Use and servicing . 34
5.7 Connections to the gas and water pipes. 34
5.7.1 General. 34
5.7.2 Connections to the gas pipe. 34
5.7.3 Connections to the central heating circuit. 35
5.8 Soundness. 35
5.8.1 Soundness of the gas circuit. 35
5.8.2 Soundness of the combustion circuit. 35
5.9 Supply of combustion air and the evacuation of the combustion products . 36
5.9.1 General. 36
5.9.2 Air supply and combustion products evacuation duct. 36
5.9.3 Terminal . 36
5.9.4 Terminal guard . 36
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oSIST prEN 15420:2006
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5.9.5 Fitting piece . 37
5.9.6 Special requirements for certain components of boilers with a fan . 37
5.9.7 Condensate discharge. 38
5.10 Checking the state of operation .38
5.11 Drainage. 38
5.12 Electrical equipment. 39
5.13 Operational safety in the event of failure of the auxiliary energy. 39
5.14 Adjusting, control and safety devices . 39
5.14.1 General. 39
5.14.2 Adjusters and range rating devices. 39
5.14.3 Gas circuit. 40
5.14.4 Gas pressure governor. 41
5.14.5 Ignition devices . 42
5.14.6 Flame supervision systems . 42
5.14.7 Thermostats and water temperature limiting devices. 43
5.15 Burners . 44
5.16 Pressure test points. 44
5.17 Chemical composition of the condensate. 44
6 Operational requirements . 45
6.1 General. 45
6.2 Soundness. 45
6.2.1 Soundness of the gas circuit. 45
6.2.2 Soundness of the combustion circuit. 45
6.2.3 Soundness of the water circuit. 46
6.3 Nominal, maximum and minimum heat inputs, and nominal output. 46
6.3.1 Nominal heat input or maximum and minimum heat inputs . 46
6.3.2 Adjustment of the heat input by the downstream pressure. 46
6.3.3 Ignition rate. 46
6.3.4 Nominal output. 46
6.3.5 Gas pressure governor. 47
6.4 Safety of operation. 47
6.4.1 Limiting temperatures . 47
6.4.2 lgnition – Cross-lighting – Flame stability. 48
6.4.3 Pre-purge . 49
6.4.4 Functioning of a permanent ignition burner when the fan stops during the
standby time . 50
6.5 Adjusting, control and safety devices . 50
6.5.1 General. 50
6.5.2 Ignition devices . 50
6.5.3 Flame supervision devices . 51
6.5.4 Ignition burner and ignition rates. 53
6.5.5 Air proving . 53
6.5.6 Gas pressure switches. 55
6.5.7 Control thermostat and safety temperature limiter . 55
6.5.8 Condensate discharge blockage. 56
6.6 Combustion . 56
6.6.1 Carbon monoxide. 56
6.6.2 Other pollutants . 57
6.7 Useful efficiencies. 57
6.7.1 Useful efficiency at the nominal heat input. 57
6.7.2 Useful efficiency at part load . 57
6.8 Criteria for condensation in the flue .58
6.9 Resistance of the materials to pressure. 58
6.9.1 General. 58
6.9.2 Boilers of sheet steel or non-ferrous metals . 58
6.9.3 Boilers of cast iron and cast materials. 58
6.10 Hydraulic resistance. 59
6.11 Condensation in the boiler. 59
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oSIST prEN 15420:2006
prEN 15420:2005 (E)
7 Test methods. 59
7.1 General. 59
7.1.1 Characteristics of the reference and limit gases. 59
7.1.2 General test conditions . 65
7.2 Soundness. 68
7.2.1 Soundness of the gas circuit. 68
7.2.2 Soundness of the combustion circuit. 69
7.2.3 Soundness of the water circuit. 70
7.3 Nominal, maximum and minimum heat inputs and nominal output. 70
7.3.1 The nominal heat input or the maximum and minimum heat inputs. 70
7.3.2 Adjustment of the heat input by the downstream pressure. 71
7.3.3 Minimum ignition rate. 71
7.3.4 Nominal output. 72
7.3.5 Gas governor. 72
7.4 Safety of operation. 72
7.4.1 Limiting temperatures . 72
7.4.2 Ignition - Cross-lighting - Flame stability . 74
7.4.3 Pre-purge . 77
7.4.4 Functioning of a permanent ignition burner when the fan stops during standby
time. 78
7.5 Adjusting, control and safety devices . 78
7.5.1 General. 78
7.5.2 Ignition devices . 78
7.5.3 Flame supervision device . 79
7.5.4 Ignition burner and ignition rates. 81
7.5.5 Air proving device. 81
7.5.6 Gas pressure switches. 83
7.5.7 Control thermostat and safety temperature limiter . 83
7.5.8 Condensate discharge blockage. 84
7.6 Combustion . 85
7.6.1 Carbon monoxide. 85
7.6.2 Other pollutants . 89
7.7 Useful efficiencies. 92
7.7.1 Useful efficiency at the nominal heat input. 92
7.7.2 Useful efficiency at part load . 93
7.8 Criteria for condensation in the flue .99
7.8.1 Determination of flue losses. 99
7.8.2 Minimum temperature of the combustion products. 100
7.9 Resistance of materials to pressure . 100
7.9.1 General. 100
7.9.2 Boilers of sheet steel or non-ferrous metals . 100
7.9.3 Boilers of cast iron and cast materials. 100
7.10 Hydraulic resistance. 101
7.11 Condensation in the boiler. 101
8 Marking and instructions . 101
8.1 Marking of the boiler. 101
8.1.1 General. 101
8.1.2 Data plate . 101
8.1.3 Supplementary marking . 103
8.1.4 Packaging . 105
8.1.5 Warnings on the boiler and on the packaging. 105
8.1.6 Other information. 105
8.2 Instructions. 105
8.2.1 Technical instructions for the installer. 105
8.2.2 For installation of the combustion circuit . 106
8.2.3 Use and maintenance instructions for the user . 107
8.2.4 Conversion instructions. 108
Annex A (informative) National situations . 123
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Annex B (informative) Special national conditions. 129
Annex C (informative) A-deviations . 130
Annex D (informative) Classification of type C boilers. 131
Annex E (informative) Practical method of calibrating the test rig to enable the heat loss
D to be determined . 138
p
Annex F (informative) Main symbols and abbreviations used. 139
Annex G (informative) Compilation of test conditions . 140
Annex H (informative) Valving. 143
Annex I (informative) Determination of the heat losses from the test rig of the indirect
method and the contributions of the circulating pump of the test rig . 150
Annex J (informative) Means of determining the ignition time at full rate. 151
Annex K (informative) Example of calculation of the weighting factors for a boiler with
several rates . 152
Annex L (informative) Calculation of conversions of NOx. 154
Annex M (normative) Test apparatus for type C boilers (see 7.4.2.3.3) . 155
2
Annex N (informative) Requirements and test methods for separate air supply and
combustion products evacuation ducts of type C boilers . 156
6
Annex O (informative) Use of test gases. 161
Annex ZA (informative) Clauses of this European Standard addressing essential
requirements or provisions of EU Directives. 162


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oSIST prEN 15420:2006
prEN 15420:2005 (E)
Foreword
This document (prEN 15420:2005) has been prepared by Technical Committee CEN/TC 109 "Central
heating boilers using gaseous fuels", the secretariat of which is held by NEN.
This document is currently submitted to the CEN Enquiry.
It was established to deal with aspects related to:
 safety;
 rational use of energy;
 fitness for purpose.
Other types of boilers are dealt with in separate standards.
This draft European standard has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association, and supports and supports Essential
Requirements of EU
...