[www.staffempire.com]-BS EN 625-1996 Gas-fired central heating boilers — Specific requirements for the domestic hot water operation.pdf

BRITISH STANDARDBS EN625:1996Gas-fired central heating boilers Specific requirements for the domestic hot water operation of combination boilers of nominal heat input not exceeding 70 kwThe European Standard EN 625:1995 has the status of a British StandardBS EN 625:1996This British Standard,having been prepared under the direction of the Engineering Sector Board,was published under the authority of the Standards Board and comes into effect on15 April 1996 BSI 08-1999The following BSI references relate to the work on this standard:Committee reference GSE/29Draft for comment 92/71976 DCISBN 0 580 25367 8Committees responsible for this British StandardThe preparation of this British Standard was entrusted to Technical Committee GSE/29,Domestic gas-fired central heating boilers,upon which the following bodies were represented:Association of Manufacturers of Domestic Unvented Supply SystemsEquipment(MODUSSE)Boilers and Radiator Manufacturers Association LimitedBritish Gas plcDepartment of the Environment(Building Research Establishment)Department of the Environment(Property and Buildings Directorate)Department of Trade and Industry(Consumer Safety Unit,CA Division)Electricity AssociationSociety of British Gas IndustriesCo-opted membersAmendments issued since publicationAmd.No.DateCommentsBS EN 625:1996 BSI 08-1999iContentsPageCommittees responsible Inside front coverNational foreword iiForeword 2Text of EN 625 5List of references Inside back coverBS EN 625:1996ii BSI 08-1999National forewordThis British Standard has been prepared under the direction of the Engineering Sector Board and is the English language version of EN 625:1995 Gas-fired central heating boilers Specific requirements for the domestic hot water operation of combination boilers of nominal heat input not exceeding 70 kW,published by the European Committee for Standardization(CEN).EN 625 was produced as the result of international discussion in which the UK took an active part.There has previously been no direct British Standard equivalent to this standard.It is assumed that the execution of the provisions of this document is entrusted to suitably qualified and experienced persons.A British Standard does not purport to include all the necessary provisions of a contract.Users of British Standards are responsible for their correct application.Compliance with a British Standard does not of itself confer immunity from legal obligations.Cross-referencesPublication referred toCorresponding British StandardEN 297:1994BS EN 297:1994 Gas-fired central heating boilers Type B11 and B11BS boilers fitted with atmospheric burners of nominal heat input not exceeding 70 kW.EN 437:1994BS EN 437:1994 Specification for test gases,test pressures and categories of appliance,for gas appliancesSummary of pagesThis document comprises a front cover,an inside front cover,pages i and ii,the EN title page,pages 2 to 16,an inside back cover and a back cover.This standard has been updated(see copyright date)and may have had amendments incorporated.This will be indicated in the amendment table on the inside front cover.w w w.b z f x w.c o mEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 625September 1995ICS 27.060.30;91.140.10;91.140.60Descriptors:Heaters,gas appliances,central heating,water production,boilers,burners,definitions,equipment specifications,performance evaluation,tests,safety,energy,consumption,operating requirements,marking,name plates,classificationsEnglish versionGas-fired central heating boilers Specific requirements for the domestic hot water operation of combination boilers of nominal heat input not exceeding 70 kWChaudires de chauffage central utilisant les combustible gazeux Exigences spcifiques la fonction eau chaude sanitaire des chaudires deux services dont le dbit calorifique nominal est infrieur ou gal 70 kWHeizkessel fr gasfrmige Brennstoffe Spezielle Anforderungen an die Trinkwasserseitige Funktion von Kombi-Kesseln mit einer Nennwrmebelastung kleiner als oder gleich 70 kWThis European Standard was approved by CEN on 1995-03-06.CEN membersare bound to comply with the CEN/CENELEC Internal Regulations whichstipulate the conditions for giving this European Standard the status of anational standard without any alteration.Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to anyCEN member.This European Standard exists in three official versions(English,French,German).A version in any other language made by translation under theresponsibility of a CEN member into its own language and notified to theCentral Secretariat has the same status as the official versions.CEN members are the national standards bodies of Austria,Belgium,Denmark,Finland,France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,Switzerland andUnited Kingdom.CENEuropean Committee for StandardizationComit Europen de NormalisationEuropisches Komitee fr NormungCentral Secretariat:rue de Stassart 36,B-1050 Brussels 1995 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members.Ref.No.EN 625:1995 Ew w w.b z f x w.c o mEN 625:1995 BSI 08-19992ForewordThis European Standard was prepared by Technical Committee CEN/TC 109,Central heating boilers using gaseous fuels,of which the secretariat is held by NNI.Other types of boiler including boilers of higher nominal heat input which are excluded from this European Standard are dealt with in separate standards.This European Standard has been prepared under a mandate granted to CEN by the European Commission and the European Free Trade Association,and supports the essential requirements of the EU Directive.In particular,matters which relate to quality assurance systems,production tests and the certification of auxiliary controls are not dealt with in this standard.In respect of potential adverse effects on the quality of water intended for human consumption,caused by the product covered by this standard:1)This standard provides no information as to whether the product may be used without restriction in any of the member states of the EU or EFTA.2)It should be noted that,while awaiting the adoption of verifiable European criteria,existing national regulations concerning the use and/or the characteristics of this product remain in force.In compliance with the common rules of CEN/CENELEC,the following countries are bound to apply this European Standard:Austria,Belgium,Denmark,Finland,France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,Switzerland and United Kingdom.For relationship with EU Directives,see informative Annex ZA,which is an integral part of this standard.This European Standard shall be given the status of a national standard,either by publication of an identical text or by endorsement,at the latest by March 1996,and conflicting national standards shall be withdrawn at the latest by March 1996.w w w.b z f x w.c o mEN 625:1995 BSI 08-19993ContentsPageForeword 21Scope52Normative references53Definitions53.1Combination boiler53.2“Summer”operating mode53.3Specific rate53.4Nominal domestic hot water heat input53.5Maximum water service pressure53.6Tank53.7Thermal store53.8Temperature relief valve63.9Proportional control of the domestic hot water operation63.10Thermostatic control of the domestic hot water operation63.11Temperature holding thermostat64Constructional requirements64.1Materials and method of construction of components of the domestic water circuit64.2Domestic water connections64.3Soundness of the domestic water circuit64.4Adjusting,control and safety devices for the domestic hot water circuit65Operational requirements65.1General65.2Safety of the domestic hot water circuit75.2.1Instantaneous and storage types75.2.2Instantaneous type75.2.3Storage type75.3Rational use of energy75.3.1Useful efficiency75.3.2Losses75.4Fitness for purpose75.4.1Instantaneous and storage types Specific rate75.4.2Instantaneous type76Test methods86.1General86.1.1Adjustment of the domestic water pressure8Page6.1.2Operation of the boiler86.2Safety of the domestic hot water circuit86.2.1Instantaneous and storage types86.2.2Instantaneous type86.2.3Storage type96.3Rational use of energy96.3.1Useful efficiency96.3.2Losses96.4Fitness for purpose116.4.1Instantaneous and storage types Specific water rate116.4.2Instantaneous type117Marking and instructions127.1Data plate of the boiler and/or the tank127.2Instructions127.2.1Technical instructions for the installer127.2.2Operating instructions for the user12Annex ZA(informative)Clauses of this European Standard addressing essential requirements or other provisionsof EU Directives14Figure 1 Illustration of the test tank rig see 6.3.2.1.3 a)13Table ZA.115Table ZA.216Table ZA.316w w w.b z f x w.c o m4blankw w w.b z f x w.c o mEN 625:1995 BSI 08-199951 ScopeThis standard supplements standards EN 297,prEN 483 and prEN 677,hereafter called“boiler standards”.It specifies the supplementary requirements and tests for the construction,safety,rational use of energy,fitness for purpose,classification and marking related to the domestic hot water operation of combination boilers.The domestic hot water is produced by either the instantaneous or storage principle.The domestic hot water production is integrated or coupled,and the whole being marketed as a single unit.This standard does not apply to two appliances included in the same case which operate independently of each other,a boiler and a water heater,even if they have a common flue.This standard only covers type testing.2 Normative referencesThis European Standard incorporates by dated or undated reference,provisions from other publications.These normative references are cited at the appropriate places in the text and the publications are listed hereafter.For the dated references,subsequent amendments to or revisions of any of these publications apply to this standard only when incorporated in it by amendment or revision.For undated references,the latest edition of the publication referred to applies.EN 297:1994,Gas-fired central heating boilers Type B11 and B11BS boilers fitted with atmospheric burners of nominal heat input not exceeding 70 kW.EN 297/prA2,Gas-fired central heating boilers Type B11 and B11BS boilers fitted with atmospheric burners of nominal heat input not exceeding 70 kW(determination of efficiency).EN 437,Test gases Test pressures Appliance categories.prEN 483,Gas-fired central heating boilers with atmospheric burners Type C boilers of nominal heat input not exceeding 70 kW.prEN 677,Gas-fired central heating boilers Specific requirements for condensing boilers with nominal heat input not exceeding 70 kW.ISO 7-1,Pipe threads where pressure-tight joints are made on the threads Part 1:Designation,dimensions and tolerances.ISO 228-1,Pipe threads where pressure-tight joints are not made on the threads Part 1:Designation,dimensions and tolerances.ISO 274,Copper tubes of circular section Dimensions.3 DefinitionsFor the purposes of this standard the following definitions apply.3.1 combination boilerboiler designed both for central heating and for the production of domestic hot water.Depending on its type of domestic hot water production,the combination boiler is classed as follows,in accordance with the manufacturers declaration instantaneous typeCombination boilers which can continuously supply the specific domestic hot water rate D stated by the manufacturer.storage typeCombination boilers which can intermittently supply the specific domestic hot water rate D stated by the manufacturer.3.2“summer”operating modeoperating mode in which the boiler only provides heating of the domestic water3.3 specific ratethe domestic hot water rate declared by the manufacturer,corresponding to a mean temperature rise of 30 K,that the boiler can supply in two successive delivery periodsSymbol:D;Unit:litres per minute(l/min).3.4 nominal domestic hot water heat inputthe value of the heat input in the domestic hot water mode indicated by the manufacturerSymbol:Qnw;Unit:kilowatt(kW).3.5 maximum water service pressurethe maximum pressure permitted in the domestic water circuit,as declared by the manufacturerSymbol:PMW;Unit:bar.3.6 tankreservoir of domestic water3.7 thermal storeheat reservoir sited mainly in heating water,as opposed to the domestic hot water storage in the tankw w w.b z f x w.c o mEN 625:19956 BSI 08-19993.8 temperature relief valvea valve that opens automatically at a given temperature of maximum 100 C to discharge the domestic hot water3.9 proportional control of the domestic hot water operationmeans of control in which the gas rate is subordinated proportionally to the domestic hot water rate;the proportioning factor may be adjustable3.10 thermostatic control of the domestic hot water operationmeans of control in which the gas rate is subordinated to a thermostatic device controlling the domestic hot water temperature,the set point of the device may be adjustable3.11 temperature holding thermostata device which maintains the water in the tank or the thermal store at a given temperature4 Constructional requirementsIt is checked that the assembly meets constructional requirements by visual examination of the boiler and possibly the tank,and also by inspection of the technical file.4.1 Materials and method of construction of components of the domestic water circuitMaterials shall be appropriate for their use,under intended application and at the maximum water pressure stated by the manufacturer.The requirements relating to thermal insulation and its use specified in the“boiler standards”only apply to parts of the domestic water circuit likely to come into contact with flames or sited close to the combustion products outlet.The materials of the parts containing domestic water shall not affect the quality of the domestic water in respect of either health or taste.The whole of the domestic hot water circuit shall be made up of corrosion resistant materials or shall be protected against corrosion.4.2 Domestic water connectionsThreaded connections shall comply with ISO 228-1 or ISO 7-1.If copper tubes are used for the connection,the end of the tube shall comply with ISO 274.In accordance with the manufacturers instructions,the domestic water circuit shall be able to be drained,without the discharge of water compromising electrical safety.4.3 Soundness of the domestic water circuitThe domestic hot water circuit and the heating circuit shall be separate.If an actuator or a control has a sliding shaft or a link with the diaphragm separating:the gas circuit and the heating water circuit;the heating water circuit and the domestic water circuit;the gas circuit and the domestic water circuit;there shall be an air vent between these circuits.The area of this aperture shall be at least 19 mm2 and it shall be possible to introduce a 3,5 mm pin gauge into it.4.4