SIST EN 1749:2020

SLOVENSKI STANDARD
SIST EN 1749:2020
01-april-2020
Nadomešča:
SIST-TP CEN/TR 1749:2014
Razvrščanje plinskih aparatov glede na način dovajanja zgorevalnega zraka in
odvajanja produktov zgorevanja (tipi)
Classification of gas appliances according to the method of supplying combustion air and
of evacuation of the combustion products (types)
Klassifizierung von Gasgeräten nach der Art der Verbrennungsluftzuführung und
Abgasabführung (Arten)
Classification des appareils utilisant les combustibles gazeux selon le mode d'amenée
d'air comburant et le mode d'évacuation des produits de combustion (types)
Ta slovenski standard je istoveten z: EN 1749:2020
ICS:
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
SIST EN 1749:2020 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 1749:2020

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SIST EN 1749:2020


EN 1749
EUROPEAN STANDARD

NORME EUROPÉENNE

January 2020
EUROPÄISCHE NORM
ICS 91.140.40 Supersedes CEN/TR 1749:2014
English Version

Classification of gas appliances according to the method of
supplying combustion air and of evacuation of the
combustion products (types)
Classification des appareils utilisant les combustibles Klassifizierung von Gasgeräten nach der Art der
gazeux selon le mode d'amenée d'air comburant et le Verbrennungsluftzuführung und Abgasabführung
mode d'évacuation des produits de combustion (types) (Arten)
This European Standard was approved by CEN on 13 October 2019.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.

This European Standard exists 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1749:2020 E
worldwide for CEN national Members.

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SIST EN 1749:2020
EN 1749:2020 (E)
Contents Page
European foreword . 3
Introduction . 5
1 Scope . 6
2 Normative references. 6
3 Terms and definitions . 6
4 General scheme . 6
4.1 General . 6
4.2 Type A . 7
4.3 Type B . 7
4.4 Type C . 9
5 Supplementary classification scheme for type A and type B appliances fitted with
particular safety devices . 14
6 Supplementary classification scheme for type B appliances for use in limited
installation conditions . 14
)
6.1 Type B appliance utilizing a third subscript “D” . 14
)
6.2 Type B appliances utilizing a third subscript “P” . 14
7 Supplementary classification scheme for type C appliances for use in limited
installation conditions — Type C appliances utilizing a third subscript “R” . 15
1
Annex A (normative) Classification according to the evacuation of the combustion products
and air inlet . 16
Annex B (informative) Special appliance classification (types) . 37
Annex C (informative) Appliance types designed for connection to separate chimney
products . 48

2

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SIST EN 1749:2020
EN 1749:2020 (E)
European foreword
This document (EN 1749:2020) has been prepared by Technical Committee CEN/TC 238 “Test gases,
test pressures, appliance categories and gas appliance types”, the secretariat of which is held by AFNOR.
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 July 2020, and conflicting national standards shall be
withdrawn at the latest by July 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN/TR 1749:2014.
The main changes compared to the previous edition are listed below:
— editorial changes, a reviewed wording and a reviewed structure compared to the TR version
(CEN/TR 1749:2014);
— some technical items generally described in the foreword of the former TR are now included in the
scope or in other clauses of the standard (1; 4.1; 4.4);
— a clause on normative references has been included (Clause 2);
— a clause on terms and definitions has been included (Clause 3);
— examples of reworded clauses:
— Type B (4.3);
— Type C6 (4.4);
— Type C(11) (4.4);
— Type C(13) (4.4);
— Type C(14) (4.4).
— a key for figures has been added and some figures have been modified, according to the key adopted
(Annex A);
— Annex B has a wider application than Germany. Due to this change, the former Annex D has been
deleted;
— Annex C replaces the former Annex E;
— The former Annex C has been deleted.
The user is advised to compare the previous text with the current version.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
3

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SIST EN 1749:2020
EN 1749:2020 (E)
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
4

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SIST EN 1749:2020
EN 1749:2020 (E)
Introduction
This document has been prepared to provide reference scheme for classification of gas appliances to
CEN Technical Committees who are preparing European Standards for appliances burning combustible
gases.
It gives details of a general scheme for the classification of such appliances according to the method of
air supply and evacuating the combustion products. This document concerns gas appliances that are
intended to be installed within buildings or outside buildings. Nevertheless, it is recognized that this
appliance classification scheme could be utilized in other circumstances. For example, in the case of
appliances capable of utilizing other fuels.
This form of appliance classification is widely used in the preparation of European Standards for gas
appliances to identify the requirements and methods of test that are applicable to the various methods
of evacuating the combustion products and air supply. Appliances classified in this way are generally
described as “types” and this description has been retained for the purposes of this document.
The definitions are written intentionally in very general terms in order to cover any possible variations
in the basic appliance types.
The main purpose of the document is to promote harmonization in the classification of appliance types.
This should ensure that there is a clear understanding of the various appliance types and will avoid
confusion arising from Technical Committees describing them in different ways. CEN Technical
Committees are therefore requested to use this document as reference in all circumstances in which it is
appropriate. They should not deviate from it unless there are relevant technical reasons for doing so.
In the preparation of this scheme it was noted that there were methods of evacuating combustion
products that were particular to a specific Technical Committee or to a particular gas appliance. These
particular methods have not been included in the present scheme because, as indicated above, the main
purpose of the scheme is to promote harmonization across Technical Committees.
However, it is intended that this scheme should be reviewed from time to time in order to consider its
extension to other, possibly new, methods of evacuating combustion products. At that time, such specific
methods of evacuating combustion products may be included at the request of the Technical
Committees concerned.
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SIST EN 1749:2020
EN 1749:2020 (E)
1 Scope
This document gives details for the classification of gas appliances according to the method of supplying
combustion air and of evacuating the combustion products (types). This classification refers to gas
1
appliances that are intended to be installed within buildings and/or outside of the building .
The document classifies appliances as type A, B or C according to the basic principle for the evacuation
of the combustion products and air inlet.
This document is the reference for the harmonization of product standards, for the preparation of
installation standards and for the common understanding of the types of gas appliances.
This document is neither an installation standard nor a product standard.
In references to a gas appliance or gas appliances connected via “its” or “their” duct or ducts, it is
intended that the air inlet duct and/or the discharge duct for carrying any combustion products are part
of the gas appliance. This means that such ducts are certified together with the gas appliance.
Informative Annex C identifies appliance types that are designed for connection to separate chimney
products, which may be part of the construction of the building.
In terms of this document, a “single duct” is a flue duct designed and capable of discharging the
combustion products and/or air inlet duct for the air supply for only one appliance.
In terms of this document, a “common duct” is a flue duct designed and capable of discharging the
combustion products and/or air inlet duct for the air supply for more than one appliance.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp/ui
4 General scheme
4.1 General
The general scheme for Type A, Type B and Type C appliances is given in 4.2, 4.3 and 4.4 respectively.
A series of subscript numbers is used in addition to these letters to identify specific variations within
these basic principles.
Where this first subscript number exceeds “9” it is given in brackets to clarify that it is a single subscript
number and not two subscript numbers.

1) If the appliance is installed outside of the building (if this circumstance is explicitly allowed by the
manufacturer) it will not change its classification (i.e.: a type B appliance will remain a type B if installed
53 53
outside according to manufacturer instructions). These appliances are subject to specific additional requirements
and tests, according to specific product standards.
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EN 1749:2020 (E)
The last subscript number of each specific variation indicates the absence or presence of an integral fan
for the supply of combustion air and/or for the evacuation of the combustion products.
If the last subscript number is “1”, no integral fan for the supply of combustion air and/or for the
evacuation of the combustion products is present. Where a fan is present, the numbers 2, 3 or 4 are
given. These three numbers are used solely to identify the location of this fan.
Figures are also given in Annex A to assist in the identification of the various appliance types.
Those pictures are to be considered as examples; for each type, they do not represent all the possible
details of applications.
In order to provide information about appliance types that are recognized in certain CEN Member
States, Annex B has been included with reference to subscript letter “X".
4.2 Type A
An appliance not intended for connection to a flue or to a device for evacuating the combustion products
to the outside of the room in which the appliance is installed.
Type A . An appliance without a fan.
1
Type A . An appliance with a fan downstream of the combustion chamber/heat exchanger.
2
Type A . An appliance with a fan upstream of the combustion chamber/heat exchanger.
3
4.3 Type B
An appliance intended to be connected to a flue that evacuates the combustion products to the outside
of the room containing the appliance. The combustion air is drawn directly from the room.
Type B . A type B appliance incorporating a draught diverter, marketed without duct systems, intended
1
to be connected to a separately approved and marketed system for discharge of the combustion
products.
Type B . A natural draught type B1 appliance.
11
Type B . A type B appliance designed for a natural draught flue incorporating a fan downstream of
12 1
the combustion chamber/heat exchanger and upstream of the draught diverter.
Type B . A type B appliance designed for a natural draught flue incorporating a fan upstream of the
13 1
combustion chamber/heat exchanger.
Type B . A type B appliance having an integral fan downstream of both the combustion
14 1
chamber/heat exchanger and the draught diverter.
Type B . A type B appliance without a draught diverter, marketed without duct systems, intended to be
2
connected to a separately approved and marketed system for discharge of the combustion products.
2)
Type B . A natural draught type B appliance.
21 2
Type B . A type B appliance incorporating a fan downstream of the combustion chamber/heat
22 2
exchanger.

2) A type B appliance will not generally be included in the scope of European Standards for gas appliances.
21
However, it may apply in special circumstances, e.g. gas-fired incinerators.
7

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EN 1749:2020 (E)
Type B . A type B appliance incorporating a fan upstream of the combustion chamber/heat
23 2
exchanger.
Type B . A type B appliance without a draught diverter, which is designed for connection via its
3
concentric duct to a common duct system. This common duct system consists of a single natural draught
flue. All pressurized parts of the appliance containing combustion products are completely enclosed by
parts of the appliance supplying combustion air. Combustion air is drawn into the appliance from the
room by means of a concentric duct, which encloses the flue. The air enters through defined orifices
situated in the surface of the duct.
Type B . A natural draught type B appliance.
31 3
Appliances of this type are not foreseen.
Type B . A type B appliance incorporating a fan downstream of the combustion chamber/heat
32 3
exchanger.
Type B . A type B appliance incorporating a fan upstream of the combustion chamber/heat
33 3
exchanger.
Type B . A type B appliance, incorporating a draught diverter, that is designed for connection via its
4
flue duct to its flue terminal.
3)
Type B . A natural draught type B appliance.
41 4
Type B . A type B appliance designed for a natural draught flue incorporating a fan downstream of
42 4
the combustion chamber/heat exchanger and upstream of the draught diverter.
Type B . A type B appliance designed for a natural draught flue incorporating a fan upstream of the
43 4
combustion chamber/heat exchanger.
Type B . A type B appliance having an integral fan downstream of both the combustion
44 4
chamber/heat exchanger and the draught diverter.
Type B . A type B appliance, without a draught diverter, that is designed for connection via its flue duct
5
to its flue terminal.
4)
Type B . A natural draught type B5 appliance.
51
Type B . A type B appliance incorporating a fan downstream of the combustion chamber/heat
52 5
exchanger.
Type B . A type B appliance incorporating a fan upstream of the combustion chamber/heat
53 5
exchanger.

3) Type B appliances installed in mobile homes (caravan holiday homes) are commonly described as “closed
41
flue” appliances; this terminology being used in EN 1949, which covers the installation of such appliances.
4) A type B appliance will not generally be included in the scope of European Standards for gas appliances.
51
However, it may apply in special circumstances, e.g. gas-fired incinerators.
8

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EN 1749:2020 (E)
4.4 Type C
An appliance in which the combustion circuit (air supply, combustion chamber, heat exchanger and
evacuation of the combustion products) is sealed with respect to the room in which the appliance is
installed.
Type C . A type C appliance that is designed for connection via its ducts to its horizontal terminal,
1
which at the same time admits fresh air to the burner and discharges the combustion products to the
outside through orifices that are either concentric or close enough to come under similar wind
conditions.
Type C . A natural draught type C appliance.
11 1
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
12 1
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
13 1
exchanger.
5)
Type C . A type C appliance connected via its two ducts to a common duct system serving more than
2
one appliance. This system consists of a single duct, which supplies the combustion air and evacuates
6)
the combustion products .
Type C . A natural draught type C appliance.
21 2
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
22 2
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
23 2
exchanger.
Type C . A type C appliance that is designed for connection via its ducts to a vertical terminal, which at
3
the same time admits fresh air to the burner and discharges the combustion products to the outside
through orifices that are either concentric or close enough to come under similar wind conditions.
Type C . A natural draught type C appliance.
31 3
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
32 3
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
33 3
exchanger.
7)
Type C . A type C appliance connected via its two ducts to a common natural draught duct system
4
designed for more than one appliance. This common duct system consists of two ducts connected to a
terminal, which at the same time admits fresh air to the burner and discharges the combustion products
to the outside through orifices that are either concentric or close enough to come under similar wind
conditions.

5) This common duct system is part of the building and not a part of the appliance.
6) This appliance type is now obsolete and unlikely to be called up in future European Standards for gas
appliances.
7) This common duct system is part of the building and not a part of the appliance.
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Type C . A natural draught type C appliance.
41 4
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
42 4
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
43 4
exchanger.
Type C . A type C appliance connected via its separate ducts to its separate terminals for the supply of
5
combustion air and the evacuation of the combustion products. These ducts may terminate in zones of
different pressure.
Type C . A natural draught type C appliance.
51 5
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
52 5
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
53 5
exchanger.
Type C . A type C appliance which is intended to be connected to a separately approved and marketed
6
system for the supply of combustion air and discharge of the combustion products.
Pictures for type C appliances have not been included. This is because such appliances are marketed
6
without duct systems. When installed such an appliance will have a configuration similar to one of the
arrangements shown for other type C appliances, according to manufacturer’s instructions.
Appliance Technical Committees have the responsibility for inclusion of requirements and methods of
test in their standards to ensure that type C appliances are suitable for their intended method of
6
supplying combustion air and of evacuation of the combustion product.
Type C . A natural draught type C appliance.
61 6
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
62 6
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
63 6
exchanger.
Type C . A type C appliance in which the combustion air supply and the combustion products
7
evacuation is provided by its two vertical ducts. The combustion air is taken from a loft and the
combustion products are discharged above the roof. A draught diverter is incorporated in the
8)
combustion products evacuation duct at a location above the combustion air inlet orifice(s) .
Type C . A natural draught type C appliance.
71 7
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
72 7
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
73 7
exchanger.

8) This appliance type is now obsolete and unlikely to be called up in future European Standards for gas
appliances.
10

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EN 1749:2020 (E)
9)
Type C . A type C appliance connected via one of its ducts to a single or common duct system . This
8
duct system consists of a natural draught duct (i.e. not incorporating a fan) that evacuates the
combustion products. The appliance is connected via a second of its ducts to a terminal, which supplies
air to the appliance from outside the building.
10)
Type C . A natural draught type C appliance.
81 8
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
82 8
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
83 8
exchanger.
Type C . A type C appliance that is designed for connection via its flue duct to its vertical terminal and
9
via its air inlet duct to an existing vertical duct. The terminal at the same time admits fresh air to the
burner and discharges the combustion products to the outside through orifices that are either
concentric or close enough to come under similar wind conditions.
11)
The air inlet duct , or part of it, is an existing vertical duct within the building, e.g. a converted
chimney.
Type C .A natural draught type C appliance.
91 9
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
92 9
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
93 9
exchanger.
12)
Type C A type C appliance connected via its two ducts to a common duct system designed for
(10)
more than one appliance. This common duct system consists of two ducts connected to a terminal,
which at the same time admits fresh air to the burner and discharges the combustion products to the
outside through orifices that are either concentric or close enough to come under similar wind
conditions.
The C appliance is designed to become connected to a common duct system that is designed to
(10)
operate under the conditions where the static pressure in the common flue duct might exceed the static
pressure in the common air duct.
Type C . A type C appliance incorporating a fan downstream of the combustion chamber/heat
(10)2 (10)
exchanger.
Type C . A type C appliance incorporating a fan upstream of the combustion chamber/heat
(10)3 (10)
exchanger.

9) This single or common duct system is part of the building and not a part of the appliance.
10) A type C appliance will not generally be included within the scope of European Standards for gas
81
appliances.
11) The vertical air inlet duct is part of the building and not a part of the appliance.
12) This common duct system is part of the building and not a part of the appliance.
11

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EN 1749:2020 (E)
Type C A type C appliance consisting of an assembly of two or more generally identical appliance
(11).
modules, connecting ducts, a common flue duct, a common air duct, where the static pressure in the
common flue ducts might exceed the static pressure in the air ducts and where the orifices of air duct
and the flue duct to the outside are either concentric, or close enough to come under similar wind
conditions.
A C appliance is designed to be assembled by connecting its appliance modules via its ducts to its
(11)
common ducts. These common ducts consist of two ducts connected to their terminals, which at the
same time admit fresh air to the burner of each appliance module, and discharges the combustion
products of each appliance module to the outside through orifices that are either concentric or close
enough to come under similar wind conditions. The appliance has a single air inlet and a single flue
outlet.
The C appliance, made by an assembly of two or more modules, is designed as a single appliance;
(11)
each appliance module is capable of independent operation and it consists of a heat exchanger, burner,
control and safety devices.
The C appliance is evaluated and certified in analogy with the types C , C , C .
(11) 1 3 5
Type C . A type C appliance is an assembly of two or more appliance modules each
(11)2 (11)
incorporating a fan downstream of the combustion chamber/heat exchanger.
Type C . A type C appliance is an assembly of two or more appliance modules each
(11)3 (11)
incorporating a fan upstream of the combustion chamber/heat exchanger.
13)
Type C . A type C appliance connected via one of its ducts to a common flue duct system . The
(12)
appliance is connected via a second of its ducts to its terminal, which supplies
...