EN 483:1999/A2:2001
(Amendment)Gasfired central heating boilers  Type C boilers of nominal heat input not exceeding 70 kW
Gasfired central heating boilers  Type C boilers of nominal heat input not exceeding 70 kW
This amendment 2 will incorporate in EN 483:1999 the EU Directive 92/42/EEC on efficiency requirements.
Heizkessel für gasförmige Brennstoffe  Heizkessel des Typs C mit einer Nennwärmebelastung gleich oder kleiner als 70 kW
Chaudières de chauffage central utilisant les combustibles gazeux  Chaudières des types C dont le débit calorifique nominal est inférieur ou égal à 70 kW
Plinski kotli za centralno ogrevanje  Tip kotlov C z imensko močjo do vključno 70 kW  Dopolnilo A2
General Information
RELATIONS
Standards Content (sample)
SLOVENSKI STANDARD
SIST EN 483:2001/A2:2002
01april2002
3OLQVNLNRWOL]DFHQWUDOQRRJUHYDQMH7LSNRWORY&]LPHQVNRPRþMRGRYNOMXþQR
N:'RSROQLOR$Gasfired central heating boilers  Type C boilers of nominal heat input not exceeding 70
Heizkessel für gasförmige Brennstoffe  Heizkessel des Typs C mit einerNennwärmebelastung gleich oder kleiner als 70 kW
Chaudieres de chauffage central utilisant les combustibles gazeux  Chaudieres des
types C dont le débit calorifique nominal est inférieur ou égal a 70 kWTa slovenski standard je istoveten z: EN 483:1999/A2:2001
ICS:
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
97.100.20 Plinski grelniki Gas heaters
SIST EN 483:2001/A2:2002 en
200301.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
 Page: 1 SIST EN 483:2001/A2:2002
 Page: 2 
SIST EN 483:2001/A2:2002
EUROPEAN STANDARD
EN 483:1999/A2
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2001
ICS 91.140.10
English version
Gasfired central heating boilers  Type C boilers of nominal heat
input not exceeding 70 kW
Chaudières de chauffage central utilisant les combustibles Heizkessel für gasförmige Brennstoffe  Heizkessel des
gazeux  Chaudières des types C dont le débit calorifique Typs C mit einer Nennwärmebelastung gleich oder kleiner
nominal est inférieur ou égal à 70 kW als 70 kWThis amendment A2 modifies the European Standard EN 483:1999; it was approved by CEN on 9 June 2001.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of this
amendment into the relevant national standard without any alteration. Uptodate lists and bibliographical references concerning such
national standards may be obtained on application to the Management Centre or to any CEN member.
This amendment 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 Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 483:1999/A2:2001 E
worldwide for CEN national Members. Page: 3 
SIST EN 483:2001/A2:2002
EN 483:1999/A2:2001 (E)
Foreword
This Amendment EN 483:1999/A2:2001 to the EN 483:1999 has been prepared by Technical
Committee CEN/TC 109 "Gasfired central heating boilers", the secretariat of which is held by NEN.
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 January 2002, and conflicting national standards
shall be withdrawn at the latest by January 2002.This Amendment to the European Standard EN 483:1999 has been prepared under a mandate given
to CEN by the European Commission and the European Free Trade Association, and supports
essential requirements of EU Directive(s).For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
standard.This Amendment has been prepared to incorporate the EU Directive 92/42/EEC on efficiency
requirements in EN 483:1999.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
 Page: 4 SIST EN 483:2001/A2:2002
EN 483:1999/A2:2001 (E)
Renumber the existing table 18 to table 20.
6.7 Useful efficiencies
6.7.1 Useful efficiency at the nominal heat input
Replace the text by the following :
“ Under the test conditions of 7.7.1, the useful efficiency at the nominal heat input, or the
maximum heat input for range rated boilers, expressed in percent, shall be at least :
84 2 log P10 n
where :
P is the nominal output (maximum output for range rated boilers), expressed in kilowatts (kW).
In addition, for range rated boilers, the efficiency at a rate, corresponding to the arithmetic mean
of the maximum and minimum heat input, expressed in percent, shall be at least:84 2 log P
10 a
where :
P is the arithmetic mean of the maximum and minimum useful heat output as stated by the
manufacturer, expressed in kilowatts (kW).”6.7.2 Useful efficiency at part load
Replace the text by the following :
“ Under the test conditions of 7.7.2, the useful efficiency for a load corresponding to 30 % of the
nominal heat input (or the arithmetic mean of the maximum and minimum heat input for range
rated boilers), expressed in percent, shall be at least :80 3 log P
10 i
where :
P is the nominal output P , or the arithmetic mean P of the maximum and minimum useful
i n aoutput as stated by the manufacturer for range rated boilers."
7.7.1 Useful efficiency at the nominal heat input
Add at the end of this subclause a new paragraph as follows :
" It is checked that the requirements of 6.7.1 are met."
7.7.2 Useful efficiency at part load
Replace the text by the following :
“7.7.2.1 General
To determine the useful efficiency at a load corresponding to 30 % of the nominal heat input, or
the arithmetic mean of the maximum and minimum heat input for range rated boilers, the
manufacturer shall declare whether the direct method or the indirect method is used.
It is checked that the requirements of 6.7.2 are met. Page: 5 
SIST EN 483:2001/A2:2002
EN 483:1999/A2:2001 (E)
7.7.2.2 Direct method
7.7.2.2.1 General
The boiler is installed as stated in 7.1.6 and supplied with one of the reference gases as for the
determination of the useful efficiency at nominal heat input or at the arithmetic mean of the
maximum and minimum heat input in the case of range rated boilers.Throughout the test, the water volume rate is maintained constant within ± 1 %, taking into
account temperature variations, and the pump operates continuously.7.7.2.2.2 Operating mode n 1
The boiler is fitted to the test rig illustrated in figure 15 (or any other test rig giving at least
comparable results and equivalent measurement accuracy’s).The boiler return temperature is held constant at (47 ± 1)°C, with a maximum variation in this
temperature of ± 1 K during the measurement period.If the boiler control does not permit operation at a return temperature that is low enough, the test
is carried out at the lowest return temperature compatible with the operation of the boiler.
A timepiece is fitted to the ambient temperature thermostat to obtain a working cycle of 10
minutes.The shutdown and operating times are calculated as indicated in table 18.
 Page: 6 
SIST EN 483:2001/A2:2002
EN 483:1999/A2:2001 (E)
Table 18  Calculation of the useful part load efficiency
Conditions of operation Heat input Cycle time (s) Meas. Useful efficiency (%)
1 30 % reduced rate
QQ03, t 600 =
2 u 2
2n 2
2 Full rate
+ 08, 
Q t Q t Pt
1 1 333s

180 Q 600 Q
100
t
QQ ) 100
1
Q Q
13 +
Q t Q t
1 3
1 3
Controlled off tt600 P
= permanent
ignition burner
180  600
Q Q
21 3
3 Reduced rate QQ03,
t = t 21
2n 21 + 08, 
21 Q t Q t Pt
21 21 333
Q Q
100
21 3
100
Q Q
t t
21 21 3 3
Controlled off = permanent
3 tt600
ignition burner
180  600
Q Q
122
1 22
4 Full rate Q = Q )
1 n
t = 1
1 + ( )
Q t Q t
1 22
1 22
Q Q 100 100
122
100
Q t Q t
1 1 22 22
Reduced rate
QQ03, tt600
22 n 22 1
180  600
Q Q
21 22
21 22
5 Reduced rate 1
QQ03,
t 21 Q + Q
21 n t t
21 21 22
21 22
 100 100
Q Q
21 22
100
Q + Q
t t
21 22
21 22
Reduced rate 2 QQ tt
03, 600
22 n 22 21
6 Full rate Q = Q t = measured value (see annex Q)
1 n 1
1 2
+ +,08 
Q t Q t Q t Pt
1 2 33s
1 2 3
( 180 )  (600  )
t Q t Q
1 1 1 3
100 100
Q t
Reduced rate 100
2
21 u
 + +
Q Q Q Q Q
t t t
23 1 1 2 2 3 3
Controlled off Q = permanent P
tt600()t
3 s
312
ignition burner
) Q is replaced by the arithmetic mean Q of the maximum and minimum heat input for rangerated boilers.
n a Page: 7 
SIST EN 483:2001/A2:2002
EN 483:1999/A2:2001 (E)
The temperatures are measured continuously directly on the flow and return of the boiler.
The boiler is considered to be in thermal equilibrium when the efficiency measurement of three
consecutive cycles, combining any two results from three, does not vary by more than 0,5 %. In this
case, the result is equal to the average value of at least three consecutive measurement cycles. For
any other case, the average value shall be calculated from at least ten consecutive cycles.
The respective gas and water consumption’s over complete cycles are measured.The efficiency is determined using the formula in 7.7.1.
A variation of ± 1 %, with respect to the 30 % of the nominal heat input is permitted. For variations up
to ± 2 % it is necessary to carry out two measurements, one above and one below 30 % of the nominal
heat input. The efficiency corresponding to 30 % is determined by interpolation.7.7.2.2.3 Operating mode n 2
The boiler is fitted to the test rig illustrated in figure 1 or 2 (or any other test rig giving at least
comparable results and equivalent measurement accuracy’s).The boiler flow and return temperatures and the operating and off cycles are given by the boiler
control. The temperatures are measured continuously as close as possible to the flow and at the return
of the boiler when (30 ± 2) % of the nominal input or the arithmetic mean of the maximum and
minimum input for range rated boilers, is drawn through the heat exchanger.The average water temperature shall be no less than 50 C.
If the boiler control does not permit operation at a return temperature that is low enough, the test is
carried out at the lowest return temperature compatible with the operation of the boiler.
The boiler is considered to be in thermal equilibrium when the efficiency measurement of three
consecutive cycles, combining any two results from three, does not vary by more than 0,5 %. In this
case, the result is equal to the average value of at least three consecutive measurement cycles. For
any other case, the average valu...
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